Low friction "bearings"

For several of my projects I required some sort of bearing that would not only allow for a minimised free play but also very low friction.Before you get too exited: This is not a new type of bearing or anthing for heavy duty loads, not even for ongoing use without servicing.I found that even slightly heavier things rotated on makishift bearing far easier if the axle was verticall instead of horizontally.This gave me the idea to try a simple needle-bearing approach.This is how it goes:1. Grind and polish your axle to get a nice needle point - it must be perfectly centered!I prefer to do this with the axle in a fast spinning drill on a fine grinder.The polishing in a simlilar way, but please do not try it with a cloth in your hand on a spinning axle!2. The other part of the bearing is a screw or pin with a punch mark.I grinded and polished a punch for this so it has an angle of 60° and polished it to a mirror finnish.If alignment is of importance then of course the pin/screw must work for this purpose!If in doubt make it spind an use a pencil to get the true center.A drop of sewing machine oil and it spins nice and with very little friction.The key is to adjust the gap(s) between axle and punch mark to next to nothing.You don't want any pressure along the axle as you would "drill" a hole into your mounts.And you don't want it too loose to avoid wobble.I hope it might give you an idea for your next project.

Topic by Downunder35m 2 months ago


Acrylic on acrylic hinge - friction?

I'm building an articulated 'puppet' using 3mm acrylic sheet for the 'skeleton' My hinges will be simple sandwiches of two outer and one inner piece, held together with a snap-together nylon rivet. The flat contact area is about half a square inch (see attached image). The 'puppet' will be controlled by tendons attached to gloves, so will only have the force of single fingers to move them. I need to know how smooth a joint this will be, before I start ordering nylon washers. Anyone got experience of this sort of join? Will it be ok dry, or will a small amount of  lubrication help? (petroleum jelly? liquid silcone?). Or do I need to commit to washers. Needs to be as frictionless as possible!

Topic by Crispy75 8 years ago  |  last reply 8 years ago


What is an easy and efficiant way to harvest static electricity? Answered

Question by Mr Cheeseo 10 years ago  |  last reply 10 years ago


Mechanical ball and socket joints with specified tension? Answered

Okay mechanical engineers: what I am looking for is a ball and socket joint with a tension rating. The idea is to make a lamp that has an adjustable angle fitting for aiming the light. Is there a name for a metal joint composed of a metal ball bearing surrounded by a sleeve (socket) with a determinable amount of friction, adjustable for the weight of the adjoining object?

Question by Nate Cougill 7 years ago  |  last reply 4 years ago


Friction drive weedeater bike?

I am wanting to make a weed eater bike and I am having trouble figuring out how to get the bike peg onto the clutch shaft. Can I just thread the clutch shaft with a tap and die set (which I don't have). Would it work if I put the clutch shaft against the wheel instead of putting a peg on it? Also, how hard is it to mount the engine with angle iron since I don't have a welder?

Question by chiefs543 7 years ago  |  last reply 7 years ago


Question about thermodynamics??? Answered

The zeroth law states that any 2 or more objects that come in contact must exchange energy to create a thermo equilibrium.  Would 2 magnets of the same polarity in a vacuum still abide by this law?  Can someone give me a formula to explain it?  Can magnetic fields even make heat by themselves or rather is there any friction between the two??  Thanks much!

Question by shawneegeek 8 years ago  |  last reply 8 years ago


What mysterious force holds the plastic pizza signage to the top of this moving car? Answered

The attached photo was taken recently at an undisclosed location, somewhere in the Former United States (FUS). In it you can see a plastic sign-thingy on top of a moving car. My question is this: What mysterious forces keep the plastic sign-thingy from sliding off the car due to the effects of wind and inertial pseudoforces. What holds the sign to the top of the car? Is it powerful magnets? Double-sided sticky tape? Is it perhaps... love? Has anyone seen one of these artifacts up close, and/or knows for sure what the physical mechanism is?

Question by Jack A Lopez 9 years ago  |  last reply 7 years ago


diamond cutting steel.... Friction cutting?

Recently got a diamond wheel for angle grinder.   tho it is marketed to cut tile, marble, etc, i tried it on steel.  cuts quick enough, but leaves huge burrs. burrs 4x thicker than the workpiece.   seems the blade just melts and squishes the steel out of the way.  it works, kinda, leaving a hazardous ragged edge on the work... i see why they dont market those blades for  steel. im reminded of friction cutting blades.

