Hi Michalko. Well, the bearings worked so far goodly: it would be a load of convergent circumstances which had many components wrecked in cascade. Anyway, now they are lubricated: wondering whether this might now solve eventual isses due to their overwearing. Perhaps the belt/cog may be another culprit. Though it is weird that the issue begins to appear always at the same moment of the printing and endures when I start a new print immediately over the former. I'll match the rest when I'll be back: the ideal had been if I'd been able to match how the coggery works with open case, but the covering is another joy&woe of this printer.
Ok. I've put in the fimware which finally the jg guy sent to me and put again the y vref to original state. The result didn't changed. Then I even removed the tl-smoothers, 'cause I suspected that it was matter of one of the two tls (I mounted 'em just to x and y axis) which was eventually burned, but and the result actually worsened: perhaps the smoothers nay smoothed also the problem! We did some footage of the inside and saw that the belt faltered (or, better, the stepper, I guess) more visibly than before: also the result is worse than previously, with double banding of the trails since the very beginning of the print.
Hi, That we can add some oil on the x rod and y rod, that may help for the move smooth. thank you so much
Second reply:
Turn off the machine, then move the x axis and y axis by hand, to
see if it can move smooth, if not, maybe the bearing is broken, we can
change it, thanks
Tried the print: the printing now was better (the y vref was at 5,7), since the perimeter of the first square, printed with a continous line instead of a double/triple shifoed concentric trail: the problem began to appear just since the minute 5,30 and continued gradually worsening for all the rest of the print, consisting in the diagonal filling movement invading the square perimeter, instead of not touching it. With time the rumor became more frequent and the faltering appeared more evident even. Placing finger upon the bed when homing after print stop, the bed faltered and "poprcorned" visibily. I sincerely cannot guess wtf is going on: nor is the "expert" of jg, who insists in saying that "maybe" is the bearing on the x or y axis... All of sudden? 3 years ownership and didn't appeared so far. And why the issue showoff just after a while instead of since beginning?
s the Y motor making clicking sound?If yes and your Vref voltage on Y stepper is set to 0,7Volts, you have mechanical problem with axis. It has not enough power to move bed. You are printing very slowly, so no ACC or JERK settings can be wrong.
Factory bearings are made from butter, instead of hardened steel. Also your Y noise is very noisy.
Can you move bed completely in front and while homing try to push it from backside of printer with fingertip? Will it start skipping?
I don't know if it is the y-stepper properly (no way to ascertain, with closed case): it is sure anyway that the click and faltering is from the bed ensemble.
The vref of the Y is set at 0,57. This is within the vref range of 0,4 / 0,6 that it is recommended in the page of the vref tuning which you linked. What should be the setting instead?
I'm printing at 50% speed.
I bought anyway other bearings today: they will arrive next month's end.
The shaft was oiled with lithium spray, but the bed now looks harder to push.
Hi Sam. I have a level of that kind. I'll do the test asap.
Anyway, if really the problem is only mechanical and related to bearings (or shafts, or what else? I'd had a wire camera!), I don't understand why it begins each time whilst doing the same operation (the diagonal filling: the timing at which it begins variates, from the middle of printing to the first 10-20 lines traced), and persists until the after-stop homing action, persisting also when initializing another print shortly after the one already stopped (in whih case, the issue appears since the beginning of the printing, when tracing the perimeter).
I'm a bit confused by what you mean "it began". Did the bed slip all the way to the front, when at 13 degrees? Perhaps a video of some kind would help.
The bed began to slip slowly towards the front of the printer when the raising was at 11-13 degrees, and it completely arrived to the front end when I went at 27 of slope (the more it sloped, the faster it slipped, obviously). I tried a video but it is not easy to do.
So at 13 degrees it stopped part way? Please help us understand what happened exactly. There is a big difference between 13 degrees (low friction) and 27 degress (very high friction)
It is not easy to raise the machine instantly at a given angle at once. Btw, which angle? That way it wouldn't be clear even which angle is the one at which start the bed starts to slope the way it would slope in order to ascertain what's going on with it. Sure that, remaining at 13°, surely it hadn't moved until the front of the printer: but I cannot guess whether it had stopped at a certain point, if remaing at that angle.
Yes, it began to move at 13°: I didn't mind if it had to stop partway, 'cause I continued to raise the tail until the slope reached 27°, in order to have it moving faster.
I am not sure if this will help but I recently had an issue that had the same symptoms. And, the resolution was completely mechanical. I should first say this is on a A3S and you will know if you have this problem because you will have rubber particles from the y-axis belt inside your housing.
The y-axis became very stiff. With power off, the print bed would not slide easily. When I opened the printer I found a lot of rubber particles from the y-axis belt in the bottom of the housing. I removed the table so that I could thoroughly inspect everything. What was obvious was that the y-axis belt was rubbing inside the front bearing (top side). The top side of the belt was frayed (as you can see in the photo (photo appears upside down because I have the top of the housing flipped over).
