first layer down then she gos crazy
Tried to print a benchy, and she's moving so fast it shakes my floors, then each layer moves over diagonally!
Next, I tried a key chain, and the first layer went down, and then the print head took off to the bottom right side of the bed, squirting out PLA along the path.
The printer makes a noise like a belt slipping, or that could be the sound of the drivers moving extremely fast.
All my calibration tests have passed and I have looked at the best and see no issues.
RE: first layer down then she gos crazy
Egan, im having a similar issue. I've been trying to determine the cause but not having any luck. I noticed your post and thought I would add my experience as well. Perhaps someone can lend some advice.
My "attempted prints" are similar. My calibrations are successful and everything seems ok. The first layer appears good. When the print head starts moving very fast (quick movements between direction changes) I can hear what I assume to be a belt slipping. Tried both the default benchy and keychain prints from the provided models in the Prusa thumbdrive. I have my belts tensioned to 85hz for both x and y. I have tried slowing my print down to 80% and still the same symptoms.
Hopefully other can help provide some guidance and troubleshooting tips.
RE: first layer down then she gos crazy
Hi, I have the exact same behaviour. Spent some time in chat with prusa support without any improvement.
RE: first layer down then she gos crazy
Have you checked that the pulleys aren't slipping on the motor spindles? One of the grub screws should be tight against the flat of the spindle, to prevent them spinning, and the other should just be for additional grip.
RE: first layer down then she gos crazy
I will check it Chris Hill.
This is how my print looks.
RE:
So I did check the pulleys and I cannot tight them more. I attach a video of the issue, you can here the noise when the shift happen. I even tried to print another model, the keychain that comes in the prusa usb drive, the issue happened immediately and the print started on one of the corner.
RE: first layer down then she gos crazy
I struggled with Prusa's belt tuner on my XL. Using the 3D printed tension-meter-for-the-gt2-belts from Prusa was more consistent. If you or somebody else print it on a Prusa (MK4, MK3S, MK2.5S or Mini) it is worth a trial. On my XL the tension works most reliable below the middle between min and max. In order to get the right stiffness it has to be printed from PETG as described.
RE:
The diagonal shift in the middle of the bed shows that one stepper missed steps. The shift in x only is probably the same stepper only but at the front the y-axis is already at its end. While off rotate one stepper by hand and you see which belt is off. You will have to adjust the other belt as well in order to keep the gantry orthogonal so that it contacts the stops on both sides when referencing.