Topic by Toga_Dan 4 years ago  |  last reply 4 years ago


Friction Drive Weed Eater Bike?

I am wanting to make a weed eater bike and I am having trouble figuring out how to get the bike peg onto the clutch shaft. Can I just thread the clutch shaft with a tap and die set (which I don't have). Would it work if I put the clutch shaft against the wheel instead of putting a peg on it? Also, how hard is it to mount the engine with angle iron since I don't have a welder?

Question by chiefs543 7 years ago  |  last reply 7 years ago


Book cover Hinge

Hey all. First time poster here (second attempt, since Instructables stopped responding the first time) so hopefully I am posting in the appropriate place. I have in mind a leather-book-style cover for my tablet that I'm very excited to work on. However, I would like to use friction or torque hinges to position the cover at any angle  from the spine in a 180 degree radius and have it stay there, similar to the screen of a laptop rotating around the hinge. I've included a picture that shows the basic design that I'm aiming for, though the hinge itself doesn't need to be ornate. Unfortunately, I don't really know where to find such a thing. I've looked on various furniture hardware sites and taken a trip to the local hardware/home improvement stores, but I haven't found anything that matches what I'm looking for. Common small brass butt hinges would be ideal if they had friction/torque properties to them, but I can't seem to find anything like that. I've never looked for specific hinges before though, so for all I know they've been right in front of my and I didn't realize what they were. Does anyone know where I can find such hinges, or can someone offer up an alternative solution? Perhaps there is a way to add friction to simple hinges bought from a hardware store. Thanks in advance for pointers/advice.

Topic by wireframewolf 5 years ago  |  last reply 5 years ago


Would this idea to prolong battery life work? (NOT perpetual motion, just extended life!) Answered

A few days ago, I designed a self-charging battery system using a dc motor attached to a rechargeable battery pack that turns a generator via gears, similar to how a car battery works, converting kinetic energy from the motor to electrical energy with the generator and looping back to the battery. I've modified the idea to reduce friction as much as I can so that the motor and generator are directly attached now, keeping energy from being lost to friction between gears. Here's a crappy diagram:    |-----|--------------|                     |--------------|-----|    |       |  Motor       |-------||-------|Generator|      |    | | ---|--------------|                     |--------------|---| |    | |------------|----------------|------------------------| |    |--------------|  Battery      |--------------------------|                       |----------------| I know that 100% efficiency is impossible, I'm not trying to get all the energy back, and I'm not trying to create energy. I'm trying to loop the energy that isn't lost to friction and other factors back to the battery, hypothetically charging the battery up a little to somewhat extend the life. I realize that it will eventually go dead no matter what I do due to the laws of thermodynamics. What I want to know if this would increase the battery life enough to be worth incorporating in a design. (I know the motors should be attached to the battery by two different ends but its actually supposed to be a rechargeable battery pack so one motor is attached to input in to charge the battery and the other is output so the battery powers it. Plus if I tried to draw the wires like that it would've taken forever.)

Question by ALogan97 8 years ago  |  last reply 8 years ago


Hoax? A task not only for high-schoolers...

       Well, exept for being quite a fun thing to watch, it also should work as a great Physics problem for someone like me (or a bit younger)-studying all sorts of Mechanics and Newton's Laws to work on... The task is to estimate the acceleration the motorcycle should have to do it, and whether it's significantly larger than the one stated in some technical data (there is the motorcycle model somewhere in the video's name).        If you have a go on it and are a) school-aged and b) not sure you are right, PM me. If you simply want to share your results and/or opinion, write here (but try not to put any solution-I mean formulas). In case the video doesn't work

Topic by gruffalo child 8 years ago  |  last reply 8 years ago


i am making a friction drive motorbike Answered

I am make a direct friction drive motorbike with a bmx bike and a 25cc weedeater i am going to mount it on a hinge and i will use a spring to tighten down the spindle. the hinge is just some angle aluminium mounted to the two bottom holes of the engine. the aluminum is just connected two a bolt that goes over the brake cross section. the spring goes from the end of the angle aluminum to the wheel axle. is that enough or do i need more?

