arch help!!!!!!!!!!!!!!!!!!!!!!!!!!

I am trying to buld 5 10ft long 5ft tall arch. i need help on how to do it.does anybody no how to do it (under 30$... PLEASE HELPPPPPPPPPPP!!!!

Question by vodo   |  last reply

Need Advise on Building Large Arch Gate

I am trying to make a large arch-like gate out of foam. It would be about 8' high, it would have to stand on its own, it would have to be able to be broken apart into pieces and needs to be able to last in the elements. I was thinking of buying wet foam blocks (foam used by florists) and binding sets of them together and using spray foam to cover the outsides and paint it grey to make it look like rocks. It would be held together with dowels through each set of foam and have an anchor at the bottom using dowels hammered into the ground.  Inspiration for this design came from the vault from the Borderlands game series I wanted to know if anyone has seen guides for making a fake stone arch or if anyone had ideas for making this (Especially if the ideas aren't too expensive) Thanks

Topic by BenH18   |  last reply

Instamorph Build Night at Arch Reactor Hackerspace, St. Louis, Missouri

On Tuesday, April 21st we held a build night at Arch Reactor (in St. Louis, Missouri) with Instamorph. There was a very excited turnout of over 15 people being introduced to the moldable plastic product. Some members incorporated their creations into existing projects, such as a loop to hold a weather balloon safely onto the quick release pipe during the pre-launch filling in order to measure the total lift without losing any of the gas. Another member created a diffuser for a LED project that used RFID tags to cause different combinations of colored LEDs to turn on when a tag was scanned.  Others experimented with the product to discover ways they might use Instamorph in other projects in the future. The big discoveries of the night were that any unused portions or failed creations could simply be placed back into the hot water and reshaped into version 2.0 or something new entirely and that once it cools Instamorph is virtually indestructible. See the photo of a flat sheet of it being bent into a taco shape. Process: We used an electric kettle to heat up our water to the correct temperature of 140 degrees F / 60 degrees C, and then poured it into small bowls. I had initially thought that each person could start with 3 ounces of the pellets, but the measuring cup that I brought only held 2 ounces. After heating that portion up in the water, we discovered that 2 ounces was plenty for most projects being considered. The member in charge of our workshop had asked those who did not have an idea for the Instamorph to consider making a hanger to hold individual shop safety glasses. He molded a piece into a design for that. Later it was discovered that the hearing protection holder dome in the shop was exactly the size to hold shop glasses. Attempts may be made later to fashion a "nosepiece" and "earpieces" from Instamorph and attach them to the dome to hold several pair of safety glasses on it instead of on the wall. It was also discussed to place a safety glasses holder at various stations throughout the shop to make them more accessible for users in the shop, and thus more likely to be worn.  Problems encountered:  The bowls that I had brought were plastic, so if the heated pellets were pressed into the bowl hard enough they would stick a little, but could be pushed off with just a little effort. In retrospect, I would use glass bowls the next time.  I would also consider using a crock pot to keep the water at a near constant temperature for any personal projects, but the electric kettle and bowls worked well for the build night. We also had an issue with the warmed Instamorph sticking to an acrylic roller and a plastic mold meant for cake decorating. It worked fine if the Instamorph had been allowed to cool while flattening it out by hand, then rolled. However, when it was removed from the water and immediately rolled, it cooled quickly and adhered to both the acrylic roller and the plastic mold. Much scraping, reheating, and elbow grease were applied in order to remove the Instamorph from those tools. Tools made from other materials might work better for this process. 

Topic by GeekTinker   |  last reply

Arch Reactor Member Projects

A forum to discuss the personal projects of members of Arch Reactor. These can be individual or collaborative works.

Topic by GeekTinker   |  last reply

Constant arc with a taser...need help!!

Can anyone give me some help on how to make a constant arching spark across 2 electrodes like a commercial taser?

Topic by PyroMonger   |  last reply

How can we make a arch out of discarded bike rims/wheels?

My fiance and I want to build a rounded arch out of discarded bike rims to use in our wedding ceremony next summer. We do not have welding equipment, which I imagine would be the easiest way to do this. Besides that, how could we do this? We'd love it to be rounded, but suggestions for a squared one would be ok, too. After the wedding the arch would live in our garden. Thank you in advance!

Question by    |  last reply

Arch Reactor Hackerspace At Critical Mass & Moving

Be a part of Arch Reactor's Move. Help our Hackerspace Double in Size & Increase Our Community Impact Come & help us to grow through our crowdfunding campaign! Learn more about the exciting things the educational non-profit, Arch Reactor is doing in St. Louis, Missouri. Arch Reactor is Moving Welcome to Arch Reactor, the St. Louis community educational 501(c)(3) nonprofit hackerspace (sometimes also referred to as a makerspace). We are the oldest and largest organization of it's type in the St. Louis area. We specialize in collaborative learning, a DIY attitude, and inspiring interest in S.T.E.M. related fields (Science, Technology, Engineering, & Mathematics). Our focus is on education and teaching classes in electronics, programming, manufacturing, robotics, woodworking, and arts that are open to the general public. We are currently in the process of relocating to a much larger building about one-and-a-half miles away, at 2215 Scott Avenue, St. Louis, Missouri. Where we will be breathing a new breath of educational maker life into an old building and local community. This gem of a building at our soon to become new location has a rich history of being home to the Dixie Cream Donut Flour Company for several decades. The building has basically been used as storage for almost 20 years.  However, the expanse of the first floor interior is in need of a complete overhaul in order to be transformed into the new and updated Arch Reactor. Our members and supporters have been planning, procuring, cleaning, and doing everything we possibly can in order to complete this move project. In order to make such a large undertaking possible, we need your support too! Also, please help by sharing this post on your social media! #education #hackerspace #makermovement #community #building #moving #makerspace

Topic by GeekTinker   |  last reply

Vaulted Dome Aquaponics Greenhouse Design

What do you think about this greenhouse design? It is for an aquaponics system. 192 sq ft so no permit is required in many areas. 9ft tall by 16ft wide, vaulted dome with center support for strong snow holding ability (snow should mostly slide off the vaulted dome anyway). Do you think people would want this in their yard if I offered to sell it to them?

Topic by Jaycub   |  last reply

How to make a cHAllenge? 0g Spacial Arch with clay concept

How do i sign in for a challenge? you know other websites were I could advertise this? like meetups events , other? I want to start a cloud for design concepts for 0 gravity Architecture - no straight walls


image comments test 2

Trying to make image comments firefox 3.0.5 on arch linux

Topic by 11010010110   |  last reply

Ible robot nemesis?

I new here so there might already be one, but how cool would an arch nemesis of the instructables robot be? he could boring bot or something. feel free to comment

Topic by sev17   |  last reply

Do you really think that it is possible ?

To build a suit like IRONMAN'S, Does the technology really exist and how would you begin and what kind a CAD software would you use to begin the design,To build an ARCH Reactor period let alone miniturize it? Does an ARCH reactor even exist or is it just a clever part of the comic book story line? And what about a repulsive ray? Does the techology exist , is it even feasible? Ad what about the head-up display that was in the suit ,and could it be hooked to a satellite computer for ground to air GPS, and how would you write the code for the software to hardware that does as of yet exist?

