Calculate bending moment of a beam and the size of the beam to be used? Answered

Please refer to the uploaded images. (there are two images) When the right of the weight is lifted up, I need to know the formula to calculate the bending moment of the beam according to the rest of parts I have and how to calculate the suitable size of the beam to be used. I appreciate your help very much...

Asked by seankoh 9 years ago

When was the BristleBot invented? Answered

Was the BristleBot invented by Doug Stillinger, Evil Mad Scientist Labs, Ben Jaques' friend, all of them, or someone else entirely?

Asked by NobodyInParticular 9 years ago

Visible Laser Beam

Hello, Without going into too much detail, a friend and I need to build at least four visible laser beam systems. We were looking on Amazon for visible green lasers but the reviews were so so. We are looking for something that could last for at least an hour and a beam that can be bounced off of multiple mirrors. Thanks

Posted by RipDiesel22 7 years ago

Infrared Beam Burglar Alarm

Could someone please tell or show me a fairly inexpensive way to throw an infrared beam across my office and once it's tripped by an intruder an outside alarm or siren (I mean the loud ones-like you can hear several blocks away)would go off. I'm so impressed by the quality of minds on this website. I know someone can probably help. Bless You All.Thank You So Far!

Posted by ropor 10 years ago

Using lenses to create a beam of normal light??

If you had, say, light from a torch or whatever, directed it through a metal pipe or fiber optic to get it kind of directional, and then into some arrangement of lenses; what kind of maximum range could you expect before it completely lost focus? And would it still obey the inverse square law, or is that just for expanding spheres of light?

Posted by SolarFlower_org 9 years ago

High-Tech Peashooters with laser beams!

In this peashooter competition in the UK, some entrants have modified their basic tubes with some high-tech parts. This one uses a laser sight and a gyroscope to help aim. All of this is fine with the organizers who have allowed laser sights for a decade.Even so, the winner this year was someone with a regular peashooter so it still is quite a bit about skill. Pea shooters fight it out for world championships via BoingBoing

Posted by fungus amungus 8 years ago

My new Symet (BEAMbot)

Hi everybody.Just wanted to share a video of my second Symet BEAMbot.Here it is: Hope you like it.**********UPDATE************Watch his new talent: _lowercase

Posted by lowercase 9 years ago

Suggestions for simple recycled electronics project?

Hi folks, So I'm putting together a workshop for primary schools kids on making things with recycled electronics. I'm trying to think of a circuit which each child could reliably get the pieces to make (I have a big pool of bits, and we'll be asking them to bring in stuff) - so the bits I reckon we'll get a lot of are resistors, capacitors, switches, little motors and LEDs. Can anyone think of something simple you could make out of those that might be fun to have at the end - some kind of simple moving bot or some such? I've done some of this kind of stuff myself, but my electronics knowledge isn't hot enough to figure something out by myself... Thanks! Brian

Posted by towelinmonk 6 years ago

LED to laser beam?

I have just started the optics section of my physics class and I was amazed to learn that one can use a simple magnifying glass to form a beam from an LED.  Could this be used with a high power LED such as a 100 watt one, and then a beam expander (backwards to compress it) to form a laser beam of sorts.  Obviously it wouldn't have a common frequency, but could one theoretically make a very high power, burning beam with this quite easily. I know from experience that holding your finger in front of a mere 10w led can get quite hot, so couldn't using a 100 watt led yield some awesome ant killing hotdog frying results?  If not, how many beam combiners would you need to make it work

Asked by seedorfj 3 years ago

Laser beam oscillating from low to high power?

Hello, i have a green laser pointer, that i love to use. I put new batteries in it, but the beam was oscillating, mean when i pressed the switch and holding it, the dot was high-low-low-high etc.. and now its not tuning on!! when i watch trough the hole, while pressing the button, a tiny red square is in the centre of it, but no green beam. what could it be?

Asked by dsirotic 4 years ago

LED focussing? Answered

How much can you focus a standard 5mm LED? (i.e how tight can you get the beam)

Asked by .Unknown. 7 years ago

IR Beam issues.

So I have been working on an airsoft tripwire type thing. I have the circuit entirely finished. I am using an infrared photoresistor and the one problem I am having is that I can't seem to focus the beam from the IR leds very well. I have three of these ( at my disposal. The IR leds are a pain to line up with the resistor on the circuit. So I ask you, what do you think I could do? Ideas on better ways to focus the beam as well as perhaps ideas for replacing the photoresistor are appreciated. The IR photoresistor came from radioshack. I'm pretty sure this is it:

Asked by DesChamos 8 years ago

micro motion

I all of a sudden got into beam bots as a project to do when I'm bored, anyways what's the smallest device to get motion? THe device also can't be power hungry. would muscle wire work? how many amps do they take? does anybody know how to wind their own micro solenoids?