Question by BIGHAIRYDUDE 8 years ago  |  last reply 8 years ago


How do I make a yoyo sleep for 3- 4 minutes ? Answered

I have loved yoyoing from birth. I have been wondering how to make my transaxle yoyo sleep for approximately 3-4 minutes. Do I just need to get better friction stickers? Is there any way to make stickers as well?

Question by Toxicity 9 years ago  |  last reply 9 years ago


Decorating bike with duct tape: weather/friction proofing help? The tape is peeling from the friction of my legs.

I was already thinking of acrylic spray since I live in rainy Portland.  Would acrylic be enough to weather and friction protect it?  Should I cover the whole shebang with clear packing tape then spray acrylic?  Would that make the clear tape opaque?  Other ideas?  Not experienced with paint, adhesives, cover stuff, etc.

Question by peanutduck 7 years ago  |  last reply 7 years ago


How to make solenoid retract when friction applied.

I have a 12V solenoid that was going to be used in a project with a spring loaded door. It was wired into an arduino project and all was going well. That was until I realised that if the bolt had any friction on it that it would not get retracted when power was applied.I wonder therefore whether there is a simple way of making the bolt retract even when friction is being applied?Alternatively, is there a simple mechanism that could be made where friction can be applied to something else that doesn't add friction to the solenoid bolt itself so that when the bolt is retracted the secondary part is free to move and release the sping loaded door.Any help would be appreciated.

Question by mjolnirofthor 5 weeks ago  |  last reply 5 weeks ago


Yo-yo Friction Stickers - are mine "used up"?

I bought a Duncan Mosquito yo-yo 2 days ago, which is the first one I've owned that has a ball-bearing axle and friction stickers. I have been pleased with the long sleep times and pretty good response. Lately, however, both of those have been not so good. The sleep time is okay, although it is somewhat weaker. It seems my string is sliding off of the yo-yo and not getting enough friction to give it extra spin. The previous problem may be related to the following one. When I bought the yo-yo, the friction stickers (which are rubber) were coated in a somewhat sticky substance. After playing with the yo-yo and examining it every now and then, the substance has worn off, and there is no more of it to speak of. My yo-yo has experienced an extreme decrease in response, except at high spin speeds. Although I have learned to bind, I would prefer my yo-yo to respond at least a little bit. Are my friction stickers already ruined? I'm not a pro, so I don't guess I played with it too hard. Is there anything I can do to "fix" my stickers? Thanks, and good luck to all who enter the contest!

Topic by Bran 11 years ago  |  last reply 10 years ago


How to seal a system containing ethanol, but low friction?

Still working on my solar device (in Copenhagen now), and it's coming along fairly nicely. Should hopefully have a full instructable in a couple of weeks. However, I'm having problems at the moment trying to keep the thing water tight, where the axle leaves the system, taking out the rotational motion. I'm using the bearing housing from an old bike wheel (photos to come) and I've got it sealed well where it's attached to wall of the container, but the ethanol is flowing pretty freely through the bearings themselves. I need it not to. I could use something like an O ring to seal the axle, but friction is a big issue. I wanted to pack the whole axle and bearing housing with grease, but grease dissolves in ethanol. Solutions? Is there anything grease like which isn't soluble in alcohol? Salt, maybe? Cheers all. (Nearly there...)

Topic by SolarFlower_org 9 years ago  |  last reply 9 years ago


where can I find 3 1/2" diameter friction drive wheels for a project?

Making a miniature pitching machine for paintballs

Question by PBIF 10 years ago  |  last reply 10 years ago


ornithopter crank does not rotate (rubber band model that i'm building)

When i wind up the rubber band , the crank is pulled back too tightly against the bearing and the connecting sticks refuse to budge due to friction and the wings don't flap.is there a better non friction way to do this?i mean, if the rubber band pulls the crank back through the hook, there's bound to be friction. how do i solve this? please help.

Question by promit.net 9 years ago  |  last reply 9 years ago


Has any one used a down tube friction shifter with a Nexus 7spd internal hub?

I am building an cargo bike, and have a set of down tube shifters and a internal 7 speed Shimano nexus hub. And was wondering if any one had any success or experience with this set up?

Question by sixmillboy 8 years ago  |  last reply 8 years ago


According to physics, does driving with a heavy load increase traction in winter?