The bearing mount had apparently shifted ever so slightly and was not parallel to the end mount. You can see in the attached photo I put a flat screw driver behind it and adjusted the alignment ever so slightly and it instantly corrected the problem. My fix is a shim in behind the bearing mount (difficult to see in my photo but it is a think brown part in behind the mount).
Sorry, accidentally posted before I added these photos to previous post.
Above photo shows small brown shim in behind the bearing mount. This solved the problem and it has been operating for some time well. Why the bearing mount became out of alignment is the real question and I do not know the answer.
did you suceeded?I do not see any further progress from you. What pdb6251 describes is common issue also on A5. These days one of my colleagues asked me for help with his printer. Same issue=Y axis skipping. 2 issues found. One bearing bad and belt TOO TIGHT. You should be able to touch both sides in middle by gentle force. If it is too tight, motor does not have enough force plus pitch of teeth will slightly change even if there is kevlar or steel wire inside
Hi. I thought I described what happened with sloping the bed: I figured any opinion on what might happen according to what I described.
I didn't modified yet the holder distance: the guy who helped me got a bad on one knee and I'm alone and I cannot peek at the printer now. Anyway it's not clear if I have to substitute the belt also (I bought a set of bearings anwyay).
I found an help and maneuvered the modifies. I added a spacer to the tensioner, but nothing changes. My clue is: if it is just a mechanical problem, why it does appears always during the same moment of the printing, instead of randomly? A second clue is: how it is possible that, with time, the belt becomes tighter instead of loser? And, how a worn bearing could affect the movement always in the same point of the printing?
Update: I losened the belt, and the problem appeared since the tracing of the perimeter. Now I try with tightening the belt much more than the previous state.
Update: with tightened belt, the problem persists anyway. The rumor now is more clearly perceived as coming visibily from the spot where the y stepper is located. Perhaps the stepper is broken and we are searching the solution elsewhere? And, it is the stepper broken, or the belt mangled or the cog teeth smoothed?
hmm. Steppers do not die very often. At least I did not saw broken one yet. There is only possibility of broken bearing or both inside steppers, but not a high chance. So did you found spot where this skipping happens? When you slide bed by hand, can you hear different sound of mechanics in that place?
Do you know program called Pronterface? You can connect printer via USB cable to PC and control it completely remotely. You can try to move axes by sending command to it a and observe behavior.At first select correct COM port. Printer will create new one-you can see it in device manager, or blind checking it by finding from available ports in Pronterface drop down menu. Click Connect and on right side you will see printer EEprom parameters appear. change speed of XY to 3600mm/min, which means 60mm/s. This shall be your normal printing speed with direct drive(I have bowden setup and my printing speed is 55mm/s). Press home button-right lower side of circle. After finished, press +Z 10. This will raise gantry up by 10mm. Then you can move Y in 100mm steps by clicking on portion of circle marked by distance. Observe motion and sounds of movement.
Comments
Factory bearings are made from butter, instead of hardened steel. Also your Y noise is very noisy.
Can you move bed completely in front and while homing try to push it from backside of printer with fingertip? Will it start skipping?
The y-axis became very stiff. With power off, the print bed would not slide easily. When I opened the printer I found a lot of rubber particles from the y-axis belt in the bottom of the housing. I removed the table so that I could thoroughly inspect everything. What was obvious was that the y-axis belt was rubbing inside the front bearing (top side). The top side of the belt was frayed (as you can see in the photo (photo appears upside down because I have the top of the housing flipped over).
The bearing mount had apparently shifted ever so slightly and was not parallel to the end mount. You can see in the attached photo I put a flat screw driver behind it and adjusted the alignment ever so slightly and it instantly corrected the problem. My fix is a shim in behind the bearing mount (difficult to see in my photo but it is a think brown part in behind the mount).
Above photo shows small brown shim in behind the bearing mount. This solved the problem and it has been operating for some time well. Why the bearing mount became out of alignment is the real question and I do not know the answer.
Do you know program called Pronterface? You can connect printer via USB cable to PC and control it completely remotely. You can try to move axes by sending command to it a and observe behavior.At first select correct COM port.
Printer will create new one-you can see it in device manager, or blind checking it by finding from available ports in Pronterface drop down menu. Click Connect and on right side you will see printer EEprom parameters appear. change speed of XY to 3600mm/min, which means 60mm/s. This shall be your normal printing speed with direct drive(I have bowden setup and my printing speed is 55mm/s). Press home button-right lower side of circle. After finished, press +Z 10. This will raise gantry up by 10mm. Then you can move Y in 100mm steps by clicking on portion of circle marked by distance. Observe motion and sounds of movement.
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