Posted by guyfrom7up 10 years ago

How Do I Attach /Connect Bistro Blinds To An Existing "Colorbond" Carport?

Hi , I hope there is help here? I have wracked my brain s out !!!  I built an awning off the house - Well I didn't  ...a tradie did... but to my specs..and the awning is useless as it needs sides... so I want to put up bistro (Plastic ) blinds... I think the weight of them will be too heavy .. Or when I screw into a hollow beam I will have no way of stopping the beam from stretching as it's  has thin and light sides...  So I need help Do I go through to the other side of the beam to put into place a ????  Maybe I want a strong metal sleeve that will enable me to screw ? bolt? attach these blinds?? Any ideas? Thanks heaps if you read this ....and have any ideas...!

Posted by screamingjet 5 years ago

Making a Powerful Laser.

Hey all, Could anyone provide a complete beginner with tips or even a complete guide on how to make a powerful laser which could point around a mile away? Any tips are appreciated. Thanks, Lawrence

Posted by Fysh 7 years ago

What can i use to produce a tone of 33 hertz?

I've heard that this is the tone that the infamous Blaster Beam from Craig Huxley plays at and stimulates some women. What can i use to either reproduce the effects of the Beam or just produce this tone?

Asked by EragonShadeslayer 8 years ago

what is the spesification of photocell in this scematic????

In the arrangement of laser beam home protection system i need to knw the spesification of photcell used inthis arangemt and also the laser intensity i.e hw many refelctions it can endure and how much area it can cover??

Asked by 9260074 8 years ago

Electrical requirements of a DVD drive motor? Answered

I've just ripped up an old DVD drive to re-use the motors in a basic BEAM/Solarbot. Its clearly marked with the polarity but I'm unsure of its electrical needs - will I need to use a certain spec'd solar panel/capacitor to supply its power needs? Or will it simply work with whatever I supply it (lower torque/power aside)? I'm short on electrical know how and looking to build both theory and practical knowledge tinkering around. I've seen a number of kits that have solar cells that supply 4.5V / 18mA - but assume this would be more applicable to how fast the capacitor is charged.

Asked by cloudy-wind 8 years ago

LED reflectors? Answered

Why don't they make LEDs without the reflectors? I find that LEDs don't throw their light very far (it spreads out quickly) and even if you were to put them in a torch, the majority of the light would go out of the torch and spread then, making the reflector quite useless.

Asked by .Unknown. 7 years ago

Help with BEAM robot please!

Hi all! I am starting to build the famous mousey robot but I ran into problems already, I am a newbie!. If someone could give me a hand that would be very appreciated. I have all the parts except for the relay which I hope will arrive anytime soon (had to buy it online) attached is a diagram I drew to use as a guide when breadboarding the first part of the circuit that makes the robot seek light. The problem is both motors work and spin but they don't seem to change the speed when I cover one of the light sensors. If I use the multimeter on the light sensors while disconnected from the circuit it gives me 0.04 volts for both, positioned in such way they receive the same amount of light. If I move them the readings are different ( more if closer, less I farther away). But when they are connected as shown and I measure voltage they both give me the same value no mater which one I cover with my hands, also, the value changes if I move the light source. I am using a breadboard to connect the light seeking circuit but I will attach images later it is the same as the attached image (I hope) the difference is the image was drawn with the circuit board I am going to use.Also, I measured the voltage motors were getting while running with a different light sensors covered at a time and both motors gave me the same ~4V.. I think that means they are running at the same speed right? I think that the instructable about mousey in this site still has the led error but I am not sure.corrected? circuit diagram also attached a second diagram of how it should look when completed with relay etc. I drew them so they might have errors!Thanks a lot, any help would be very appreciated!edit: more related links:

Posted by brunoxyz 10 years ago

Focus a laser-like beam from LED(s)?

Is it possible to focus a beam from an LED so that it makes a laser-like beam? Could it be made to burn? I've heard of simulated lasers that sound like they use LEDs focussed into a beam.

Asked by DIY Emilio 7 years ago

is it possible to make a laser beam more powerful by adding more lasers?

Iv been looking at the laser cutter 'ables and am wondering it its possible to combine say 10 fairly high powered (cheap/er) lasers into a single beam to create a more powerful burn. id prefer not to go out and buy $2000 worth of laser which ill most likely break. or get arrested for trying to bring through customs. i was thinking of using a diverging lens to make the spread out rays in a parallel path. in diagram i understand that mounting the lasers will be a challenge.. but will constructive/deconstructive interference be a problem.. i didnt listen to well in physics. any ideas would be appreciated grim out.

