Thingiverse "Threadless Ballscrew" - Customizable (level 2 - Techie) (Page 2 of 3)

Yes, and if you use mild steel rods for giggles, you can actually score in a 'thread' with the bearings... makes me wonder if it would convert to a ghetto-ballscrew by just cutting a v-ramp channel for the bearings to travel in...

Hi 2n2r5,

I think I read somewhere here that you people hadn't followed through with fitted this and giving some feedback. I just finished compiling the bits I need to do the mod.

I ordered 5 x 3mm x 10mm x 4mm (QTY x Id x Od x W) bearings since I have so many M3 screws sitting around already. I've cut down my spare 8mm rod to 200mm (Solidoodle 2 with wooden bed) and I have a new flexible coupler.

Today I'll have a go at manipulating the scad file to my specs and ask back if I get stuck.

Hopefully I'll have it fitted soon to post up some pics of the results.

I've used the customiser on Thingiverse and output my part. I went with 4 bearings as suggested and I can always try 5 with a custom rectangular shape base if need be. Since I have holes drilled for my previous ball screw arrangement, I'll make the base really wide so the mounting screws don't foul on the bearings and screws.

Hopefully print a test one this morning and report back.

Sounds like it is working as it should! That's awesome that you got results on the first go. I worked pretty hard on it at the time.

I can't remember the exact spacing that I put in the file for mounting to the wood bed. I think it is the same spacing I used for the slopnut.

Fitted the part, everything seems to be ok.

Updated the steps per mm to 800 to reflect the 4mm pitch. Quick test reveals accurate distances for z (requested v actual).

The configuration I ended up with fits the standard wooden bed perfectly with room to attach the original M3 lock nuts on the top. They *just* clear the bearings.

http://www.thingiverse.com/thing:165895

Test print is ok, similar to M5 rod with slop nut at this stage.

Main problem is severe wobble that sends the rod from left to right. This is nothing to do with the threadless ballscrew, because the same thing has happened when I have experimented with ballscrews and acme lead screws. I think something is misaligned from factory with either the timber bed mounting holes or the z stepper holes.

I will try to get up a short video.

I think people from the original thingiverse page said that between 9 - 11 degrees worked best. I would imagine that the metal version would have an advantage over its plastic counterparts and could still be effective at a lower angle. I will try what ever you come up with though. As long as the angle is the same for all the bearings it should work great.

Got the metal in friday
still waiting on one more tool and then I should be able to start machining soon.

Wait till you see her machined

That's great that everything is fits but sorry to hear about the rod wobbling. That is one of the things I really like about this. My rod doesn't wobble at all. Sometimes it's hard to tell that it is even moving.

Hopefully your prints don't suffer because of it.

After filming the video to show the Z rod wobble, I found that the coupler wasn't quite in place correct. With some attention, wobble seems to be fixed.

I'm printing some test cubes at the moment at various layer heights to test.

Tricky time right now because we've just put our house on the market and I have to keep the printer in the garage where it can't be seen.

Hoping to drag it out today to test a bit more.

Having a strange problem where the front of prints are printing too high, as if the print head is angling back as it comes towards the front of the printer. The rear side of the objects look great, however.

I've updated my Thingiverse derivative with a pic, as you can see in the current configuration the stock screws JUST fit:

http://www.thingiverse.com/thing:165895

Yeah I get this on the stainless rods too. I suggested earlier in the thread that with the right cut on the rod, you could turn this whole setup into a poor-mans-ball-nut... just need to cut it so the thread 'face' is square to the bearing racer face....