Question by compuman2153   |  last reply

Silhouette June 2015 Build Night at Arch Reactor Hackerspace, St. Louis, Missouri

On Tuesday, June 9th, the Arch Reactor Hackerspace (in St. Louis, Missouri) hosted a Build Night with the Silhouette Portrait. There were an excited dozen people who showed up for an introduction to the device. Many members were seeking to discover ways to use the device for current projects.  Others were eager to learn which materials the Portrait could cut, the limitations of the Silhouette Studio software, and how they might go about using the Silhouette Portrait for other projects in the future. Process: I already had the Silhouette Studio software downloaded to my laptop and had the Silhouette Portrait out on the large at the front of the our classroom space.  Those in attendance gathered around as I ran down the features of the device and software and we discussed the use of the cutting mat and how to set the depth of the blade. We then watched the introduction movie and a few others before attempting to use the device to cut a file.  The Arch Reactor already has a large vinyl cutter in our space, however it shares a keyboard, mouse, and monitor with our very popular laser cutter. Due to the popularity of the laser cutter, it is sometimes difficult for members to even learn how to use the vinyl cutter without making a special trip in on a day when few members are present. Plus, being a larger device, the learning curve seems a bit steep for those who have yet to learn how to use it. It can also only be utilized in our space. One advantage that was quickly noted for the Silhouette Portrait is that anyone can download the free software and design their project at home, save it to a flash drive or the cloud, then arrive at our location to complete their project using one of our computers or their own laptop. A second advantage is that being so small, the Portrait could be moved to any desk in our 2400 square foot location temporarily, or even checked out of the space by a member to be used at home for a few days. We can even bring it along with us to local demonstrations and interactively challenge others to be creative while introducing them to our hackerspace.  The Silhouette Studio software seems intuitive and one member remarked that it reminded her a lot of Inkscape, which several of our members are already familiar with. The portability of the unit is not something to be overlooked.  I can see this being very useful for projects that require the same print to be created repeatedly. Such as wedding invitations, or multiple t-shirts. The versatile amount of material that can be cut with it had many present talking about how they might use the Portrait. Troubles we encountered: The night wasn't without problems though. Aside from having trouble playing some of the videos, I had forgotten to bring my pack of white cardstock to the event. This prompted us to rather foolheartedly attempt to cut a file with a normal sheet of printer paper. We eagerly stuck the paper to the cutting mat and inserted it into the Portrait. A member attempted to send a file to it from his computer, but nothing happened with the device and he received a message that the cut was complete. I'm not sure if this was a driver issue, a software issue, or an issue with the cutting mat not having been installed properly. We then connected my laptop back to the Portrait and sent a test file to it. The cutting mat was pulled into the device and it began to cut the paper. The problem occurred once the Portrait was finished with the cut and we attempted rather unceremoniously to remove the cut paper from the mat. Normal printer paper sticks to the mat very well, especially with the first or second use. Of course it ripped the paper as we attempted to remove it from the cutting mat and we realized that a thicker cardstock would be needed. This was more naive beginner user error than anything else.  I do not recommend that you attempt using thin paper. A second issue was the discovery that the free Silhouette Studio software does not allow the import of .SVG files. Many members of our hackerspace are familiar with and use these files for projects. In order to import .SVG files, we would need to upgrade to the Designer Edition for $50 or the Business Edition for $100.  If the Silhouette Portrait gets used as much as I believe it will, this upgrade will likely be a no-brainer for us.  Once the paper had been carefully scraped from the cutting mat using a former plastic gift card, some of our members set out to make a cut from the Vellum that had been sent with the printer.  This proved to be easier to remove from the cutting mat and the members were very happy with the the lace designs they had cut. Additionally, some members used a few sheets of cardstock they already had to cut out some borders from the files that came with the Silhouette Studio software.  We are already looking at purchasing some accessories for the Portrait, such as Pens and additional cutting mats. The later would be a huge advantage because it would allow us to prepare a second material for the next cut while the first was being cut or removed from the mat.  Should the Portrait see as much use as I expect it will, we may be looking at other products from Silhouette, such as the Cameo, the Curio, and the Mint. Being used in a hackerspace by over 50 members, the size and additional versatility of Curio definitely would seem to fit our needs better. The additional thickness and variety of materials that could be used with it are of great interest to the creative tendencies of hackerspace members and makers.  We are also looking forward to Silhouette Link, a new feature coming to Silhouette Studio® that allows customers to send a cut job from any device directly to their Silhouette machine, remotely, through the use of a mobile device app. What I would have done differently:  Not only would I have tested the videos we watched on our projector prior to the meeting, but I would have remembered my cardstock on the night of the event. I also would recommend that anyone else hosting a Build Night use the Portrait to cut out several test files in a variety of materials. Definately take a look at the limitations of the Studio Software and decide if you want to upgrade to the Designer's edition for the importing of .SVG files or not, too. Conclusion: Overall, the night proved to be a successful introduction for several of our members to the Silhouette Portrait. I think all of us were inspired by what it can do for us as individuals and as a hackerspace.  We already have ideas to make a few t-shirts for an upcoming event using heat transfer vinyl and a logo.  I'm sure many projects will be sporting vinyl stickers and other materials that are cut with it. 

Topic by GeekTinker 

DIY tube and pipe roller

Anyone able to make a guide on how to create a DIY tube and pipe roller? Roller's is not the same as benders, benders make sharp bends while rollers make adjustable gradual long archs. Should be able to bend atleast 2" tubing and pipes. Best regards Tom

Topic by randomher0   |  last reply

Is it possible for me to mount a front on our oak kitchen cupboards?

They are good cabinets, but have that very dated looking arch on the top. Can anyone think of any solution to give the doors a new life without replacing them? We are going green and don't have much green either so bonus if it is eco- and wallet friendly.

Question by bunchaviolets   |  last reply

Motion Control Switch- triggering Elwire project- need HELP

I have a motion controlled light switch that activates a glowing aqua elwire arch. It lights up when anyone approaches the hallway. Problem is that the switch is allowing 3 volts through even when there is no motion. This measly 3v is enough to power the inverter and light the elwire. How can I add 3v of resistance to block that leakage?

Topic by Fotmasta   |  last reply

the vrvrvrvrvr sound produced by the Headphone when i touched the wall and the wires(going to the right) ?

I have my headphone on my head, then i happened to be touching the headphone's metal arch(at the top through which the wires reach the right speakers) and the wall of my room at the same time, so then i heard a vrvrvrvrvrvrvrvrvrvrvrvrvrvr sound . Could any one help me identify this phenomenon?

Question by lojha   |  last reply

Movable Solar Panel:- Sizing limits.

Hi folks looking to build a tracking solar panel for North and South directions. I have a few drawings made up but im stuck for the maths side of things as I have a size limit I need to stick to in. I need the panel to move by 15° towards north and towards south. So a 30° movement in total. What I have in mind if an arch where the panel will sit on which can be moved with a single piston placed on the South end of the panel. This is to contract and expand to move 15° up and 15° down. My size limit is the panel must not exceed 200mm or 20cm in real money when at its maximum positions. I have assumed a 2 meter long panel (or array of panels in a frame) So because of this im a bit unsure about how to tackle the maths side of things to work out the arch's profile to meet this criteria. Anyone got any words of wisdom? The 200mm limit is the max UK law allows me to play around with the panels maximum position.

Topic by apmaman   |  last reply

Small Mural

I has been 15 or so years since I attempted any serious wall art. Here is a mural I am still working on. I hope to add more pics to share the evolution of a single wall.  Next layer is the structure of the arches as I attempt to create aged and distressed stone archways wall. Thanks for checking it out!  Open to constructive criticism.  I couldn't get the order of progress when I uploaded. 

Topic by simply.alon   |  last reply

Sometimes I accidently 'flip' On-Off-On the power switch of my TFT LCD, could this cause any harm to the LCD's circuits? Answered

Or the appliance has some protection against this? (my worry is that such on-off flipping cause some surge or arch). It's said that in modern PC LCD monitors like mine (where the power switch is just a touch sensitive area of the front bevel) most of the actual circuitry remains on all the time so I have nothing to worry about, is that correct?