Asked by grimgroper 8 years ago

Opening and closing beam katana (Tsubaki from No More Heroes)

I recently decided I'm going to go as Travis Touchdown for Halloween, and a friend and I decided we were going to attempt to make the Tsubaki Beam Katana. (the one in the middle)We've thought about making one that is always closed, (not able to extend out to open position) so I can wear it on my belt. But where's the fun in that. So we thought of course about making one that will always be extended out, (not able to collapse into closed position) but it would be cumbersome at times that I would need both my hands wherever I was, and I don't like putting things down, just so I can come back to it to see that it's been handled by someone else and broken, (I plan on it being sturdy, but still, someone will find a way) or even worse... missing. So I guess the only option would be to make a fully functioning one (being able to extend and collapse through the use of buttons, and when extended out, pressing a switch to turn on a light for the "beam")So basically this without the hitting of people part. lolThere is multiple ways I've thought on how to approach this, the simplest, but non awesome way, would be to just use gravity, like the old school toy lightsabers. If there's no other way, I guess that will be what I have to end up doing. But, lets not give up so soon shall we? I've thought of using a long spring, but the only place I thought of where to put that would be in the tube that would light up for the 'beam', but once lit up you would be able to see the shadow of the spring projected onto the tube, and I don't really want that. Another idea was to use air pressure somehow, I really don't know how though, this kind of stuff isn't exactly my forte. And my last idea was some gears that could possibly be used on the stick piece that extends on the outside of the beam, to hold the top of the whole beam katana, but that might be hard to pull off since that piece is going to be sectioned like an antenna that extends out.So what I'm asking for is different ideas that I could possibly use to get this thing to shoot open on command. I would like for it to shoot open and snap closed, but being able to get it to only shoot open seems more plausible in this situation. (and just manually close it by hand) But if you have ideas for it to open AND close on command, then please share, for I just may try it.Thank you for your time in reading this, and any help you have to offer.

Posted by SamuraiSamori 8 years ago

Summer Camp seeks proposals for ambitious collaborative project

Calling all Engineers, Designers, Sculptors, Builders, Videographers, Architects, Artists and Makers of all descriptions and disciplinesSUMMER CAMP SEEKS PROPOSALS FOR AMBITIOUS COLLABORATIVE PROJECTSBeam Camp requests project ideas for 2009 and future summers.You supply the plan and vision. We'll supply 100+ energetic campers and staff and 700+ acres of forest, mountain and lakes as studio, canvas and workshop. Submit your proposal to be Beam's 2009 Project Master. THE PROJECTEach summer Beam commissions a Project Master to design a unique large-scale collaborative endeavor that campers produce and enjoy. The Project can range from the conceptual to the structural. We are looking for big ideas that will challenge and excite our campers and staff. Our Project Management Team will work with the Master to "translate" the Master's project blueprint into the camp context.THE CAMPBeam Camp is a 4-week summer program (July 18-August 16) for boys and girls aged 7-17 in Strafford, New Hampshire. Beam Campers cultivate hands-on skills while exploring innovative thinking, design and the creative process. They transform ideas into artifacts and personal achievement into community success. Teams of campers work on different aspects of the Project each morning. In the afternoons, they participate in Domains, mini-courses in arts, athletics, science and nature studies.Project CriteriaMake it big.Don't limit yourself to "camp-y" themes.Construction can be a central component, but doesn't have to be.Past Projects:2005 The Nexus Canopy: a raised, 42' x 36' grid of wood and fabrics that the campers transformed from shelter to maze to movie theater to art installation to banquet space. Project Master: Fabian Jabro/Standard Architects2006 The Beam Fleet: seven wooden vehicles, designed, and built by the campers, equal parts kinetic sculptures, simple machines and rolling canvases. Project Masters: Steve Gerberich & Nathaniel Leib2007 The Beam Micro/Macro Domes: five geodesic domes based on the forms and structures of virus proteins, that became shelters, sculptures, playspaces and activity centers. Project Master: Caitlin Berrigan2008 Jungletopia: three tree-houses ring a 16-foot armature to form a play/contemplation space that bridges (metaphorically and physically) Beamers' imagination and craft with the forest environment. Project Masters: Jan Drojarski & Jon BockselFAQsHOW DO I SUBMIT A PROPOSAL?Go to to fill out the Project Proposal form or send an email to'S THE PROJECT BUDGET?We generally spend $10,000 on Project-specific materials including any necessary new tools/machines.WHAT ARE THE MASTER'S TIME REQUIREMENTS?Upon selection of a Project, Masters have until May 1st to create a blueprint or working plan for the project. We ask that the Master be available for at least two pre-camp planning meetings and join us for at least three days during the camp session.DO I GET PAID?Project Masters receive a $2,500 stipend plus reimbursement of travel costs. Proposals due: March 1, 2009.For more info on Beam: http://www.beamcamp.comFor further inquiries contact: Brian Cohen:

Posted by Brian Cohen 9 years ago

Can I turn a laserbeam in a Bigger and wider beam??