Many Canadians enjoy adding weight to their vehicles over the winter to increase traction. How does it work? Since friction is force normal times mu, thus having a greater force normal means more friction. However since mu is usually so small, the increase in friction is negligible as compared to momentum. The momentum from added weight, mass times velocity would be dramatically increases, meaning longer distances to stop and easier fish tails around corners. Therefore less weight is more benficial. This is my logic, and I may be wrong. I don't know, thats why I'm asking...

Question by VentingIntrovert 8 years ago  |  last reply 8 years ago


solidox and sugar

How can I make a 1:1 mixture of solidox and sugar insensitive to friction and shock without making it insensitive to heat?

Topic by MisterHankie 10 years ago  |  last reply 10 years ago


Archery Target

What would be a good way to keep layers of cardboard compressed without using glue so it would have enough friction to stop an arrow ?

Topic by Pat Sowers 11 years ago  |  last reply 6 years ago


how are fluid bearings made?

I was looking at fluid filled bearings and wanted to try and make one i just cant understand how they are filled and how they can rotate without leaking any ideas on how they are sealed?

Question by sharlston 9 years ago  |  last reply 9 years ago


Would a system of gears increase or decrease output?

In a scenario where you have a waterwheel on a river that was turning a wheel, would adding a system of gears increase the wheel speed or decrease the wheel speed due to friction. I have included a doodle to help visualize what I mean. The left side, side x, doesn't have any gears while the right side, side y, does have gears. The gears are made up of pieces that have a small side and a large side. I am pretty sure that the output would be much faster if friction wasn't involved, but I have a feeling that the friction would actually make it slower if gears were added. So, could anyone explain if x side would be faster or y side and explain why? Thank you

Question by Sserdna 3 years ago  |  last reply 3 years ago


would a clutch bell work as a spindle for a motor bike?

I have a weedeater with a clutch on it and i want to make a motor bike as simple as possible and i am asking if you could use the clutch bell itself as a spindle for a friction drive motor bike if so i could probably build one in about an hour and also if so, where on the clutch bell would be best for contact with the wheel, the bigest part closest to the motor, or the smaller part of it farter away from the motor

Question by BIGHAIRYDUDE 8 years ago  |  last reply 8 years ago


why are turret guns more powerful than regular pin guns?

Surely there is more friction in the barrel and turret of a turret gun, like the tr18 or knexsayer?

Question by squarepants 8 years ago  |  last reply 7 years ago


Vortex tube should have a supersonic nozzle for efficiency; a simple drilled hole will not allow supersonic flow, right?

Scientific American had an article on supersonic nozzles in Amateur Scientist.  The nozzle needs to first narrow and then widen, so that maximum velocity is reached by the expanding air. The Hilsch tube seems to be very primitive because of details like the primitive nozzle.  Perhaps, the Hilsch tube was designed to have too much friction.  Perhaps, the tube was built to be sure it was inefficient and not very useful.  The tube can only violate the Second Law if it is built with a minimum of friction losses.

Question by R.Blakely 9 years ago  |  last reply 9 years ago


Super-fast kite-surfing

A new kite-board patent was published in August: a hyrofoil board.A curved hydrofoil lifts the whole board out of the water, cuts friction dramatically and gaining massive amounts of speed.Apparently.

Topic by Kiteman 11 years ago  |  last reply 11 years ago


Tightening the joints of a flexible tripod

I have a Targus Grypton - the small, original version. It's basically a Gorillapod Original clone. It worked great before, but now the head joints have loosened to the point that the tripod is virtually useless. Anyone know of a way to increase the friction so it works again?

Topic by MePerson 9 years ago  |  last reply 9 years ago


make a gas powered scooter out of a weed whacker engine?

I want to modify my scooter with a weed whacker engine,should i use friction drive,belt,chain.i need to make a mount out of would or pipe but i dont have a welder

Question by mman1506 10 years ago  |  last reply 9 years ago


Positive Van de Graff Generator?

I know that a Van de Graaf Generator creates a negitive charge if you use a rubber belt, But how would one make a positively charged friction style van de graaf generator? What materials would you use?

Question by JohnM703 1 year ago  |  last reply 1 year ago


Bearing/fulcrum for a pendulum

I want to swing a locket on a chain like a pendulum and I want to minmise the friction experienced where the chain attaches to the supporting post. What sort of bearing or similar device should I use for this? Ideally it should be available in a bronze/dirty brass colour but I guess I can deal with it if it isn't.