Question by allymcbeal   |  last reply

Can't save profile website url with https://

Hi, I'm trying to add a profile URL at the settings page. Our website is https only, but if I add an URL starting with "https://", then after save the "http://" part will be added to the front of the URL, resulting in something like "http://". Attached screenshot after saving. I don't think it's a system issue, but anyways, same experience both with Firefox 39.0 and Chromium 44.0.2403.107, on Arch Linux 64-bit. The problem is at on the Settings tab. Cheers!

Topic by taipeihackerspace   |  last reply

Man Vs. Cartoon !

Did anyone catch this episode of Man Vs. Cartoon, on Tru TV ? Watch as a team of the country's brightest minds takes on the devices and techniques used by Wile E. Coyote in his vain attempts to snare his arch-enemy the Road Runner. See if expertise, years of training and the best equipment that money can buy will be enough to actually make Coyote's flawed Acme Company machines work.let's make some of the Wile E.'s stuff WORK !AND some character Bio'sSome of the future TESTS

Topic by Goodhart   |  last reply

Facebook connect doesn't work on Firefox (linux)

Hello, Facebook connect doesn't work on firefox 20.0.1. O.S: Archlinux, kernel version: 3.8.7-1-ARCH. It works on chromium 26.0.1410.63 (192696). Step to reproduce: from the main page, choose facebook login from the upper right corner. Nothing happens when I click on it. If I copy the URL in a new tab, at least I get an error from facebook: "Given URL is not permitted by the application configuration.: One or more of the given URLs is not allowed by the App's settings. It must match the Website URL or Canvas URL, or the domain must be a subdomain of one of the App's domains."

Topic by davethecipo   |  last reply

could someone please build an electric copper bonsai tree? thanks!

Hi peeps! I was thinking the other day that I would LOVE to see one of those handmade copper bonsai trees (like these ones ) inside a plasma ball, with electricity arching across branches and so on. Either that or two of them side by side forming an electric Jacob's Ladder?? But I don't know how to make one. Does anyone want to make one - if possible - and show me? I have a neon light ballast and some time on my hands, I'd love to try this! Cha cha!

Topic by damianzuch   |  last reply

Gcode for arduino

So this is an idea but also a question. so I want to make a cnc but rather then going down the conventional way I want a plug and play system. the idea is to use something like things I want to add is its own driver and nano, 2 endstops and a rotary encoder.Are Arduino nano's capable of taking g-code, sending to nema while reading an encoder and endstops?also is there a way to have on the nano a limit on movement. so it knows its length (defined by user) and then if a code comes in that will make it go past the endstop it sends error code?also this needs to run on i2c or usb and synchronise with other similiar setups for better archs and such?

Question by plucas1   |  last reply

Can't change license of published instructable

Hi, I have some instructables that was posted under one license by a team member (e.g. CC-BY-SA) and I want to re-licese (to "CC-BY"). I was trying to do the following: * go to the instructable in question * hit Author Options: Edit, * hit publish * change the license value to the desired one * hit save I got a message in the UI that "saved", but if I refresh on the page, or go back to the instructable in question, it still shows the original license, and nothing has actually been saved. Any idea? Tried both Firefox 39.0 and Chromium 44.0.2403.107, on Arch Linux 64-bit, without success (license cannot be changed). Tried for example  this, this, or this instructables.

Topic by taipeihackerspace   |  last reply

cnc smoothrods are not parallel?

Hey guys i am 19 years old and a few of us are trying to make a CNC. well we are planing to use smooth rods for support .well the problem now is when we make the arch for y axis the holes that we made for the smooth rods to go through is not perfectly parallel ,so this resulted in the smooth rods to be slightly non parallel 4-5mm over 1 meter that's the error.Well my IITan friend is so stubborn in saying that this small error will make the carriage to stall. So if there are any experienced personel please clarify this doubt for me, because this error wont matter so much according to my calculations. thank you for looking into the matter

Question by cthaliyath   |  last reply

How to moderate new submissions to a Community Group Workshop?

I am the owner/moderator for the Community Group Workshop, Arch Reactor Hackerspace. I am currently am able to moderate who becomes members and I can edit the Workshop page. I have added my own new Instructables to the Workshop and received a message that the moderator would need to approve them.  However, there is no place that I can find to moderate the submitted Instructables from myself or other members of our hackerspace's Workshop. Under "Admin Features" the only choices I have are: "Manage Admins" "PM Group", "Edit Group", and "Categories". If I turn off the "Moderate New Instructables", it will allow submitted Instructables to post, but I'm not able to moderate the new submissions individually. There also seems to be a second bug that does not allow me to add more Categories to my Workshop. Typing a new Category name on a second line will only add the second category to the end of the first one.  It is as thought I'm only allowed to have one Category. Any assistance would be extremely helpful. Sincerely, Gene

Topic by GeekTinker   |  last reply

Anyone have ideas for mosquito netting a bed when you can't hang the net from the ceiling?

I'm staying in a room in Southern Mexico with no AC for the next couple months. There is a lot of Dengue and Chagas  transmission here, so I'm worried about the bugs. We leave the windows open at night because of the heat, and do not have screens for them. Even if we did have screens the insects could get in through the substantial cracks in the doors. I think netting the bed is the best idea, but I can't hang the net from the ceiling. It is too high, and the owner of the house wouldn't let me screw any eye hooks into it even if I had access to a ladder to get to it. I have been thinking about building a frame around the bed that I could hang the net from, but I don't have any tools here with me and would prefer a simpler solution if I can find one. Maybe even something like a couple wire arches over the bed to drape the net over, but I'm not sure what material would be best for that.  I'm not super handy, so I'm hoping you guys can help me out with some ideas!

Question by Daphnesilke   |  last reply

Can you insulate the primary coil of a Tesla coil?

Hello,    I am trying to build a tesla coil using a new design relating to a thesis paper I am working on. Due to spacial restraints my primary coil will be close to the secondary coil. I know I have seen others use insulated braided copper wire as their primary. I want to stay with 1/4" copper tubing if at all possible so I wanted to ask what affects it would have if I used heat shrink tubing on the copper tubing. I am aware the higher frequency voltage runs along the skin of the tubing since that is least resistive at that point. A for the power and caps I am using the following: three NSTs of which two are 15kv @ 30 miliamps and one 12kv @ 30 miliamps, 13 CD 2000VDC @ .15nf caps on each 15kv NST and 10 of the same caps on the 12kv NST. The spark gap is static for now.  I want to prevent arching as much as possible in the small space. Any advice is greatly appreciated. Some of the information relating to the thesis paper I cannot release due to a serious concern of being scooped before publication.  Thank you. :)

Topic by XsFacade   |  last reply

P.M. D.C. Motor for Treadmill

Hi I am working on an Image 15.0 R Treadmill. As soon as you start it , it shuts down as if the circuit has been interrupted. I unhooked the drive belt so that there was no resistance to it and it does the same still. The speed sensor seems to be working okay so I pulled the controller (board) and tried re-flowing it. as I flip the treadmills switch on not starting the treadmill-just turning the power on the motor runs for about 3 seconds. Because the cover is off while I am working on it I can see that during that 3 second window the motor has a spark (bolt) from one of the bolts to the post (I think stater) the one that if the motor were disassembled the part spinning inside the copper wind. I don't remember what it's called (armature?) Anyway this arching does not re-occur unless I completely unhook the board once more and re-assemble. After re-flow the motor still just begins to load (start) bumps about 1/2 a rotation and stops. I read an article here that Iceng had commented about bringing his P.M. D.C. Motor model # c335483304 back to is the exact girlfriend has been on me about fixing her treadmill so here I am. Anything would be of great interest and help to me. Thanks a million in advance. Troy

Topic by ill build u one   |  last reply

What New Useful Products Have You Recently Become Acquainted With ?

