Iglidur bearings

Hi,

Anyone out there tried to print his/here own bearings..?
Can't seem to get it right. I've tried but the bearings are not perfectly round. A small error remains, about 0.1 to 0.17mm off roundness.
Checked everything, also whether X and Y are perfectly 90°. (RepRap printer - very sturdy)


Tips..?

Chris

I would always use a reamer to bring the diameter to the precise size.
Be careful though, i found printed iglidur bushings a bit brittle.

Edit: Removed typos due to hand injury

Edited 1 time(s). Last edit at 03/24/2016 10:10AM by Srek.

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[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

Hi Srek,

Is not working, a reamer is to small.
I drilled the hole a little larger, 8.1 mm instead of 8.0 mm and it works perfect, even a better fit compared to the metal linear bearings.
The only solution to make(print) perfect bearings is print smaller holes and larger outer perimeters. Afterward adjust the two diameters with a drill and then in a lathe the outer diameter.
Still don't understand why these printed bearings are not perfectly round.

Chris

Out of round can be caused by backlash and incorrect steps per millimeter.

No offence but before I would try to print a bearing in nylon or similar I would simply use teflon rod and put it a lathe....
From a bearing or bushing you want tight tolerances and low friction.
Teflon offers this with no lubrication at all, althoug I add a drop of silicone oil to keep the dust out.
I tried printing some bearings in nylon and came to the conclusion that the print direction needs to be considered.
You want the sliding direction to be the same as the last infill direction.
Also most designs I found online are just copies of real bearings and bushings without consideration of the difference between printed and extruded/machined.
If I have to print a sliding bearing (large diameter teflon rods are expensive) than I design it like a clamp.
Meaning I have two halfs of the round part that are connected to the mount.
On the opposite end they are a bit longer and with two screw holes.
The diameter is selected so print margins and tolerances end up with a part that is just a hint too big - the final adjustment is done with the screws.
I found this design to be more reliable and longer lasting than standard designs.

Another option for easy-repair bushings and sliding bearings is to cheat
Take some BBQ liner (the non stick teflon stuff) and measure the thickness.
Take you favourite designs for a bearing and make room for the liner.
You want to remove about half it's thickness but leave some material on the outside to make sure the liner stays in place - like a rim.
If one day the firction is too great or the liner is worn you cut another one and put it in without the need to print a new part - plus you get far less friction than you would get with a printed part.

Have you ever calibrated the printer?
Have you ever checked orthogonality of the axes?

You calibrate by printing an object of specific dimensions then measure the object and make corrections to the steps per mm settings. Check orthogonality by printing a square or rectangular object and measure it's diagonals. If they are the same the axes are orthogonal, if not, they aren't.

If there is slop in the machines bearings, as is common when using bushings, printed or other, your machine may not be capable of printing round objects or holes accurately. Bushings and bearings are critical parts in a printer as are so many other parts. If you intend to print accurate and precise parts with your printer, I suggest using something better than printed parts in critical areas like bushings. While 3d printers can make a lot of different things, they can't make everything.

I know that maximizing use of printed parts in a machine follows the reprap philosophy, but that philosophy is about quantity, not quality. Machines printing machines is a nice idea that quickly Falls apart in practice. It's like using a cassette tape to make a copy of a cassette tape. After a couple generations of copies, the original content becomes nothing but noise and distortion. If you try to print parts for 3d printer using a sloppy printer, how well will that second printer work? And if you use the poor copy to print more parts for more machines, how do you think those machines will perform?

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
the_digital_dentist
Have you ever calibrated the printer?
Have you ever checked orthogonality of the axes?

You calibrate by printing an object of specific dimensions then measure the object and make corrections to the steps per mm settings. Check orthogonality by printing a square or rectangular object and measure it's diagonals. If they are the same the axes are orthogonal, if not, they aren't.