Topic by THX 1138 1 year ago  |  last reply 1 year ago


KLR3

Skunk Rifle Published: https://www.instructables.com/id/KNEX-Skunk-Rifle/ This is what I am currently working on. The KAR-1 did not meet my expectations as a magazine will always cause some friction. I have revisited an older design with what I learned working on the KAR-1.

Topic by MrRadicalEd 8 years ago  |  last reply 8 years ago


Crossbow V2 Ultimate Version

After weeks of waiting, I finally got my k'nex back after moving. One of the first things I did was solving a few problems with my crossbow trigger. It took me about 4 hours of thinking and building prototypes. The following things have changed: The friction has been reduced by a great amount. It became much more compact. Does not require ductape anymore. Does not need the exotic hinge piece. Is now very easy to fire. I decided to show the new trigger using a well-built V2 crossbow; which now can finally use it, due to lower friction. This trigger is ideal for people that want a trigger on the v2, it should be buildable from the pictures. (The coloured trigger is the first version, the same as the gray one though) Edit: Instructable: https://www.instructables.com/id/Ultimate-Crossbow-V2/

Topic by Wicky 9 years ago  |  last reply 8 years ago


Dunkis UMP-45 Video Review

Video for the gun.http://www.youtube.com/watch?v=rLo8oxXPtVcParts-Handle -8/10, a little flimsy, but quite comfortableStock - 8/10, strong, fits the look of the gun and feels niceGrip - 8/10, feels nice, although for someone with longer arms like me it feels a little awkwardMagazine - 10/10, it never jams, has a nice touch, looks sweet and is stableBarrel - 8/10, not long = little frictionPerformance - Range - 8/10, shoots quite far and fast for a magazine gunPower - 8/10, very powerful with little bands because of the low friction barrelAccuracy - 9/10, for me it is very accurate, but it does shoot a little to the left.Overall - 8.4 A very good rifle, everyone who has the pieces should build it.

Topic by bruce911 10 years ago  |  last reply 8 years ago


Worlds First Fully auto K'nex Gun

This is a fully auto k'nex gun. yes i said fully auto. and it actually is fully auto. the pics should explain how it works. its clever because the more elastic bands you put on it the more friction it creates. ive got it just right so the ratio is perfect. ***UPDATE***Video: http://www.youtube.com/watch?v=T-6LPtUgZvA

Topic by Millawi Legend 10 years ago  |  last reply 9 years ago


New Knex Barrel?

I was trying to design a new knex barrel and saw i had an excess of roller coaster parts. So i made a long plain straight piece of track and just attached a rubber band to a cart then the front of the track and it had so much power because of the zero friction barrel. So i was wondering if we could form this type of barrel into a new breed of knex guns. Comment if you have ideas.

Question by KnexFreak360 8 years ago  |  last reply 8 years ago


More efficient bike charger for USB devices?

I' been inspired by these bike lights from reelight.com. I have a set of these for my bicycle for reliable and very effective lighting. It's stated they are powered by "pure induction". There's got to be a way to harness the energy from both wheels to charge a USB device (5 volt) in the same manner. Instead of using a friction generation mechanism bike charger or bike generator.Any thoughts?

Question by rhow 10 years ago  |  last reply 10 years ago


Physics question has me stumped

A large crate sits on a pickup truck which has coefficients of friction mu(s) =0.6 and mu(k) =0.4 . My question is how do I calculate the impact velocity if the truck accelerates (-8.0 m/s^2) and the crate slides forward 1.5 m to impact the back of the truck? Can anyone please walk me through this problem whenever you get the chance? Thank you. 

Topic by GThreep 4 years ago


knex automatic rifle

I had an idea to make a new (i think) type of knex machine gun. it is like knexwizard's semi auto rifle but it has a single shot trigger from viccie.b's crossbow. i made it but it fired its whole magazine (20 grey connectors) in one shot! after modifiying it to put tonnes of friction on the wheel that holds the bands i got it to fire its mag in two shots- still not good enough. can anyone help me?