Here is My list. I recently saw an ible about sugru. Had neverheard of it, before  but can see its usefulness. Kind of expensive and not generally available. Have seen polymer clays, but cant see how it would replace epoxy putty Available at craft shops. Have heard Rescue tape ( fusible silicon ) . I haven't had a use for it, but it seems to be a great repair tape. It was available at Craftwood  Lumber, so it is a mass market product. Expensive, but can see it's potential worth. I'll wait til. I need it before I buy it. The oscillating tools have come down in price. Not exactly new, but extremely useful especially for people whose shop is their desk or kitchen table. If I were to have one power tool, it probably would still be the cordless drill driver. But if I were allowed a second power tool, this would be it. Blades are expensive.  Demolition Bags are very useful and cheap and generally available. I recently saw a device for bending PVC pipe. I have avoided using PVC because of the joints. I prefer thin metal conduit because it can be bent with the pipe bender I was able to acquire. That being said, the Pipe Viper may  be worthwhile. I am considering a small greenhouse made of arched PVV pipe and clear sheeting.  

Topic by Wilmette   |  last reply

Comber greenway opening.

Saturday 8th November the Comber greenway will be officially opened in Belfast, which is kind of odd I've been riding it for nearly a year since they paved it and a few years when it was an assortment of dirt tracks and swamps. A Community Carnival cycle to celebrate the opening of the Comber Greenway has been organised on Saturday 8th November starting at 9:30am at Walkway Community Centre, Finvoy Street, East Belfast. Full details of the days activities are available below.Carnival program9.30am - Welcome and Wobble Activities at Walkway.Porridge for Pedal Power!Tree PlantingBicycle Obstacle RaceSlow Bike Race10.30am - Ribbon Cutting Ceremony: The Comber Greenway is Open.Community Carnival Cycle to Comber with Paddy Bloomer artist, inventor, explorer and plumber the most exciting mobile spectacle since Mickey Marley's roundabout!Tullycarnet Tuck Stop12.45pm - Eats at the Enler River (provided)1.15pm - Carnival Cycle Continues2.00pm - Pedal Parade into Comber - Refreshments2.45pm - Homewards for the Holywood Arches to arrive by 4:30pmChildren under 16 must be accompanied by an adult and wear a helmet. Information taken from information on the greenway at Comber greenway.tkI'll have updates on this and more late saturday or sunday, it's a big thing for many cyclists and I here in Northern Ireland since it's been threatened by a high speed bus route, the track used to be a railway and it's a lovely ride, though calmer than my usual...

Topic by killerjackalope 

do you log in as amninistrator ?

I am linux (arch linux) user so the question is aimed mostly at linux users. but i'd like to see what windows and other os users think toowe all need sometimes to log in to the computer as administrator (called root in linux) to do maintenance and other tasksin modern os we have some options. we can log in to the entire desktop or console as administrator and work freely. or we can run the single apps we need with 'run as administrator' from our user desktop. maybe we work all the time as administrators (even to surf the net) and then there is no question at allin the world of linux many users dont recommend logging it to the desktop as administrator. i dont understand why. i think based on the following assumptionsi am less likely to smash something when i see it. so i prefer to do stuff in the desktop and not in the consoleif i smash the os i can just format and install it again quickly. if i smash any of my files in home (home is like my documents in windows) i can never recover it again. and i have permission to smash my files when i am normal user tooi trust my applications to not format my drive on their own decisioni log in as administrator to the desktop when i need to manage and as user in other timeswhat way of getting administrator access you use ? why ?

Topic by 11010010110   |  last reply

How to make cuts for a child's jigsaw Answered

Greetings from a new Instructabler: I'd like to make some wooden blocks as well as some jigsaw puzzles and perhaps a lockbox for my daughter.  (She's six months old now so I have some time to figure this out.)  I'm thinking something like this for the puzzle (simple shapes and pegs for her to grab onto), and something like this for the lockbox.   I'm trying to figure out what is the fewest number of saws I have to buy to make all these things.  Seems like I'm going to need a band saw for the wooden blocks, but I'm wondering if I might be able to get away with it on the scroll saw?  This extremely helpful site describes using a band saw with a circle cutting attachment for arches and triangles.  Do I need a band saw for cutting 2 3/4" hard maple?  I'd likely have to just not make the 5 1/2" triangles if I went this route (which wouldn't be the end of the world). I'm a bit puzzled (as it were) regarding how to make the puzzle pieces and also the doors for the lockbox.  I imagine that if I didn't need the puzzle piece itself and just needed the outline then I could drill a hole in the piece, thread the scroll saw blade through, and cut the shape.  How do I make the cut that preserves both the puzzle piece and the surrounding wood?  Do companies that make these toys make the puzzle pieces (and doors) separate from the puzzle outlines (and lockboxes), or do they use lasers or something else? Your guidance would be greatly appreciated!

Question by statestraveller   |  last reply

Is it possible to use a DVD player hardware / peripherals and convert it into a small "net book" style computer?

I have a "older" (maybe 2 years tops) DVD player made by Haier with a 7" screen. (Total width is about 8 inches.) My questions are numerous but can be sumeerized with this: Can I use the case, psu(battery), and LCD and rip the rest of the guts ot to make a small computer. Now granted, I know it won't be any kind of speed demon. I have built many desktop systems before. But insofar as laptop hardware is concerned I might as well call myself a complete beginner. My plan is thus (and if you would like pictures of the existing hardware and connectors I would be able to supply them): I would take out the mobo and the drive which is broken (my daughter burned the motor out when she was younger by manually moving it) and try to replace it with a smaller form factor motherboard. I would need this mobo to be able to boot from a usb drive so that I could use a bootable linux, possibly ubuntu, and maybe another usb drive for an input device. (Mouse most likely, use an on screen keyboard.) Another question would be are the connectors for the i/o in small devices standard or are they mostly proprietary? Would I be able to use the existing cables with a motherboard? If not are there converters? And the next thing would be that I would need a network card to work with it.... In the end, I would like it to be able to use a tiny linux, have some sort of i86 architechture (becuase flash 9 or 10 wont work with a powerpc arch.), and be able to use firefox to view youtube. It's kind of a gift for my daughter. Is it possible?

Question by Asmodean_7   |  last reply

soft LED screen

Soft LED display is our Patent product(Chinese National Patent), as is shown that the screen can be folded, curved and transformed, it can be applied any shape, like circle, arch, or even right-angle. Most importantly, it is light-weighted and easy installation, one square meter just weight about 5 kgs, and the whole system can be hung on the truss or on the building. And it can be expanded through connecting several pieces of soft LED display together to make a larger screen as you want. Through one and a half years developing, we make immense improvement and solve all important problem. We use the cloth processed specially, so it is waterproof completely, fire retardant and strong enough. (although the both sides is all waterproof, we sign it IP44, because we do not recommend our customer to use the screen in the open air all the time.) We develop this kind of product mainly applying to stage, TV studio, concert, night bar and disco hall. Attached a small video and some picture, please check it, through video and picture you can find the characteristic of our soft LED screen. We are eagerly hoping that we can cooperate with your distinguished coperation,and hope that our product can satisfy you with its light-weight, easy installation,foldability and flexibility, I think it is your best choice.Contact info: Fisher(sales manager) Beijing Huasun Optoelectronic Science Co., Ltd Add: Yongshun Town, Tongzhou District, Beijing, P.R.China Tel:+86 10 89512349 Fax: +86 10-89512339 mobile : 0086+13146411249 E-mail: skype: fisher201223

Topic by yuchao622 

(newsletter) Nintendo MP3 Player, Paint with Light, Zen Art...

