RE: Belt tensioning issues - firmware tensioning guide and website tensioning "app"
The release candidate of the most recent firmware update was causing alot of collision detection errors and it took forever for a print to start; although the print worked out successfully.
This version of the firmware is out of RC so I'm hoping that the stable version address these issues.
RE:
Hey Butters,
I am on the stable (out of RC) version, 6.4.0. I hope everything works out ok for you now.
My additional problem with the tensioning screw turned out to be less severe than I thought and I managed to put things back together.
I started again from loose belts. The quick gantry adjustment just doesn't work for me and I didn't want to "push" too much so I just assume either my difference between end stops is too small or I have a crooked part somewhere ; so I skipped that step and went straight to step 3 and 4 here: https://help.prusa3d.com/article/adjusting-belt-tension-core-one-l-core-one_845048
So I just did that sort of combined with all the advice here; when my belts were very loose I:
- tightened both screws almost equally, tightening a bit more on the side with more play. For example 3 quarters (or a bit more) of a rotation on one side, 1 full rotation on the side with play
This didn't get me in the perfect spot so when my belts were too tight I:
- loosened both screws almost equally, loosening a bit less on the side with more play. For example one full rotation on one side, 3 quarters of a rotation (or a bit more) on the side with more play.
I randomly stopped at some point, re tightened the belts (in a similar fashion as above).
Somehow after this I got both the web app tuner happy and the manual belt tuner in the firmware (where no adjustments were needed). I re-ran input shaping calibration and phase stepping callibration, the values changed a bit and I AM NEVER TOUCHING IT AGAIN (joking, will surely do). Hope to get printing soon.
Thank you again to everyone in this thread
RE: Belt tensioning issues - firmware tensioning guide and website tensioning "app"
- tightened both screws almost equally, tightening a bit more on the side with more play. For example 3 quarters (or a bit more) of a rotation on one side, 1 full rotation on the side with play
Hi @cupu, if possible it's best not to do this. First you square the gantry (if needed) when the belts are loose by manually bending it with your hands. Then when you are tightening the belts, as long as you are tightening both screws by the exact same amount alternating between them, then the gantry should not bend or skew. If you try to re-square it by unevenly tightening the screws you can could possibly cause more issues later.
RE: Belt tensioning issues - firmware tensioning guide and website tensioning "app"
Hey hyiger,
Thanks for drawing attention to possible problems later. I will muster up some courage and try again in a few days.
RE:
Hey hyiger,
Thanks for drawing attention to possible problems later. I will muster up some courage and try again in a few days.
Prusa had instructions (at some point) to remove skew in the gantry by changing the belt tension (turning the screws) but the current state is to ensure the gantry is square before tensioning the belts. When you've done it once or twice it becomes pretty routine. Also, it's a good idea to recheck the tension every once in while. Like checking the air in your car tires.
RE: Belt tensioning issues - firmware tensioning guide and website tensioning "app"
That's good advice about checking tension now and then, I've set a reminder in my calendar to check in 3 months.
I do not believe my gantry can be squared without any tension in the belts. I've tried many times over the course of this forum post. I am afraid that the only thing left to do is put more force into "fixing" the loose-belt gantry and I will break something. Maybe I have a part that's not exactly at a right angle or something ; I don't feel like taking the printer apart. We'll see if that is a mistake or not.
RE: Belt tensioning issues - firmware tensioning guide and website tensioning "app"
That's good advice about checking tension now and then, I've set a reminder in my calendar to check in 3 months.
I do not believe my gantry can be squared without any tension in the belts. I've tried many times over the course of this forum post. I am afraid that the only thing left to do is put more force into "fixing" the loose-belt gantry and I will break something. Maybe I have a part that's not exactly at a right angle or something ; I don't feel like taking the printer apart. We'll see if that is a mistake or not.
The two brackets that attach the gantry to the Y axis bearing are not always at 90°. They are also made from mild steel and are not difficult to bend. With the belts completely loose, if the skew is to one side then grab both sides and bend the other side by hand until it is square. It doesn't take much pressure. However, unless you go caveman on it you won't break anything.
As for checking the belts I do it irregularly at about once a week or so.
RE:
Simple... Fix the gantry by bending it, it's even in the instructions (do read them, and don't apply force to the gantry without loosening the belts or you may rip out an idler pulley).
I hate to break the bad news but you do have a part that is not exactly at a right angle. That "part" is sheet metal (a pair of symmetrical parts, actually, where the error cancels out, ideally. Not necessarily in reality though).
Bend the gantry in shape with belts off (doesn't require "violence" just controlled use of moderate force), then double-check it's still orthogonal under tension and fine-tune screw balance until aligned again.