Re: Thingiverse "Threadless Ballscrew" - Customizable (level 2 - Techie)
AWESOME JOB BRO! i cant wait to give this a go!
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SoliForum - 3D Printing Community → Hacks & Mods → Thingiverse "Threadless Ballscrew" - Customizable (level 2 - Techie)
AWESOME JOB BRO! i cant wait to give this a go!
-For good measure I have cheated each bearing towards the smooth rod by .4 mm. This should make for a VERY tight connection
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...
2n2r5 wrote:-For good measure I have cheated each bearing towards the smooth rod by .4 mm. This should make for a VERY tight connection
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...
That might be worth trying then after cutting the grooves using a case hardening compound.
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.
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 think you will notice an issue with the mounting depth of the nuts. It is something that I never really got around to perfecting. The nuts should fit most situations. you might have to make the main body a bit taller than you would like though. I am curious about the small bearings. I tried some 623zz and noticed they didn't have enough holding torque. I think that was due to me not having the right size M3 screws and therefore didn't have nuts on them either. Since I would have had to order the right ones it was just easier to use my 625zz with the M5 screw instead. Make sure to grab the latest script from thingiverse. That should be the latest version.
I'm excited for someone to try this out. I finally got smart after 3-4 revisions of this. I printed a test version of these at 20% infill and then did a quick dry fit on 8mm rod outside of the printer. If i could slide the assembly down the threaded rod with with anything less than 20lbs of force then I didn't install it or bother printing the high infill one.
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.
Ok I have test one printed at 0.15mm height, 3 perimeters and 20% fill with support on a Replicator.
Don't have the printer in front of me to test the alignment of the mounting screws on the wooden platform but the bearings are really snug. I went M3 screw, washer, bearing, washer, printed part, nut. The nuts are tight underneath because of first layer squish but pulling them in with a longer M3 screw did the trick. No clearance issues with depth.
The grip is stupidly tight. I have to push down on it as hard as I can to get it to slip and then it moves about 1mm. I think tensioning the nuts to get the right amount of ease of turning will be paramount. Already the bearings are so tight they are marking a spiral pattern on the polished rod.
I assume setting the bed to wood will set the spacing to 16mm?
I'm going to try and tweak the settings very slightly to create room for the original lock nuts that hold it together. If it works I'll post up a link to the Thingiverse link.
Great work, 2n2r5. From the test one I'm 100% confident this will work and be reliable.
Ok I have test one printed at 0.15mm height, 3 perimeters and 20% fill with support on a Replicator.
Don't have the printer in front of me to test the alignment of the mounting screws on the wooden platform but the bearings are really snug. I went M3 screw, washer, bearing, washer, printed part, nut. The nuts are tight underneath because of first layer squish but pulling them in with a longer M3 screw did the trick. No clearance issues with depth.
The grip is stupidly tight. I have to push down on it as hard as I can to get it to slip and then it moves about 1mm. I think tensioning the nuts to get the right amount of ease of turning will be paramount. Already the bearings are so tight they are marking a spiral pattern on the polished rod.
I assume setting the bed to wood will set the spacing to 16mm?
I'm going to try and tweak the settings very slightly to create room for the original lock nuts that hold it together. If it works I'll post up a link to the Thingiverse link.
Great work, 2n2r5. From the test one I'm 100% confident this will work and be reliable.
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.
I measured a SketchUp file I had for the M5 nut holder which was 16mm spacing, so I'm thinking yours matches.
100% fill version is printed and assembled now. About to take it home and test it. I tweaked a few things to make it more compact, such as lowering the overall height to 11mm, the diameter to 32mm and changing the pitch to 4mm to give more steps per mm.
I need a few more M3 nuts but the test fit of the final one feels spot on. If the bearings are too tight, I've been shimming them with M3 washers to raise them up until they can be done up tightly without binding.
Will report in a couple of hours.
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.
Hey 2n2r5,
What bearing angle would you prefer to receive the metal version in?
11.2517° degrees?
also how important is the accuracy of the degree?
Hey 2n2r5,
What bearing angle would you prefer to receive the metal version in?
11.2517° degrees?
also how important is the accuracy of the degree?
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.
Ok no problem
Got the metal in friday
still waiting on one more tool and then I should be able to start machining soon.
that's pretty
Wait till you see her machined
one of the best mods so far!
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.
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.
My plan is to drill out the z stepper mounting holes bigger, and then use a large flat washers on the stepper bolts so I can reposition in line and tighten.
Should have more time on the weekend to play with 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.
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.
How are the test prints looking?
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
Another interesting thing is the shallow grooves the bearings are pressing into the polished rod. I've recycled the original Solidoodle x axis I had spare from when I upgraded the carriages.
Another interesting thing is the shallow grooves the bearings are pressing into the polished rod. I've recycled the original Solidoodle x axis I had spare from when I upgraded the carriages.
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....
Test prints are in. Z rod wobble ranging from impossible to spot when bed is near the top to bloody obvious at the bottom.
You can see the wobble manifesting itself in the prints as banding.
Blue piece was printed previously with M5 threaded rod and slop nut. Yellow are new and 0.2, 0.25 and 0.3mm layer heights from left to right.
Question is what can I do to eliminate misalignment in the z axis?
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