Jan 15, 2009 Sign-up for this newsletter: function openSubscribePopUp(src){ var emailValidate = /\w{1,}[@][\w\-]{1,}([.]([\w\-]{1,})){1,3}$/ if(emailValidate.test(src.value) == false){ alert("Please enter correct email"); return; }"/newsletter/newslettersignup?email=" + src.value,"newslettersignup1","status=yes,scrollbars=yes,resizable=yes,width=420,height=250"); } Welcome back!It's cold here in the northern hemisphere! (OK, it's 70F here in SF, but Robot is still knitting another scarf - best to be prepared.) Regardless of your climate, show us some great ways to fight the chill in the Stay Warm Contest, and win a sleeping bag!Reuse and recycle! Show off a clever reuse for a plastic bottle in the Tap'dNY Keep the Bottle Contest and win a Voltaic solar-charging backpack!The Craftsman Workshop of the Future Contest finalists are up! See all the entries who are moving on to Round 2 here! The winners of the Homemade Holidays: Holiday Gifts Contest have been announced! See who won! Fast Foam Lathe by marc.cryan Duct Tape Guide by lukethebook333 Open Manufacturing How to Build 30 Kits by Stuart.Mcfarlan Make Your Leather Boots Last Forever by ehmbee View the finalists! Win a Voltaic solar-charging backpack! Make an Art Bowl from a Plastic Bottle by gulguvenc Snow Arch by AndrewM Make Simple PVC Flutes by Jnkyrdguy Paint with Light by CYNICALifornia Cheap Car Underbody Lights by zerox61 Zen Art With A Water Bottle by domestic_engineer Lined Messenger Bag by cwickham Giant Fake Vacuum Tube by DirkGently Share your best way to fight the cold and win a sleeping bag! See who won! ReUse ReMake Crayons by SomArtMama Pirate Treasure from Trash by 1gruviscrapper Nintendo Controller MP3 Player by ryan97128 Pill Bottle Lamp by wholman Now go make something awesome, and I'll see you next week! - Eric Sign-up for this newsletter: function openSubscribePopUp(src){ var emailValidate = /\w{1,}[@][\w\-]{1,}([.]([\w\-]{1,})){1,3}$/ if(emailValidate.test(src.value) == false){ alert("Please enter correct email"); return; }"/newsletter/newslettersignup?email=" + src.value,"newslettersignup2","status=yes,scrollbars=yes,resizable=yes,width=420,height=250"); }

Topic by fungus amungus   |  last reply

Where to get piezo igniters?

I have several lighters that I still like, either for their design or intended purpose. But over the years some failed to produce proper sparks with the piezo. For some I could salvage replacements from cheap lighters but not so much for the longer ones - the type to get your bbq or oven going. Here the wire from the igniter is in ne long piece going all the way from the piezo, through the long neck to the flame outlet. As the wires in those piezo igniters are aluminium it is next to impossible to attach a longer wire as usually there is no room for crimped connections and the isolation is a problem too. I also have one particular lighter that uses a slightly longer and thicker piezo igniter, the common ones don't work here as they are too short. Adding more support underneath is a no go as the shorter ones have less travel when activated. Last but not least is one lighter that requires a piezo with not just the little metal cap at the end but with a full metal body for the stationary part. The lighter in question does not work with standard types even if I add a little metal strip to make proper contact. Problem is simply put that like this the standard ones arch over and no spark comes out of the wire. So big question: Is there any supplier or Ebay shop where one could actuall see the various types of piezo igniters and order them in small or single quantities? So far I already struggled to find a source for the crappy standard ones and the only one I found wanted to charge $ 2.95 US per igniter plus postage. Sounded a bit greedy to me considering I can buy a complete lighter with it for around one single buck...

Question by Downunder35m   |  last reply

First project, Need help with materials selection :)

Hey everyone! This is my first post here and I hope someone can give me a hand, or I can contribute in the future.  For now I need some expert opinions.  For a project in school me and my partner came up with the idea of making our own air filtering baby canopy.  I made a drawing of what I imagine it would look like.  I just for the life of me can't come up with an idea to make the frame out of. Here's an image so you can see what I'm talking about... (side) (top) So I'm pretty sure I can make the base and the supporting frame out of 1/2inch PVC pipe with 45degree elbows.  The electrical and fan for the filtration unit and netting we have have sorted out already. For the life of me, I cannot figure out what to make the "filtration unit" out of.  It needs to be a shell basically so I can fit the filter and fan inside.  First I thought maybe use thin aluminum sheet metal and form it to a desired shape.  (I've even found stuff for air conditioning ducts that is almost in the shape and size where it would work for a prototype.  I even had an idea of using foam.  Use a foam cutting tool to make a top and bottom piece, paint them with an acrylic coating to harden it.  Then gluing the top and bottom piece. *Any idea what I can use to make some sort of "box" that doesn't look like junk to hold my internals? Also, taking any ideas of how I can make the folding joint for the supporting arches.  I was thinking maybe just making them less wide than the frame, so they can be lined up towards the center, and drill a hole through them and bolt them.  Any comments? If you've made it this far in my post, thank you!  And I look forward to any of your craft ideas. tl:dr; What material can I use to make a "shell" of a desired shape that can hold electronics and stuff? -Mike