Hi, I'm working on a new project and it involves a detection using a Laser... Because the beam is to thin to detect an object i need to increase the thickness of the beam... Is this possible using some sort of lenses? or is there an other way of doing this? Thanks for helping! Greetz Kenny

Asked by zupperzipper 8 years ago

Dividing a laser beam

I'm working on a project that utilizes a series of laser beams, about 8. Instead of having 8 separate laser pointers/diodes, I think it would be easier if I were to find a way of splitting the beam of light from one into 8 beams of light. Does anyone have any ideas? Something like shining it through angled Plexiglas or some kind of prism?

Posted by whatsisface 10 years ago

how do you make a laser beam combiner?

Im trying to combine a red and green to make yellow

Asked by Jake Morton 8 years ago

broken beam switch for audio loop?

I  want to have a set up that play a message or sound every  time a light beam is broken.  how should i do this?

Asked by instructarnie 5 years ago

how do i find out values on old barn wood and beams?

Barn wood values and hand hewn beams values

Asked by elizabeth+fisher1231 7 years ago

Direction Lens?

Is there a lens that takes all the incoming light and sends it out in one dirction

Asked by 7 years ago

1381-J replacement for Miller Solar Engine?

I know BEAM robotics have fallen out of style a bit, but I hope someone is still mucking about with them because they are super cool.  I am working on a Miller Solar Engine and trying to find a replacement for the 1381-J voltage trigger. I tried out the DS1817. It was recommended to me by one the technicians at Digi-Key as a replacement for the MN1381-J and on paper it looks like a good swap, but in the circuit it is just not resetting once the voltage drops.  I have it breadboarded and I can stick the 1381 in it and it works perfectly.  When swapped with the DS1817 it triggers once the top voltage is reached, but then never resets (it just drains forever.)  I double-checked the component type to make sure it was just not a miss shipment of the wrong item, but it checks out.  And I tried swapping the DS1817 component out thinking that I just had a dud (or 5) but it does not seem to help.  Any thoughts? Here are the data sheets on the 2 items. one bit of weirdness I already figured out is that the 1381 looks like it has a different 1-2-3 pin out sequence at the top of the PDF but it turns out it does not at the bottom.

Posted by kaczchris 4 years ago

Problems with Mousey the Junkbot... Answered

I am a young boy with an interest in robots (and electronics). I recently attempted to build my first robot (Mousey the Junkbot.) Unfortunately it did not go well. I was hoping someone would be able to help me. I have tried to wire it up and when I try to run it, I run into a few problems. the motor wires from the relay are like positive and negative leads. when i hook them up to the positive leads on the motor, the ground connection coming from the LM386 basically does nothing and hookup the leads making the motors run like a series circuit. Also, the reverse switch just makes the motors stop for a few seconds then the motors start up again. When i press the reverse switch, sometimes (not always) the relay clicks, then rattles, and the wires become significantly warmer. There are a few variances in my robot than specified. They are: I am using a 12v computer relay instead of a 5v relay, and i am using an LM386N-1 chip instead of the LM386. I believe the problem is the relay, but i have the understanding that the relay is only used for the reverse circuit. if so, is it possible to omit the relay and try to only make it "Light Seeking" without the runaway circuit? Also, I am deeply confused with the wiring for the light sensors. i have found that Make Magazine says to put it in series with the Led, the "corrected" circuit diagram shows it connected to the positive lead of the Led, and the Instructable shows it should be connected to common ground. I hope you can help me! Thanks!

Asked by Chowmix12 8 years ago

Laser beam security

Hi all, I'm new to this forum and here is my question: How do I find the schematic for the laser beam home security system? Using the step by step explanation the schematic is not displayed. Regards HtG

Posted by HermantheGerman 10 years ago

How to narrow an IR beam which comes from several IR LEDs at one place? Can I use a lens for this? Answered

How to narrow an IR beam which comes from several IR LEDs at one place? Can I use a lens for this? This is for a university project which is to track an IR beam's pointer movement.

Asked by lks0912 8 years ago

solar light to laser beam ?

