LM8UU and LM8LUU PTFE (Teflon) hybrid 3D printed bearing

This is a new bearing I designed based on the standard LM8UU and LM8LUU 8mm bearings.
It makes use of commonly available PTFE tubing for the area which is in contact with the linear shaft, combined with a printable bearing housing. This has quite a few advantages; as it's light weight, PTFE has an extremely low friction coefficient and if the tube wears over time it can simply be replaced, without the need to dismantling the linear shaft assembly.
All the files can be downloaded on thingiverse below:
www.thingivers...
Another design using the same principle, but 4mm PTFE rod
• 3D Printed Camera Slider
The PTFE and also 4mm O/D Acetal rods can be purchased from here:
www.directplas...
www.directplas...
coder-tronics.com/

[@Jim_One-wl4ke]

Wow 🤩. Why don’t I think of that ! Brilliant bro. Ptfe tube is cheap and best sliding plastic around👍. The way u make just 4 contacts point make it even less resistance and being hollow has a shock absorbing effect. This is gonna go on my X&Y for weight loss without diet 😂. Thank you for sharing ❤your genius idea .

[@CoderTronics]

Worth trying a slightly harder material which still has low friction properties as did notice the PTFE tube degrade over a few months

[@Jim_One-wl4ke]

@@CoderTronics did u measure the weight? I am now using plastic lm8uu & printed block already save a lot of weight and silent. For your wear case, is it compressed or tube surface wear? Suggest adding 1.8steel rod if compressed is the issue or more tubes or switch Capricorn. Gonna try it myself, thanks

[@CoderTronics]

@@Jim_One-wl4ke it was tube wear, a steel rod would definitely be an option or another plastic like Delrin, Acetal or even PEEK pending cost and availability.

[@MrPao987]

Great idea, I would suggest to make a little twist, literally twist the PTFE tubes inside the housing, so that you get a more even contact surface with the rod. Just spiralize the slots.

[@CoderTronics]

Funny enough I did make a design with that but not uploaded it to Thingiverse, will see if I can dig it out as not used my printer in over 3 years

[@wiradharma7030]

That tube contain silicone, i also use teflon bearing but i made it using ptfe rods.

[@CoderTronics]

@@wiradharma7030 I have tried it with PTFE solid rods as well and they performed ok for a month or so of fairly heavy use, but did deform over time from creepage, I think a better long term solution is Delrin or other harder plastic which still has a fairly low friction level.

[@nadravface]

Thank you!!! I was looking exactly for this solution

[@CoderTronics]

No worries hope it proves useful and feel free to share any makes on Thingiverse

[@robindebreuil]

Great idea!

[@stephenprescott8105]

That is very interesting concept !!!!

[@CoderTronics]

Thanks, I think it needs some refinement but could certainly be promising for some applications. I have made a camera slider based on this principle with solid 4mm PTFE rod and uploaded a video, all the parts are on Thingiverse.

[@wesleymoraisdesouza7436]

Actualy my DIY printer runs with a standard lm10uu + ptfe ones. In my case the ptfe ones solve the lm10uu backlash

[@chloemcholoe3280]

I never had luck with 3d printed bushings. but I'm gonna try for science :D either they lock up during certain angels or moves or they're way too lose.

[@CoderTronics]

If you do probably best to use a Delrin or Acrylic rod as the PTFE wore down after a few weeks of testing and also exhibited creepage. They should work much better on a Z axis as less pressure on 1 side compared to the X and Y, some rests of the testing are discussed in the comments of the Thingiverse link.

[@chloemcholoe3280]

@@CoderTronics aww those are impossible to find here! not to metnion i'm worry they'll bend under my heavy Y carriage and X carriage

[@balexfox]

It's amazing idea thank I will test this

[@-Gunnarsson-]

Accuracy and durability is the question

[@vdubs4life1964]

brilliant!

[@piezaspararobotica]

Muy interesante,,lo probare...Saludos

[@har2191]

nice!!!!!

[@daveyhi3154]

Wow that's a great idea! I'd suggest changing the title as otherwise the vid looks like a vid about the usual printed bearing.