Topic by de312   |  last reply

Born to Run the Oakland Marathon

On Sunday, I ran the Oakland Marathon, finishing in 3:54:29, and placing 215th out of 945 runners.  I know it's cliche, but I read Born to Run and got inspired me to run a marathon.  It's the best book I've read in years:  the characters (all real people!) are fascinating, the setting and story are fantastic, and it just made me want to get out and go.  Halfway through the book, I decided to run a few miles to the grocery store in the rain just to run out back, not because I needed anything. Prior to reading Born to Run, I had been running a 2-3 miles twice a week to vary my preferred morning exercise routine of biking or swimming (the kitesurfing season hasn't really started yet).  Running was something I did if I couldn't get to a pool or didn't have the time for a long enough bike ride; it was exercise I did while traveling and when there were no better options.  Born to Run made me question that assumption, and I decided to see how longer runs would feel. Over a year ago I read "You Walk Wrong", a New York Magazine article on going barefoot.  It convinced me that I should be able to go unshod, or at least with minimally foot coverings.  Why would 30 years of running shoe development be able to produce better results than millions of years of foot evolution?  So I bought some Vibram Five Fingers  to protect my delicate soles, and had been doing lots of hiking and a bit of running.  The difference between running in running shoes and Vibram Five Fingers was profound for me.  In running shoes, I typically stopped running because my knees and hips hurt, not because I was exhausted.  The Vibrams forced me to take smaller, faster strides without heel strikes, and suddenly I was getting closer and closer to being able to run long enough to catch exhaustion without any joint pain.  The concept of going barefoot was initially tough because of my flat feet and overpronation, and the possibility of re-dislocating a kneecap. I never went anywhere barefoot, and after I initially dislocated my kneecap in 2000, I was told by a sports medicine doctor that I should never walk without the aid of custom orthotics in my shoes.  However, barefoot websites and forums are full of stories about people's arches coming back, and how kids raised without shoes never have flat feet.  Amazingly, it's all worked perfectly for me.  I now run without my orthotics without any knee pain, and my arches appear to have (re?)formed.  After hopping out of the pool, I always inspect my wet footprints, and they now have distinct arches.  I wish I had taken photographs every day to plot progress. With the characters and race in Born to Run still fresh in my mind, I looked for nearby races to give myself some motivation and something to train for.  When I discovered that Oakland was holding its first marathon in 25 years, and that the route literally went through my neighborhood, I immediately signed up for the half-marathon and convinced Christy to do the same.  I researched training regiments online, and discovered many were 4 and 5 month plans; since I had 50 days before the race, I decided simply to run longer and longer distances at a comfortable pace, and not worry about a rigid structure.  I ran most of my miles on trails in the Oakland hills, and some on the streets, but all of them in my Vibrams.  During a practice run on the half-marathon course three weeks before the race, I completed the half in less than my target time for two hours and felt so good that I opted to do the full marathon. In the marathon, I ran with GEICO-sponsored pacers aiming for a 3:50:00 time (8:46 miles on the flats, and slower miles in the hills; course elevation PDF here).  Of the three pacers, one was running his 34th marathon, and the other two were ultra-marathoners training for a 200 mile race from Calistoga to Santa Cruz; their normal weekend run was 50 miles, so a marathon was like taking a break.  Running in a group is awesome and way better than running by myself listening to audio books.  On multiple occasions, I imagined that we were the hunters of a tribe out running down game -- water stations every couple of miles broke the illusion, but I still eagerly grabbed cups, and the community support was tremendous.  There were bands, drummers, DJs, and gospel choirs making music along the route; families with full brunch buffets setup in their front yards offering all the runners fresh fruit and homemade baked goods; and many people just thanking us for running in Oakland.  The second image shows all my runs in the 50 days leading up to the marathon.  The first 5-mile run on the chart was the longest I had ever run at that point.  While I was coming from something of a limited endurance background (I've biked 135 miles on a tandem from Boston to Provincetown in a single day), I didn't really know my limit.  At mile 23 of the marathon, I finally caught up to exhaustion, and fell behind the pace group.  The last three miles were painful, but in the last quarter mile, I couldn't stop grinning and felt like I might laugh and cry at the same time.  When it was over, I just wanted to sit down. I was aiming for a sub-4-hour marathon, and I'm really proud to have done that on my first try.  Everyone made fun of me for walking like a zombie the next day at work, and I have some pretty large blood blisters on my feet, but nothing that won't disappear in under a week.  Go and read Born to Run, it might inspire you, too. Christy says: I'd always had to run as cross-training for other sports (I swam competitively for 13 years) and ran when I needed quick exercise, but hated it - my joints hurt, and it just wasn't fun.  I was a distance swimmer and can hike nearly forever, but could literally swim farther than I could (or would) run.  The most I'd ever run before was about 4 miles.   I got my Vibrams with Eric, and really enjoyed hiking with them on my feet.  I hadn't run in nearly a year and a half (pregnancy loosens the joints, which made running feel even worse) so when Eric announced he was signing up to run 13 miles I was dubious.  However, I read Born to Run and was suitably inspired - I was in good cardio shape from swimming and stationary biking, and would happily hike 13 miles, so why couldn't I run that far?  I decided to go out for a 5k jog to see what running felt like in my Vibrams. Long story short, I accidentally ran 6 miles, stopping not due to fatigue or joint injury but because of a blister from a poorly-adjusted shoe strap.  I signed up for the half marathon that evening, and started taking increasingly pleasant runs through the parks and across the city.  I ran the half-marathon course with Corvidae in her jog stroller, stopping to feed her periodically.  Eric finished while I was on mile 8, so he backtracked along the course and met us at mile 10, by which time she was thoroughly done with this stroller nonsense and had migrated to the sling.  I left the two of them to their own devices and jogged the rest of the way to the finish, about 3:25 after I started in the morning.  Not terribly speedy, even given the breaks!  The next day the bottoms of my feet were sore, and one of my Achilles tendons was a bit inflamed - I'd describe it as having overused my springs - but even though I was limping, my muscles were still in good shape. My pace is still quite slow (I ran the half-marathon in 2:42, for roughly 12:26 mile splits) but it's frighteningly consistent - I negative split most of the race, and at the end discovered I still had plenty of energy to sprint past a dozen exhausted runners.  Clearly I didn't run fast enough or far enough, but I was specifically setting a pace I felt able to maintain indefinitely.  The weak link is still my feet!  While I had plenty of muscle and energy left at the end of the race, the bottoms of my feet were tired from use - more practice is necessary to balance out years of shoe-wearing.  However, I recovered much more quickly this time, and was able to run again by Tuesday morning.  No zombie shuffle for me!  Of course, this means next time I'll be running the marathon, and at a faster pace!

Topic by ewilhelm   |  last reply

whats next (updated)

Ok i bough this knex lot on for $42 and it comes with tons of stuff and below is what it has from the bid. take a look.This weighs OVER 20 pounds and we stored them in a Almost full, 64 quart Rubbermaid container (not included) LOTS AND LOTS!! Some of the pieces included are from rare and older sets, some of the pieces/sets are from the early 1990's.In the pictures is a 2 liter of soda, for size reference, not included.One picture is of the lot together, one is of the instructions included from front and top to see thickness, and one is of the motors and zip pull car included.There are 3 motors included in this lot; *one is a big alien(?) head, that i don't know what it is or what its from, but its a blue head & a big black power box & 2 additional motors that are all attached to the head with wires. I am unsure if this works, (untested) because i don't know what it is supposed to do, it does take batteries and as far as i can tell, it does not use a power cord. *One large grey one, takes batteries and does work, it measures about 6 inches long, 2 inches wide, 2 1/2 inches tall and goes forward and reverse and slow and fast, this come with batteries in it and can be used for ANYTHING! Cars, farris wheel, swings, anything your little ones hands can make!*another motor is the motor that came with the Farris wheel and/or roller coaster set, one of those, it is untested because the power cord box is missing from it, but it is a typical power box plug that is needed. worked last time my kids built a farris wheel ;0)Several WheelsI did not go through and inventory them all, because there are alot! But it does appear that they are all in pairs. There are 4 BIG monster truck wheels with rims (complete set) and there are medium wheels and small wheels that all share the same rims, there are also skinny wheels for like dragster type or motorcycle vehicals. and more!A zip-pull racer car, speedster!One red zip-pull racer car body, with pull, used for building a car or racer around and then insert the zip pull above the wheel and when you pull it out really fast the car takes off!!! No batteries required and it works!! (And there are instructions for this in here also.)Lots of gears! Lots of sticks in various colors and sizes!Lots of plugs and rings, or end pieces for stabalizing and holdingSeveral fans or flat pieces, (i.e. for a windmill or spoiler on cars etc)A few bendable pieces to make arches and turns2 bodies for making peopleSeveral caps and tops and 'balls' for building different thingsRubber bands for Racers and gears (instructions included)Instructions are for;(instructions are not in the best conditions, some have been ripped and taped back together, and some are missing small corner pieces, and have folds in them, but they are not missing pages as far as i can tell)*Rubber Band Racers (no model number on booklet)*Breakaway Speedsters 11524/21524*Street scorchers 11127*Safari Fun Set 11558/69815*Intermediate set 50015 and some loose various pages that may have been from another book/set that was simular or more advanced are inside this book also.*4X speedsters 3 10315/69948*Knex motor pack instructions for use (for the motor that is missing the AC adapter, says it uses input 120 volts AC 60Hz 12 watts, output 12 volts DC 500 mA adapter.) and there is a costumer service number on it to order replacments, so that may still be available.*Zoo 10 models building set 31009*Vehicles 10 models building set 31008*All terrain trekker builds 3 models set (uses the big gray battery motor) 13501/23505*Roller Coaster instructions Loop Version 63030 (I do not recall us having this roller coaster set and did not see any 'rail' pieces in this mess of Knex, but I did see some 'chain' pieces and gears, most of the set looks like the normal pieces, with exception of the top rails.)*AND also some advertising booklets that came with the sets that show additonal sets, the kids kept them and would use them to copy the pictures and build from them.*I do Not have instructions for that big head thing...I really do not know where we got it...??? But it is K'nex brand.All the instructions included are Awesome to have, because thats what usally gets lost, However, this lot does not included all the sets i have instructions for, and the ones I do have are probably not complete. Most of the instructions though can be used with any Knex pieces, I am just saying if you seperated them all out according to the instructions you will not have complete sets, and some pieces may not be there at all. These are used and were loved by my boys and some pieces were mine when I was younger and are 18+years old. I did not notice any broken pieces left in this lot, but there are A LOT of knex so there may be some, the few I did noticed i took out and threw away.but i was wornding what should i bulid but im make a listmakeing:ossr by dj radiocirle ball machine by iacscar11.01 and morriti and Park 52 knex sniper by the burrito masteriac's knex heavy cannonbox,nano,duex by darth trainmancrank by smileedos,project n,uno by the jamalamLithium by the knex weaslemicro by cfcubedthis is not well know so it has link Ultimate Simplicity 1: relentless,Project 2: Aggresor by tombuckeyThe Storm 223 V1.3 knex gunKnex Tavor TAR-21 by maxxium

