Bearing play - Is this normal?

I was just looking over my new-ish TAZ 5, and reseating the extruder. In the process I noticed there is a fair amount of play in the x bearings. I’m including a video. Is this normal?


It’s sad, but yes, normal… The bearings are meant to be pressed into a press-fit bore. You can’t apply the needed pressure with a slotted ABS bracket, thats why there is a lot of play in it. A design flaw in my optinion… :cry:
But nevertheless, it will print good parts. Gravity is the reason why you will not see the play in your prints as long as you are not going too fast.

I tried printing a press-fit bearing holder. With try and error, I got the necessary diameter, resulting in a smooth, play free bearing. But there is one problem: It’s only possible to print single bearing holders, because if you try to print a 2 in 1 like on the Z-axis it will be clamping on the axis due to minor alignment problems due to the printing process.
I also tried printing it horizontal, but then the press-fit forces will split the layers appart.
The only real good solution would be a metal bearing holder with propper tolerances…

It looks like they are considering injection molded bearing holders for the next gen Taz. Hopefully that will allow enough compression to solve the problem.

Good points all around!

I wonder if it might be possible to use the stock extruder mount, but add some kind of clamp to squeeze the part that holds the bearings?


My Mini does that on the Y axis… drives me nuts

There is a version of the bearing mounts that use a m3 screw for adjustment on I tried something similar, i wasn’t satisfied. You are squeezing the beating out of shape, that eleminates the play only in one direction. I’m not sure how to explain it in English. Instead of a contact surface all around the rod, you get a line contact on 2 sides of the rod.

I am a bit puzzled about the blaming of the mount. The IGUS bearings they used are not a tight fit and you can’t squeeze them to fit (they are extremely rigid).

I replaced my 3 X-carridge ones with some that are very close tolerance (yet expensive at around $13 ea.) made by PBC Linear. I am trying to order more now for the rest of my machine.

If you put an IGUS bearing on a rod by itself it will rattle all over the place (tons of slop) when I did this with my new bearings I tipped the rod from horizontal (not in the machine) to vertical and it slowly slid down the rod while the original one just dropped like a rock.

My X-axis has been more accurate since I have been testing these bearings for 6 months now and that is why I will be upgrading the rest of my machine as soon as I get some more in.

If anybody is interested the bearings I chose (after talking with them) was the FJC10

Read the spec about the igus bearings about tolerances and the force that should be necessary to press then into the bearing holder. Also read about the final tolerances between shaft and bearing after the press fit and compare them to the huge play on a TAZ.
You can deform them…

Don’t blame the manufacturer of you don’t use their parts as planned :wink:

Thanks for the tip on the PBC bearings. I have been fighting the looseness and ripples caused by the IGUS bearings for a couple years now. I am getting ready to do piercet’s openbuilds update on my Taz 2 but these bearings might solve a lot of problems on my Taz 5 machines. :smiley:

I have some good news! Some background first…

Like many of us, I replace the stock plastic X & Y bearings and soft steel shafts with Misumi linear bearings and hardened steel shafts. I was not satisfied with the results and had severe rippling on large horizontal surfaces of my parts. The linear bearings rumbled and I figured it was resulting in harmonic vibrations that resulted in surface ripples. (Seems this was true)

So, I ordered sintered bronze bearings from Amazon (10mm ID x 14mm OD x 25mm L). I printed some ABS sleeves to place the bearings in to bring them up to size and just installed them on all three axes. The results are amazing! The ripples disappeared, the bed seems to move with less friction, and the printer is much quieter. These new bronze bearings cost me only $50 with shipping. Another positive is that these bearings should work fine with the stock shafts - no hardened shafts necessary. I’m expecting the bearings to last forever; a drop of oil every coupla months on each shaft (if that often) should do it.

The plastic sleeves are 2-part with a light press fit for the bearing. The two parts overlap a bit and a drop of acetone cements them together. See the photo of the plastic sleeves, the bronze bearing, and a bearing/sleeve assembly.

I can’t describe how pleased (and relieved) I am with this upgrade.
Sleeve Bearing Parts.jpg

Thought I’d offer an update. It’s been about a year and a half since I installed the sintered bronze bearings and they are working as well as new. No apparent wear.