Hello, would it be possible to concentrate solar light so to form a laser beam ? In other words would it be possible to apply laser light principles to basic solar light with the help of optics of some sort ?

Posted by gabdab 8 years ago

How can i focus two or more (infra red) led's into one tight beam? Thanks

This would be for a laser tag gun, more than one infra red LED could greatly improve distance (so it is theorized) but if you think it wouldn't, give us a yell. How it normally works in the gun, is a high powered infrared LED with an already tight beam of about 20 degrees is projected onto a double convex lense about 2 to 5 cm in diameter. The beam is focused by moving the LED back and forwards with snipers having tight beams for the longest range and others having very wide beams to limit range and but improve accuracy at close range. Any help is much APPRECIATED. OH and someone recommended a cube beam splitter but i have no idea what they are so you may want to look them up... THANKS COMMUNITY

Asked by DELETED_D4VOBRO 8 years ago

Troubles making a BEAM bot (Miller engine)

Hey everybody! I'm just getting involved with the wonderful BEAM bots. The problem is that here in Germany I don't get some of the transistors and I have to find alternatives. Instead of the 2N3904 I use the BC546, for the 2N3906 I use the BC556 and for the MN1381 I use the TC-54. I'm attaching the datasheets - did I get it right that I only have to "turn the BC556 around" so the pins fit? However, I don't get the Miller engine working! As a solar cell I use a Panasonic BP-376634 (3,4V - 30mA) As capacitors I used different ones. The motor is a tiny cell-phone vibrating motor - I guess one of the tiniest. As a resistor I'm using a 2.2K. All in all I tried to follow these diagrams: I also uploaded some photos - maybe you can make out mistakes I made... Hoping for your help! Sebastian

Posted by sebarr 6 years ago


I just designed (if it works out) a super efficeint Beam Solar engine that works at low voltages. Before I post it I want to ask a few questions to see if I need to revise my design. 1) MOSFETs work on voltage, no current, right? 2) Do MOSFETs have a voltage drop, like biploar transistors have a voltage drop of about 0.6 volts? EDIT: I got a new design that I want you guys to evaluate that doesn't use mosfets. It's incredibly simple and I want to know what you guys think. How it Works: The solar cell energizes the transformer coil while turning on the transistor. The transistor shorts the circuit and then the transistor turns off, then it repeats creating pulsed dc that drives the stepup transformer. I chose this design because there's very little components and there's no voltage drop across the transistor to the transformer. Theoretically this could run on as low as 0.7 volts, which is good for BEAM robots.

Posted by guyfrom7up 10 years ago

How to make a tv screen's electron beam constant, not pulsed?

I got an old black and white mini radio tv. I hacked the yoke to turn it into a vector display. The problem is that the beam electron beam is pulsed, rather than constant,  causing dotted lines. How do I make the beam constant? Should I bypass the internal RF input circuitry and replace the normal input with something else? Is there an easier solution?

Asked by magnum-colossus 7 years ago

how hot is a laser cutter beam? Answered

How hot is a laser cutter beam? I was thinking of using a magnifying glass and the sun to burn into metal or stone.  And when I say magnifying glass I meant using a giant frens lense Overall my goal is to carve into metal, stone or brick.

Asked by Houdinipeter 6 years ago

Does the point at which two light beams coincide appear to be more visible/greater intensity than the beams themselves? Answered

Specifically, i'm interested to know if the coincident point of two laser beams would appear to have a greater brightness / intensity than the beams themselves. For example, I think I read somewhere that 15-25mW green laser diodes have a visible beam in med-low light conditions because they offset dust particles? So does this mean that where there are two light sources approaching from different angles that there will appear to be a greater amount of reflection from the dust particles? Any information would be useful really, just to put my mind at ease... Thanks :)

Asked by DELETED_Alexdlp 6 years ago

laser beam alarm using NE555 ?? circuit question

Hi all my project idea : using laser beam and LDR to make a security alarm circuit , when the beam is cut , it will trigger the NE55 circuit for certain time (5 seconds only ) there is a lot of 555 dark-activated circuits on the WWW,  i know , but all of them are like on/off switch what i need is one with adjustable delayed time can you help me ??  thanks in advance

Asked by lu2a 7 years ago

electric eye

I would like to make an 'electric eye'. When the eye's beam is broken, it will close a switch and send power to an ac/dc converter. When the beam is restored, the switch will open. suggestions?

Posted by jepalmer 9 years ago

Would it be possible to focus a laser beam to an even smaller point? Answered

I was thinking maybe fresnel lens+ high powered laser+ even more high powered laser!!

Asked by norsehorse 9 years ago