If there is slop in the machines bearings, as is common when using bushings, printed or other, your machine may not be capable of printing round objects or holes accurately. Bushings and bearings are critical parts in a printer as are so many other parts. If you intend to print accurate and precise parts with your printer, I suggest using something better than printed parts in critical areas like bushings. While 3d printers can make a lot of different things, they can't make everything.

I know that maximizing use of printed parts in a machine follows the reprap philosophy, but that philosophy is about quantity, not quality. Machines printing machines is a nice idea that quickly Falls apart in practice. It's like using a cassette tape to make a copy of a cassette tape. After a couple generations of copies, the original content becomes nothing but noise and distortion. If you try to print parts for 3d printer using a sloppy printer, how well will that second printer work? And if you use the poor copy to print more parts for more machines, how do you think those machines will perform?

All parts of my printers are my own.
Meaning, I took a reprap as example and redrew every part. I ignored the slimline-idea that many developers used and made all parts stronger and stiffer. So this is a 'first-generation' printer and not a copy from a copy.... I also (literal) bolted the printers to the walls of a very sturdy cabinet.
All adjustments have been done thoroughly, spent many hours doing that.
This is the one.
[www.thingiverse.com]
To be clear : this concept is not my idea at all, I only renewed it.
I also added fast removable extruders and cooling for the parts.
The fast removable extruder is bolted down, so is fastened very good to it' s carriage. No loose parts at all.
There is no play anywhere at all, except for the linear bearings maybe. Chinese rubbisch...? Anyway that's why I want these bearings to be replaced by selfmade bearings.

But I think I will go for the solution mentioned higher up : to small hole and to large outer diameter printing and afterward reaming-drilling the hole and make the outer diameter smaller in a lathe.

Chris

Have you considered linear guides? You won't find better bearings, and fully supported rails are much less flexible than end supported rails.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
the_digital_dentist
Have you considered linear guides? You won't find better bearings, and fully supported rails are much less flexible than end supported rails.

As a matter of fact, I was busy drawing this type of bearing. Not exactly the same but about.
At the same time I would use 12 mm(or even thicker) smooth rods instead of 8 mm in the setup I'm using now.
Around these thick rods and self-made bearings I will draw a complete new printer. In the first place I'm thinking : vibration free and no play, or at least as good as I can possibly make it.

Chris

If you really beef everything up then you should not take shortcuts with printed bushings and bearings.
For real precision you simply need steel and not plastic.
Sure it is fun and it will work for a while if you are lucky but in the long run you will constantly adjust and calibrate for the problems caused by the printed bearings.
Check an old laser printer or a really old inkjet printer against their modern counterparts and you know why the old ones would still work fine today.
Especially if you desire higher print speeds you will value proper bearings and bushings sooner or later

Quote
chriske

Quote
the_digital_dentist
Have you considered linear guides? You won't find better bearings, and fully supported rails are much less flexible than end supported rails.

As a matter of fact, I was busy drawing this type of bearing. Not exactly the same but about.
At the same time I would use 12 mm(or even thicker) smooth rods instead of 8 mm in the setup I'm using now.
Around these thick rods and self-made bearings I will draw a complete new printer. In the first place I'm thinking : vibration free and no play, or at least as good as I can possibly make it.

Chris

I started with 1/2" end supported guide rails and quickly came to the conclusion that they were too flexible. That was before I knew about linear guides. Now I would not build a printer without them.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
Downunder35m
If you really beef everything up then you should not take shortcuts with printed bushings and bearings.
For real precision you simply need steel and not plastic.
Sure it is fun and it will work for a while if you are lucky but in the long run you will constantly adjust and calibrate for the problems caused by the printed bearings.
Check an old laser printer or a really old inkjet printer against their modern counterparts and you know why the old ones would still work fine today.
Especially if you desire higher print speeds you will value proper bearings and bushings sooner or later

There's a lot of truth in that post I'm afraid...

still...printed bearings should work fine according to this YouTube movie:
[www.youtube.com]
Not just any filament can be used of course. I'll use filament developed especially to print high quality bearings.