Topic by knexsuperbuilderfreak   |  last reply

TV antennas and what is possible indoors

Back in my young years a TV antenna was on the roof, quite big and only required to get 3 or 4 channels at best.The basic design of these Yagi antennas has not really changed since then.Same for the antennas required to get UHF and VHF channels at the same time.They either comes as two seperate antennas with a mixer or as a UHF antenna with some added loops for UHF.To talk some basics:For UHF you can get away with quite small dimensions for your antenna bits.After all a quarter wavelengths here is only around 15cm long.With VHF though we get already 30 to 40cm here depending on the channels.So called bradband antennas claim to be able to get a wide range of frequencies.That however is only true for their dedicated frequency band.If you take a normal whip style antenna then this becomes obvious - just compare the lenghts required and you realise "going the middle way" will mean neither UHF nor VHF would get any usable reception.For a long time now there is the option of so called "fractal antennas" to get better TV reception....Fractal antenna? What the heck is that?The theories behind them are about as old as fractal antenna designs that were not even considered to be fractals.Let me explain with the example of a standard FM radio antenna.For them we use frequencies from about 88 to 108MHz.And of course, for our cars they are always on the roof or mounted somewhere around the wheel arches.Some cars however does not seem to have any antenna depsite having a working radio.In this special case rest ensured they do have one, usually behind the plastic bumper bar ;)I like to go off road every now and then and lost count how many times I had to replace my antenna after getting to close to some bushes and trees.As a solution I used some thin wire to create a L-style anteanna on the inside of my windscreen.And funny enough it picks up more stations than a "proper" antenna outside.Really old design and if you think about it then an antenna with a kink that looks like L is ""self similar" - the definition of a fractal ;)More complex shapes like the Sierpinski models do exactly the same just in one more dimension.Cell phones use them as well as you WiFi router that has no external antenna anymore.Their designs and looks are so different that it is next to impossible to list the currently used shapes here.What it comes down to, when you just take a very basic flat or wire shape is that the straight single segment of the active antenna is split into one or many shorter segments that change the angle.They all have similar relations to the wavelenght still.Means really long segments might be half of a wavelength while the shortest bits are just 1/64 of a wavelength.Think of it (far too simple of course) like amny matched antennas combined into a single one.With that often comes a destinct radiation pattern, usually with a quite narrow beam angle that provides a quite high gain.Are fractal antennas any better than for example a proper Yagi antenna?You can ask 100 people and you get 100 different opinions for this one.This is mostly due to some simple facts like:Not caring about actual comparisons.Not being accurate enough when building the fractal antenna.Using just very basic equippment to compare results.For example when you have a 30 year old and quite small TV antenna on your roof and struggle with digital TV reception than you might want to just replace it all.In some case even the old rabbit ears on your TV set will work better.But take modern Yagi antenna with 12 or more segments and even station that are 100 miles away have a good chance.Comes down to possible gain, frequency match and of course how well the antenna is aimed at the transmitter.Then why is it that some fractal antennas still seem to perform so much better?The big antenna scam....If you paid attention during the intial DVB-T rollout in your country then noticed two things.a) You were told you need a TV or set top box capable of receiving DVB-T signals.b) You need a suitable antenna.Well, A is obvious but for B a lot of people got scammed badly.You see, in almost all cases the frequencies allocated for TV signal did not change at all.And an antenna really does not care if the incoming signal is analog or digital - it only cares about the frequency.But more and more local stations often meant that the trnsmit power is limited.After all it makes no sense to have a 500kW transmitter if the area to cover is only about 20 square km big.So people were told they need new antennas once the noticed digital TV is more like playing Tetris, blocks everywhere....You analog TV had no problem with a slightly weak signal, you did not really notice it unless the weather was really bad as well.All the benefits of digital TV however only work with a proper signal strength.If your areas still has both analog and digital TV channels then have a look on how your local transmitter provides the signals ;)Part of the big scam was hiding a very simple fact:All analog TV is transmitted in a horizontal orientation while almost all digital TV is transmitted in a VERTICAL orientation.Ok, we already gain and ignored it but why would the orientation be important?Your radio antenna is vertical because the FM signal is transmitted the same way - the "waves" if you like go up and down like a sine wave.You still get reception if you turn the antenna 90° to make it a horizontal one but you will realise that weak station are no longer available.The same happened with digital TV.And if there is only digital TV left in your area then simple turning your antenna 90 on the mast to have the single elements vertical instead of horizontal gives you top reception again ;)If you struggle to get all station then just try it out before buying a new antenna ;)Modern fractal TV antennas come paper thin and often with rediculous claims in terms of gain and range.On Fleabuy you can even find models claiming to get stations from over 2000 miles away LOLSome even come with the fake claim of being omnidirectional, meaning it does not matter where you place them or how you orient them.A fractal antenna can't change basic phsyics though...High gain mean highly directional or at least with a very flat radiation pattern instead of being more like a sphere.A high bandwidth means you compromise on the gain and/or the phsical dimensions.For example a thin whip antenna is quite limited in the optimum bandwidth while a piece of tubing provides amuch higher bandwidth but at the expense of gain (and some other problems).A fractal antenna can compromise between the two worlds much better than anything straight.And you would even need to make the traces on the plastic extremely wide because you can simply add different lengths for different frequencies.Means a wideband fractal antenna for FM, VHF and UHF basically is three different antennas combined into a single one.It also means that there is usually always more than just one single element of the antenna that is receiving a signal.If you experimented with WiFi antennas for your router or modem than you certainly found the famous Pringles can antenna - highly directional and with an insane amount of gain.Works exactly like a simple directional microphone.And you could, at least in theory do the same with a TV antenna - if there wouldn't be the problem of the wavelenght.A pringles can works for WiFi because the wavelenght only requires an antenna of about 3cm in lenght.You might not want a row of steel drums with a diameter of around 80cm on your roof just to watch the news though...Ok, if I need a new antenna anyway then should I get a fractal antenna or not?I try to make it simple:Roof option not possible or too costly AND your transmitter is not too far away then try one of the cheap paper thin antennas you find online.If you already have an antenna on the roof that is suitable for the frequencies you need then check it to know if it is still any good.With age and weather comes corrosion and some antennas are connected badly in this regard.Sometimes you are lucky and all it takes is to cut off a few cm of cable to get back to clean copper and to give the terminals on the antenna a good fine sanding or a wire brush treatment.In other cases you might find an amplifier under the roof that has faulty power supply ;)And well, certain animals love to chew through your cable...If all is goo from antenna to TV then as said try to flip the antenna 90° to get it vertical.No, I did not mean to point it up to the sky..... ;)I mean rotate it around the x-axis if X is pointing in the direction of the transmitter...

