interaction between axis
just assembled the MK4S to CORE One conversion kit and I'm having this problem:
When I move the Nextruder on the X-axis using the screen knob, the gantry also moves a bit (see attached video). This interaction between X and Y makes it impossible to calibrate X and Y.
Any suggestions on what I've done wrong?
RE:
Have you installed the pulleys correctly on the X and Y motors? One needs to have the toothed part on top, one on the bottom end, so they properly engage with the belts. It is a common trap to install the second one "on autopilot", the same as the first -- but it needs to be the other way round.
Or the screws which lock the pulleys to the motor axles might be loose on one side.
RE: interacción entre el eje
Indeed, the Y motor pulley was reversed and now that issue is gone — it moves perfectly in X and Y using the button, but it still won’t calibrate. In fact, after changing the pulley position, it did calibrate correctly once yesterday, but today, the auto-homing keeps retrying and never finishes.
I’ve performed all the checks from the manual: I verified that the gantry touches both end stops simultaneously, and it does. Then I adjusted the upper belt tension to 98 Hz using the left screw, but when I adjust the lower belt to 92 Hz with the right screw, I see that once the lower belt is at 92 Hz, the upper belt frequency has dropped. In other words, both screws affect both belts and there is no way to keep one at 98 Hz and the other at 92 Hz — adjusting one throws the other out of tune.
I’ve gone through everything the manual says and everything seems correct, and I honestly don’t know where else to look. After 10 years building printers, this is the first one that gives me such a massive headache and I really need help.
Thank you.
RE:
Indeed, the Y motor pulley was reversed and now that issue is gone — it moves perfectly in X and Y using the button, but it still won’t calibrate. In fact, after changing the pulley position, it did calibrate correctly once yesterday, but today, the auto-homing keeps retrying and never finishes.
I’ve performed all the checks from the manual: I verified that the gantry touches both end stops simultaneously, and it does. Then I adjusted the upper belt tension to 98 Hz using the left screw, but when I adjust the lower belt to 92 Hz with the right screw, I see that once the lower belt is at 92 Hz, the upper belt frequency has dropped. In other words, both screws affect both belts and there is no way to keep one at 98 Hz and the other at 92 Hz — adjusting one throws the other out of tune.
I’ve gone through everything the manual says and everything seems correct, and I honestly don’t know where else to look. After 10 years building printers, this is the first one that gives me such a massive headache and I really need help.
Thank you.
Need to be very careful adjusting the belt tension, otherwise the gantry can get bent out-of-square. This is probably why the Y calibration is failing. You are correct that both screws tension both belts. So they have to be turned evenly. If you turn the first screw 1/4 of a turn then you must also do the same on the second. Don't try to get the belts exactly 98/92 trying to do so you can easily get gantry bent.
First, completely loosen both pulleys so the belts are slack. Then move the gantry to the front of the frame and check if it is still square. If it is not then physically bend one side slightly until it is. Then when tightening the belts you must turn both screws evenly. So left 1 turn, right 1 turn etc. Once the belts are getting within range, then tighten left 1/4 turn, right 1/4 turn, then 1/8, 1/8 etc. Never tighten just one screw and not the other or tighten them unevenly or you could possibly bend the gantry.
If both belts are in the mid-90's, that is good enough.
- Bob Marley
RE: interaction between axis
Then I adjusted the upper belt tension to 98 Hz using the left screw, but when I adjust the lower belt to 92 Hz with the right screw, I see that once the lower belt is at 92 Hz, the upper belt frequency has dropped. In other words, both screws affect both belts and there is no way to keep one at 98 Hz and the other at 92 Hz — adjusting one throws the other out of tune.
I’ve gone through everything the manual says and everything seems correct, and I honestly don’t know where else to look.
Not sure whether the build instructions have been updated as well, but there is a new help page on the belt adjustment. It acknowledges the interaction between both belts and provides adjustment instructions accordingly. Maybe that page is helpful: https://help.prusa3d.com/article/adjusting-belt-tension-core-one_845048