Topic by the VINdicator 10 years ago  |  last reply 9 years ago


windmill on face of truck/bus ? Answered

The windmill on the car doesnt work as your adding more force in the opposite direction to the work done by the engine. What about using the frictional energy on the face of bigger vehicles like trucks and buses that exist already to run a small windmill. Probably charge a battery or use it effectively in some other way. I cannot see a direct negative to this except finding the way i can place a turbine without increasing the opposing force and using as much of the existing one

Question by ShankarRam 9 years ago  |  last reply 8 years ago


Complex whirligig?

I want to build a 7 propellor whirligig, but theres one catch. Each propeller sopins in the opposite direction from the one before it.Simple enough, Except for one catch. I want all of the propellers to be conected to a central shaft. I think I've figured a way to do it , but it may not be the most efficient way. If you don't have an idea for how to get it done, here is another question.The way I've figured, the propellors "float" abover the gears, but that way they will fall off. Any ideas for securing the propellors for minimum friction?

Question by RGoI 8 years ago  |  last reply 8 years ago


motorised motorized bicycle?

Im looking to make a gas/petrol push bike i have access to all tools exempt welder i have multiple weed eater engines and money is not a problem i am 18 and looking to put a motor on a 12inch bicycle i would pefer chain drive so a gear ratio? i would pefer it to go fast and be rear weel drive the motors dont have a clutch i have seen the one here but there friction drive somone help me out? thanks in advance

Question by 9 years ago  |  last reply 7 years ago


Solar tracker and concentrator: lots of things getting finished.

I'm kind of entering the home stretch on my year long (so far) solar energy prototype, getting the various components finished off and thought yall might be interested. Things such as: Parabolic troughs! Rather efficient water wheels! Low friction worm drive gearings! World's simplest (probably) heat engine! And much more. All made mostly from scrap. I'm posting updates and media to my blog: http://solarflower.blogspot.com

Topic by SolarFlower_org 8 years ago


How do I remove the shifter knob in my automatic transmission 2010 Buick Lucerne?

I recently became the proud new owner of a 2010 Buick Lucerne CXL, and i'm in the process of customizing a few minor things in the interior. Which leads me to my question. As I think the stock shifter knob is very boring and of course standard-looking, I am attempting to replace it with an aftermarket knob that uses set screws. However, I cannot work out how to remove the stock shifter knob to put the new one in, as it is not threaded like most shifter knobs are. I found on an online forum information about the 2006 edition which suggests that in that model year, the knob friction-fit onto the shift column and all you have to do to remove it is put the car in neutral (with the engine off) and pull straight up on the knob. Does anyone know if this is the same for the 2010 model? ANY help would be very greatly appreciated, as i cannot find any information on my model year anywhere else on the internet, and it is not included in the car owner's manual. Thank you! :-)

Question by jester_5123 4 years ago  |  last reply 3 years ago


Mods Mods Mods

MAKE THIS believe me u will like it...hopefully lol long story short it is designed to b as good as i can get it the new mods allow for interchangeable grips a slide can easily be attached w/out any body changes the firing pin is stronger than ever w/ less friction than ever which equals more power try out the mods for yourself and as always be safe and have fun! thanks guys Zak inspired trigger mod is the final pic...it is a must have mod! -thanks Zak

Topic by Knex Lego Maniac 8 years ago  |  last reply 8 years ago


Best ElectroStatic Influence Machine?

What's the best electro-static influence machine?  Like which one can output the best sparks for the spinning input, ie which one is the most efficient? Wimshurst Sectorless Wimshurst (Bonnetti) Van De Graff Voss Holtz Lebiez Leyser Bohnenberger Wehrsen Wilson Or some friction (not influence) based electrostatic machine? All of the influence machines are pretty similar, but I need to make a fairly small one (think disk diameters of only 3 or 4 inches), and i'm trying to make it hand held, so efficiency is a must!

Topic by guyfrom7up 9 years ago  |  last reply 8 years ago


Uses for a K'nex steel rod?

So I own a 39.1 cm (15.4 in) K'nex steel rod, which I got from the 6 ft. Knex Ferris Wheel set. Does anybody know any good uses for this rod? I should point out it is slightly thicker than the typical K'nex rod, has no places to clip on connectors (other than on the ends) and creates a lot of friction with the holes in connectors (so no epic single shots unfortunately). The rod is also quite heavy. The picture is a comparison between the steel rod and a strengthened grey rod (black).

Question by Perk1ns 8 years ago  |  last reply 5 years ago