Hmmm, are we talking about some new high tech filament I missed?
The bearings in the video are specially designed materials in a combination to make them work for the purpose.
A printed bearing will always just be a piece of simple plastic.
I admit that for some time and on a 3D printer it might work similar to door hinges.
But if want a printer capable of less than 01mm of accurate movements, high speeds and possibly some weight due to heated bed and other stuff, then plastic is no option IHMO.
Those high tech tings will work for sure but a printed one won't survive for long.

Quote
Downunder35m
Hmmm, are we talking about some new high tech filament I missed?

Maybe you did. The Iglidur mentioned in the title is the material Igus uses for their bushings, it is available as filament.
I did some succesfull tests to use it for printed bushings.

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[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

Quote
Srek

Quote
Downunder35m
Hmmm, are we talking about some new high tech filament I missed?

Maybe you did. The Iglidur mentioned in the title is the material Igus uses for their bushings, it is available as filament.
I did some succesfull tests to use it for printed bushings.

There is only one drawback.
In the reprap (and some other)printers bearings are often 'locked down' with tie-wraps. The printed 'Iglidur bearings' can't withstand that kind of locale pressure. Using tie-wraps the bearing is deformed a bit and lock itself on the axis. We tested it.
You need another way to attach these bearings to its parts and see to it the bearings are not squeezed in one or other direction. I think of a half counterpart to gently hold the bearing in place would work.
Another point : When a Iglidur bearing is pressed with a bit of force in a hole, the hole of the bearing itself will get a fraction smaller, so you need to ream or drill it a last time before you can insert the axis.

I actually did not try to print single bushings but printed the iglidur directly in the functional part of a printer.
I agree, printing iglidur bushings as replacements for other bushings or bearings will pose some problems, but if you design printer parts with iglidur contact surfaces in mind things work rather nicely. I am thinking about designing a variation of my DuoCube that uses this technique instead of bronce bushings.

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[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

If you have some spare rods around do some friction tests at various speed and load ratings.
A simple stepper motor with a belt.... you get the picture.
Gives you a chance to test the designs for a while for increased friction, abresion and stability.
Years ago the company I worked for made a machine for these tests for a bearing manufacturer.
One side tested linear bearings the other normal bearings.
You might be surprised to see that some plastics you can print perform quite differently than what you would expect.
Properly finnished PLA in low load setup works quite well for a long time, just keep speed and surrounding temps low.

Around $320/Kg is a bit off-putting. Srek's suggestion for printing it into specially designed parts does sound fascinating though.

It costs €40 per 250g. Since you only need a few grams per piece the actual costs are rather small. I would never print complete parts from it.

Edited 1 time(s). Last edit at 03/27/2016 04:21AM by Srek.

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[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

Good point. Another filament to go on the wish list - this is becoming an addiction!

To avoid tension and deformation during fastening the printed bearing in place, maybe it first could be pressed in a holder. Kind of a bearingblock, not to large, just large enough to put some small screws in it.
Additional advantage is the bearing block can be adjusted just a little bit.
PLA is very hard and stiff, that would do the job imo.

I just say it again: BBQ liner

Quote
chriske
To avoid tension and deformation during fastening the printed bearing in place, maybe it first could be pressed in a holder. Kind of a bearingblock, not to large, just large enough to put some small screws in it.
Additional advantage is the bearing block can be adjusted just a little bit.
PLA is very hard and stiff, that would do the job imo.

I designed an adjustable bearing block for Thomson super 8 1/2" linear bearings. You might easily adapt the design for this application. You can find it here: [www.youmagine.com]

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
Downunder35m
I just say it again: BBQ liner

Could you explain please what a 'BBQ liner' is.

Quote
the_digital_dentist
I designed an adjustable bearing block for Thomson super 8 1/2" linear bearings. You might easily adapt the design for this application. You can find it here: [www.youmagine.com]

Nice one... Gonna try it.
But I think it will flatten the printed bearing.