Topic by Downunder35m 

Very old shielding materials and techniques for permanent magnets and resulting possibilities

Forromagnetic meterials are not just called that for no reason.It comes from ferrous - iron.Iron has the highest permeability at normal temperatures.That means a magnet is attracted to it very strongly.We utilise this for transformer cores, the stuff inside a relay and the moving latch of the relay itself.Like current from an electrical system magnetic fields like to take the easiest route possible.Air is a very bad medium, so any iron close by will be prefered even if it is at a slight distance.You can check with a magnet, a steel bar and some iron shavings - please cover the are with plate first ;)Slightly less known is the option to also guide and extend the magnetic field this way.If you check how far the magnetic field of a magnet reaches and note that distance,then you can add some steel bars or rods at the poles - the field will extend through the metal.The most powerful example of this are the shielded magnets used for hooks or speakers.Except for a tiny area the entire magnetic flux goes through the metal.So in this lefover area the magnetic flux density will my many times greater than what the magnet alone would be able to.What most people don't know is that magnets also interact with other magnets in terms of their fields changing and distorting.The Halbach Array is a good example of this.Seen as a single magnet the array would have one weak and one strong side instead of even strenght for both.Wherever magnetic fields change a conductor can produce electricity or current.This in return causes an electromagnetic field that opposes the one from the magnets.Just drop a magnet through a copper or aluminium pipe ;)Since these distortions are widely unknow to the hobby tinkerer mistakes can happen ;)In the early days of exploring science some people already knew about shielding.And they also knew that certain metals have certain properties.Where it is quite hard to create a good coil from steel wire, copper works fine as it is not magnetic.What would then a copper shielding do?If you have two moving magnets with only a tiny gap then the resulting field distortions are quite huge.A copper shield around the magnet like a pipe would then react to these changes and also create a megnetic field that works in relation to the enclosed magnet.In simple terms it means the shield would let the magnet appear weaker or stronger depending on the field change.A quite old document I found gave some hints on how people thought in different directions back then.It was in regards to the design of a magnet motor by the way.Here various magnets were shielded in tube made of a copper-bismuth-alumium alloy.These tubes were then electrically connected so it created a single loop conductor.The claim was that the resulting electromagnetic field of this ring would drive the fields of the enclosed magnets sideways out of alignment.Like bending straight pastic tubes sideways.This "pulsating" would always happen when the magnetic binding forces reach max and so basically drastically weaken this binding effect.Another document talks about a "magnetised brass rod".A holes of the rod diameter is drilled through a block magnet.Not from north to south but through the middle where the flux is greatest.The claim here was that if that rod rotates fast enough a very low voltage with a very high current will be generated.Sounds easy and interesting enough that I might have to test one myself one day.The best one however is what I consider a hoax or being as good as Starlite.Someone back in 1908 claimed to have created a material the reflects magnetic fields.In lame man's terms it would be like an insulator around some electrical wire.The claim and some pics showed it, was that no magnetic field can pass the material.Or to be correct only a tiny fraction of what would be possible through air.A small magnet inside a longer tube of this material would create almost the same attraction to steel at the tubes ends as on the magnet itself.Measurements showed the field strength would be almost equal to a long mangnet of the same field strength.Imagine guiding the field of a big and powerful magnet through a tube around some corners or other magnets and then end in just a tiny hole for the entire flux...Too bad he never shared his secret formula to anyone knows to mankind.Isolation...Imagine you have an array of changing magnetic fields and quite strong magnets.Then you might face the problem that your focus on the "working" end neglected the other end of the magnet (stack).Providing some iron core material will keep thes field lines contained and away from interfering with your setup ;)But it also allows to use te otherwise unused end of your magnets more directly.For example by guiding to another magnet to affect its field strenght ;)Placing a sheet or steel between two magnets in a setup provides a "shared pole" so to say.If you have a north and south pole on a rotor at a distance of 5mm then a sheet of steel between will drastically weaken the strenght and reach of this combined field.It is like pulling the arch between the magnets down to make it more flat.And at and an angle the resulting field will also be slightly angled ;)Capping...When I first encounter this many years ago I couldn't really make sense of it.Quite complex..If you check the magnetic field lines with iron filings or similar then you notice how they go in a rounded manner from pole to pole.This is because the single field lines are of equal polarity and will dirve apart like opposing magnets.By capping the ends of a magnet you provide a short.Instead of diverting out like mad they will follow the cap and create very intersting magnetic field in return.If both poles are capped it is like pressing the magnet flat but without having a field on top of the oles - only aorund the center part.For this the thickness much must match what is required for the flux density.As a rule of thumb: if the end is still very magnetic then it is not enough material tickness ;)Interacting fields in a tube...This one is quite old too and seemed to have found no usable inventions apart from simple magnetic spring replacement systems.But it gave me some clues about Tesla "earthquake machine" ;)If you place a magnet in a tube and at it's ends magnets with opposing fields to the one inside then you can fix this magnet in place.Push one magnet deeper and the distance from the inner magnet to the other end will shrink the same amount.In this old paper two coils were around the pipe with the inner magnet between them.In this gap and at about the same width as the magnets length another coil was placed.Violent shaking would then create electrical energy at much higher level then modern shaker torches.In return an AC current on the outer coils would cause the inner magnet to move back and forth to create electricity in the center coil.According to the paper possible uses include: core less transformer, measuring minute changes in AC voltages, providing free power from a running motor...The last one had me stumbled for a very long time.Until I considered a different configuration.The whole thing is basically a linear DC motor - with correct timing of course.And in some motors we use permanent magnets.I am starting to wonder what would happen if we would design a rotor magnet like this?The running motor would be subject to constant field changes that affect the rotor.And a normal motor is always "even".By using four magnets instead of one we can push the field really flat.This means the area where the coil would operate (about 1/5 of the magnets area) will have a much stronger field.The resulting torque should be higher by about 25% !!Even a simple two coil model setup should show a significant increase in performance here.Timing is critical here but I tried some calculations based on 8 poles and the required "on times" for the coils.In a standard motor configuration with a single rotor magnet the coil is active for about 12° of the rotation.With a 4 magnet configuration this "on time" can be reduced to under 8° of the rotation to get the same amount of torque.An energy reduction of about 4% if you neglect losses and only think in time.If you think in terms like impulse energy then we are talking of about 15% !Shorter on time but still much higher flux density overall than for the long standard timings.Going the long run now:If you check how most DC motors work then you realise soon that for most one rule seems to followed.Only use one coild pair at a time.This is quite contradictive if you consider the geometry and options.A dual commutator would allow to use a second coil pair with a field OPPOSING the magnets instead of being attracted to it.After all: on you bike you pedal with both legs and not just one...And if you do it professionally then yu do the same as I suggested for the motor - you use the up pull of your legs as well.Doing it brushless only requires amodified h-bridge desing to drive the second coil pair at the right timing.Some will now say that it requires twice the energy, I say that for the same motor size your get twice the torque!Just imagine what that means in possible weight reduction for a motor - or its size to deliver the same torque at the same power levels when a normal motor is used ;)The more poles the more complicate the precise timing but no big deal really with modern electronics.Can it be improved even further?I though long and hard about that one until I considered EMF.A DC motor produces a lot of it when the elecromagnetic field collapses in the the coils.We do not utilise this energy...There is a tiny delay until the released energy levels are at max.My theory is that it should be possible to divert this energy into another coil set.If that coil is not the next active but still within a strong enough field area then the EMF would actually add to the drive of the motor.Only downside is that according to my calculations at least 16 poles would be required to get an optimum result.Way above of what I can create in my little garage :(In theory it should then be possible to reach about 98% efficiency for the motor....

Topic by Downunder35m   |  last reply