Find some elastic bands that have the same width as the bearings and also fit over the circumference of the bearings nice and snugly.
Build a 23.5mm based mpcnc. Except all the parts that don’t house any bearings are printed from the 23.5mm parts list. Top corners, feet etc.
Then for the rollers and any other part that houses any bearings, print them from the 25.4mm parts list.
Obviously the rollers won’t fit as they’d be too loose, but the elastic bands over the bearings should take up the slack.
If it works, you would have some nice little rubber wheels instead of the hardened steel bearings on the mild steel conduit.
Which should eliminate the possibility of wearing grooves in your conduit and make it all considerably quieter.
Of course the hardest part would be finding the right sized elastic bands. But surely there must be some out there somewhere.
Will it work? Don’t know. I’m just throwing the idea out there in case anybody else is curious enough to try it.
I think Ryan has slightly different offsets in places for the different sized parts. I would worry they wouldn’t fit quite right. Is this a problem that really needs to be solved though? The mpcnc is pretty loud when it has thw router running.
On my ZenXY, it rides woth bearings just on the top of some rails. I tried adding some heat shrink to make it quieter and I think that worked well (for noise suppression), but it changed the diametwr a lot.
plus anything soft like that will add jitter. It might be minute but if a band breaks during operation could be very bad. Even a minor tilt could be bad
I gave your idea a lot of thought, and can’t think of anything that would work. Maybe powder coating rails. But not sure. And is that really worth it. No.
EMT is dirt cheap and I don’t think it needs replaced that often.
I love the creative idea. I love to hear new ideas and I encourage everyone to share ideas. So please don’t take my words as criticism. They are indented to help improve the idea as far as my experience allows.
Elastic or rubber bands would introduce flex that could cause you to lose precision. Also they would break down and tear very quickly under pressure. As a test you can see how heat and pressure destroys most elastic bands. Take a band and stretch it out quickly several times. Then feel the heat it generated then notice how it isn’t as tight as it used to be. Elastic chemically breaks down quickly with heat and pressure.
They only way I could see to make that work would be to print nylon caps for the bearings. Nylon can usually take the abuse and it can cause rolling parts to be quite. For instance garage door rollers. The upper end rollers are made out of nylon because they are quite and strong.
The problem with nylon is that it is very difficult to 3D print. Not all machines can handle the high temperatures required. And it shrinks when it cools so it takes calibration trial and error. It requires more skill and experience to print well.
Not impossible but a little difficult for new makers get right.
again I like the idea.
Jeffeb3 is right about the tolerance and offsets. Mixing the different sized parts won’t work because they won’t line up. So if this idea was adopted it would have to be a new universal size design.
Can I just say I love this community. People who love to tinker and come up with new ideas. Thanks everyone! And Merry Christmas!