101 replies to this topic

[JohnnyR24]

Hey guys,

 

For the past couple weeks I've been working on a prototype ball bearing wheel assembly for a knex train. Currently I made the non-screw pieces out of plexiglass but am planning on eventually 3d printing these pieces. After some small adjustments and a couple tests, they run quite smoothly and seem to have a good bit less friction than the standard knex wheels. Has anyone else tried to make custom wheel assemblies or use ball bearings? If you have any pointers/suggestions for a 3d printed wheel assembly like this with ball bearings let me know! Thanks!

Attached Files

•  Knex plexi 1.jpg   90.32KB   7 downloads
•  Knex plexi 2.jpg   108.77KB   1 downloads
•  Knex plexi 3.jpg   125.3KB   1 downloads

[Chaos]

Can confirm the speed part. These trains run so fast - even compared to my best train using silicone spray.

[Britfag]

I know Jogumpie talked about looking for this, but couldn't source affordable ball bearings with the right diamaters I think?

I was thinking about this the other day aswell! Hopefully this is a revolution!  

[Ghostbuster]

That is great! What type of bearings are those?

[JohnnyR24]

I know Jogumpie talked about looking for this, but couldn't source affordable ball bearings with the right diamaters I think?

I was thinking about this the other day aswell! Hopefully this is a revolution!

Yes, It would be sweet if this can become a thing someday!

The bearing's I use are just a little bigger than the diameter of the plastic wheels (might make the rolling a little smoother I guess...), so I wasn't quite able to use/modify easily the original wheel assembly. Other than getting the measurements perfect when cutting the plexiglass, the unit as a whole is real simple and should be pretty easy to 3d print,which I'll start experimenting with in the next couple weeks.

[JohnnyR24]

That is great! What type of bearings are those?

The size of these bearing are 5x11x4mm. These bearings originally have rubber seals on the side and grease in the bearings, so I took off the rubber seals (utility knife-super easy) and got all the grease out by letting them soak in a jar of citrus de-greaser (not quite sure on the specifics of the de-greaser I use right now).

I bought a couple 10 packs off ebay for around 7 dollars each, so they aren't too expensive and 90% of them work quite well once cleaned. I also found a 25 pack of bearings for about $7 as well from China, so I'm going to see if they work as well as these ones!

Here's a picture of what the bearings originally look like when I get them:

[CCreator12]

This is awesome!  I'm very interested in this.  Please post a guide when you get the 3d printer stuff working.

 

I've wanted to make better wheel assemblies for forever but I lack the modeling skills to do so.

[RidesByDaan]

This is great! I've never thought of creating my own wheels. 

 

I hope this can become a thing! If you ever sell a few let me know! Im very interested in buying a couple units!

[Jogumpie]

I'm definitely following this thread.

[maarten12]

Looks really neat! Recently I have actually experienced difficulties with keeping a train running for multiple days, as the lube seems to be collecting a lot of dust inducing a lot more rolling friction. So far your results sounds very promising, looking forward to see more!

[JohnnyR24]

Excited to say I am now onto 3d printing the wheel assemblies. Still in the design and tweaking phase, but here's one of the current wheel assemblies.

 Knex Black 3d 1.1.jpg   79.82KB   3 downloads

Edited by JohnnyR24, 08 April 2019 - 06:22 AM.

[Jogumpie]

Are those ball bearings in metric or imperial sizes? I guess that could make a difference for the rest of the world.

[JohnnyR24]

Are those ball bearings in metric or imperial sizes? I guess that could make a difference for the rest of the world.

They are metric- 5x11x4mm (MR115), which hopefully will be easier to find for all you European folk! 

[SCM]

Is lube still involved with this train? Also, would it be possible to show a comparison between this ball-bearing knex ss train vs a regular knex ss train? I know it performs better but I'm curious as to just how much. I mean this is history in the making right here. Fidget spinners also use ball-bearings, and they can spin for quite some time... 

[JohnnyR24]

Is lube still involved with this train? Also, would it be possible to show a comparison between this ball-bearing knex ss train vs a regular knex ss train? I know it performs better but I'm curious as to just how much. I mean this is history in the making right here. Fidget spinners also use ball-bearings, and they can spin for quite some time... 

Lube isn't in any of the bearings, they are just running dry. I tried to lube up some of the bearings on my custom model coaster with some yoyo bearing oil (very fine and viscous), and it just seemed to slow the coaster down and the bearings also didn't seem to have any harm done when they ran dry. I've read you shouldn't run bearings dry, but for these small/low-impact applications, that's really the only way you can run them so they have minimal rolling friction.

A comparison video is a great idea which I could probably get done in a couple weeks or so once I get some more assemblies designed and printed!   

Edited by JohnnyR24, 09 April 2019 - 12:25 PM.

[JohnnyR24]

Got a small train completed, now the next step will be testing it out! 

[CCreator12]

Can't wait to see the results!

[maarten12]

This looks so neat! I actually ordered some of those small ball bearings, because I want to make these wheel bougies too. How do you plan on testing it, just a drop followed by a slope and see how far the different trains reach? 

[JohnnyR24]

First test runs- they're running pretty fast! Thanks to Chaos for helping with the video and for letting me test them on his coaster! 

 

https://www.youtube....h?v=xvG96xkREus

[CCreator12]

O.o

 

I want so bad

 

God speed with the further development