Prusa logo first print - advice to improve print?
Hello folks,
I just finished assembling a Prusa I3 MK3s and ran the initial calibration. I ended doing the z-level calibration several times until I got a square pattern that I thought it was good (currently doing -1.700). Everything seems to b calibrated correctly, but when I tried to print the prusa log from the SD card I end up with the following print which I don't think it correct.
Could you please guide on what areas should I focus on to improve the print calibration?
Hugo
RE: Prusa logo first print - advice to improve print?
Something is very loose; tighten the belts and the belt drive gears.
And the gears need a special sequence:
Flat First: Drive gears must be tightened flat-first.
1) Start with both set screws fully loosened so the pulley is free to spin on the motor shaft.
2) Align one set screw dead center with the flat on the motor shaft, slowly tighten the screw until it fully contacts the flat surface.
3) Torque the flat set screw to spec.
4) Now tighten the jam set screw, and torque it to spec.
Once tightened, never touch the flat set screw unless the jam screw is first fully loosened.
Why Flat First? Set screws have flat ends. If you tighten the jam screw first the set screw on the shaft flat doesn't fully contact the shaft, only one small edge of the screw surface is biting. Reversing torques can easily shift the shaft to a position the flat screw no longer contacts the shaft. This lets the jam screw wriggle loose. And after a while, vibration loosens the screws until the gear is free to rotate.
RE: Prusa logo first print - advice to improve print?
Thanks for the advice! I checked and behold, the drive gear on the Y-axis was loose (don't know how, either forgot to tighten it or it got loose somehow). Adjusted it, and things got better, later on adjusted the y-axis belt (it was not tight at all) and the quality got way better.
It's probably still not perfect, but very close - most likely I'll need to go over every little screw to make sure everything is tight, but so far, we're very happy with it. Thanks again!
Hugo
RE: Prusa logo first print - advice to improve print?
The gears must be installed a specific way or they will loosen up. Prusa doesn't include the right procedure:
Flat First: Drive gears must be tightened flat-first.
1) Start with both set screws fully loosened so the pulley is free to spin on the motor shaft.
2) Align one set screw dead center with the flat on the motor shaft, slowly tighten the screw until it fully contacts the flat surface.
3) Torque the flat set screw to spec.
4) Now tighten the jam set screw, and torque it to spec.
Once tightened, never touch the flat set screw unless the jam screw is first fully loosened.
Why Flat First? Set screws have flat ends. If you tighten the jam screw first the set screw on the shaft flat doesn't fully contact the shaft, only one small edge of the screw surface is biting. Reversing torques can easily shift the shaft to a position the flat screw no longer contacts the shaft. This lets the jam screw wriggle loose. And after a while, vibration loosens the screws until the gear is free to rotate.