I have a question about the smoothness of the x and y carriages.
How smooth should be?
For instance should it be so free that it will slide if you tilt it ?
Mine isn’t stiff but does seem to have a bit of inertia, you can’t push it a couple of millimeters very easy, sliding back and forth is somewhat fine, not as good as I was expecting, but is this as good as it needs to be?
Seems to slide a little better if you apply some radial load to the bearings.
I did receive one 8mm bearing which was a little worse than the others, so I bought some more from eBay hoping that those would be better but they performed almost identical to the ones supplied. I did the same for the 10mm bearings, the additional ones I bought felt the same as the Velleman bearings.
I guess what I was expecting was something akin to the feelings a drop-saw has when you push/pull it in and out. Is this what we are looking for on the x and y carriages.
Has anybody purchased “brand name” bearings for their unit with a noticeable increase in smoothness?
The carriage should slide easily if no belts are attached.
Ideally the move when the printer is tilted at about 30 degrees.
But that is almost not achievabla i think.
The bearings are quite cheap.
Mine didn’t run very smooth at first too.
It helps to put grease inside the bearings before mounting them.
I also let them run full length X and Y at max travel speed for about 200 times with a g-code script.
That made them run somewhat smoother.
Without the belts attached the carriages should slide freely when tilting the printer (at least that’s what mine do).
I exchanged the linear bearings of the Y axis with brand bearings, as I thought it might get better.
The effect was 0.
Make sure the bearings are absolutely parallel. Slide the carraiges back and forth with loosend screws, oiled rodes and tighten carefully without twisting the bearing mounts.
[quote=“Deskstar”]
Make sure the bearings are absolutely parallel. Slide the carraiges back and forth with loosend screws, oiled rodes and tighten carefully without twisting the bearing mounts.[/quote]
That would be the most tricky part i think.
I i remember correctly someone put other mounts for the linear bearings on thigiverse, where the bearings are not
as tightly clamped as in the original mounts. That might help, but i didn’t try yet.
Just a small update on this issues, which I sorted sometime back but forgot to post it for others to read.
I found my Y carriage plate was bowed, placing a straight edge across it showed a bow in the center, so when tightening the screws the bent plate was pulling some bearings more than others giving me a very stiff carriage.
To get around this I found the strongest foam double sided adhesive tape (3M branded) and cutout and stuck this between plate and all four bearing holders and tightened the screws with thread-locker as much as I could before it bound up again.
I attempting cutting plastic shims to correct this but, it was very tedious.
I also tried a layer of 1mm foam between each bearing holder and plate,(worked equally well as the d-side tape) but in the end went with the double sided tape.
I’m unsure of its longevity yet as I haven’t finished the build, I’m finding a lot of misshapen parts and do not wish to wait for replacements
I would have straightened the Y carriage (too) in your place.
I found out if you tighten the X belt clamps too much this will also bend the y carriage.