[@CoderTronics]

Fair point have added a little bit to the title

[@abrahanmora9306]

ingenious idea

[@user-rd3lj4gn4s]

What diameter have transparent filament, which you insert in bearing? 1.75mm?

[@ordnanceant]

It's not filament they are PTFE rods, Acrylic rods would be more durable though. The diameter of the rods were 4mm

[@user-rd3lj4gn4s]

@@ordnanceant it is inpossible to be 4mm. In 8mm hole not you can insert many of them. If it is PTFE roads, then 2.2mm.

[@CoderTronics]

@@user-rd3lj4gn4s www.thingiverse.com/thing:1739340

[@forrestallison1879]

wow, how are these holding up now? still using the original ones? Super interesting design

[@CoderTronics]

I tested some solid PTFE (4mm rods) variants over 3 months on the Y axis, over time they did wear due to the weight of the carriage etc, you can see a similar set used on the 3D printed carbon fibre camera slider I made. I think PTFE will be fine for the Z axis as a more even all round pressure on the rods. When I have time I have some 4mm Acetal rods I want to test as these should be more robust, but my printer is currently in storage.

[@baselsalam]

So just print in PLA? Cant wait to try it out for my i3 (Malyan M150). I'll probably print all the sizes 8.2/8.3/8.4, then disassemble the linear shafts to see which one fits :) Or is it quite quick to take out a shaft, try, put it back, print.. repeat?

[@CoderTronics]

it won't hurt to print the samples first and see what accuracy you are getting with your printer, then maybe looking at loosing a rod to check and see. I actually had a spare 8mm linear rod lying around for initial testing. Think about filling the PTFE tube with household silicone, this should help stop the tube being compressed.

[@daveyhi3154]

Let me know how that works out :-)

[@caseycraig633]

I think that the rods on my x axis are 6mm. Is there a 3D model on Thingiverse that I could print for that size rod that acetal rods would still work with?

[@caseycraig633]

Do you have a link for these prints on thingiverse?

[@SergeDzus]

Отличная идея!

[@user-rd3lj4gn4s]

А разве втулка выполненная из PLA будет скользить хуже?

[@caseycraig633]

So you printed the green bearings? Where did you get the Teflon tubes?

[@CoderTronics]

Hi, from a company in the UK www.directplastics.co.uk , I would use Acetal though as harder wearing, the PTFE rod should be ok for the Z axis as the load is not biased to one side. This company sells the Acetal rods, as well as other plastics and very cheap,even after postage.

[@caseycraig633]

What filament type did you use to print the bearing? And how do I know what size rods to get? Sorry for the 20 questions. I’m pretty new at this.

[@333donutboy]

This a great idea. Is this something that you still use?

[@CoderTronics]

I used it for awhile with solid PTFE rods inserted (4mm), but these slowly were warn down. I intended to try with Acrylic and Delrin rods as much harder, but printer has been in storage since 2018 so just not had the time. We have a house now so intended to get a workshop going again in the next year and will test them.

[@333donutboy]

@@CoderTronics I made a version of this yesterday where the bearing are built into my x carriage (HEVO). I used 4mm PTFE tubing I had laying around. It slides a little snug but the steppers don't have an issue. I'm thinking at some point making a super cheap laser engraver. I think that this technique with some carbon fiber arrow shafts would make a decent axis. Appreciate you sharing this idea and look forward to some more testing. I'm subbing so I don't miss out.

[@CoderTronics]

@@333donutboy no worries, my printer is direct drive and quite a heavy head assembly, for a laser cutter if you can keep the head weight down it will probably work better, you will probably find the PTFE will wear eventual but can be pushed out and replaced potentially.

[@fogcc1015]

where do you find ptfe ???

[@CoderTronics]

Try here: PTFE www.directplastics.co.uk/ptfe-rod/ Acetal www.directplastics.co.uk/acetal-rod/

[@fogcc1015]

ok, but i live in France.... thanks for your answer

[@junang3]

Coaxial cable should have PTFE insulator on the center wire. Ex: www.awcwire.com/FAQ-PTFE-Coaxial-Cable

[@chloemcholoe3280]

litteraly any 3d printing store

[@junang3]

Coaxial cable should have PTFE insulator on the center wire. Ex: www.awcwire.com/FAQ-PTFE-Coaxial-Cable