This is for anyone that has upgraded their TAZ with hardened rails and bearings…
What bearings did you purchase and where did you source them? Do they run nice and smooth for you? How do you oil / grease them?
I went with Misumi bearings and rails and have found the bearings, especially on the Y axis to run a little rough. The roughness translates to a stippling or texturing on the side wall of my parts when the Y axis is moving.
I am going on the assumption that this is caused by a bearing problem. If anyone has other ideas, I would love to hear them.
It is difficult to get a good picture of this but here are a couple of examples. You can see the problem more clearly if you view the full size image.
X axis is nice and smooth as it should be.
Y axis has this odd textured look.
I just recently got the linear bearings from jsb website (link below), ordered about 10 (incase I get a few bad ones) and the hardened rods from mccaster website.
The bearings were already lubricated along with the rods.
I moved the linear bearings on the rods several times to make sure its very well lubricated and it was moving freely. I only installed it on the Y axis only for now. I only printed out a circle calibration and it turned out just fine.
I have read on the reprap forum that some use white lithium grease on their LM bearings. Maybe I will give that a shot.
I dont think that was lubricant. Its an anti-rust oil. Thats what the misumi specifications said when I looked them over for the bearings
Update on this. I removed all the Misumi bearings, cleaned them out and re-lubed with lithium grease. No change in print quality.
I have ordered new bearings from VXB. I will post results once those are installed.
I am also wondering if this problem could be motor jitter rather than a mechanical problem.
Just to update this.
I have moved back to the Igus bearings on Y due to the continued roughness generated when the metal bearings were installed.
I have tried three different sets of bearings. Amazon whatevers, Misumi and VXB. All were rough on Y. I have also tried light machine oil, Superlube aerosol, Superlube grease and the Lucas lithium grease Lulzbot recommends for the lead screws. The lubes didn’t change anything.
After you replaced the IGUS bearings with linear, did you have difficulty securing the bearing holder to the aluminum plate? My linear bearings were slightly larger than what the bearing holders accepted so it made the part bow out slightly and that made it difficult for me to reinstall them. I ended up having to screw in two opposite corners and I used one of the stock rods to gently pry the bearing holder so that the other two holes would line up for the screw. I’m not sure if that’s what’s causing mine to have that funny pattern too. Also what speeds were you printing at?
I didn’t have any problems installing any of the bearings. They slipped right in. I actually had to wrap a few of them with PET tape to snug them up a bit.
I print at normal speeds. 50 - 80 mm/sec. Sometimes slower depending on the geometry of the object. I am shooting for better quality over faster.
So the Stock linear bearings are a plastic bushing? Your replacing with ball bearings which come in different grades and I suppose you know that already. Did you try finding the Linear bearings from a different vender?
I tried three different brands of bearings. Amazon no name, Misumi and VXB. Same results from all of them. Seriously, they all seemed to be the same bearing.
The stock parts are Igus polymer “bearings.” They are essentially a self lubricating plastic bushing. They slide smoothly but do not fit the smooth rod tightly. They tend to induce some rippling in the printed part. That is what I was trying to eliminate.
Piercet’s vslot rail mods are probably my next modification.
Ball bearings unless you spend a Lot of money like for precision surface grinders tend to be not as smooth as bushings. They come in various grades and I don’t know the details right off hand. Not sure if the same grading apply to linear ones?
I replaced my rods with hardened steel and installed ball bearings in all the bearing holders.
Is it normal to be able to move 1 of the 2 bearings in the holder? If I physically shake the holder, I can hear one of the bearings sliding back and forth.
I assume this is supposed to move a little bit because of how the holder was designed?
How snug should my bearings fit inside?