printing problems with my MPCNC

Hi all, I attached a picture of the problem I’m having to print , the corners go wrong !! I think the squaring is well, attached a picture of this too . I tested with all possible configurations , printing fast , slow, with different layer heights , etc. My MPCNC is really great with a volume of 1000x500x330 mm impression and I’m using a nozle of 1 mm.

Thank you very much!!

How fast are you printing? Your machine is extremely tall on the z axis you need to print slow at that length, the accelerations will cause wobbles everywhere. You might want to double check your z axis threaded rod to see if it is bent as well.

Im printing to 2200 mm/min and 200mm/s3, is not the threaded rod , I just verify. :frowning:

Do you need it to have that much z length?

So that is about 36mm/s, Try half that and see if your prints improve drastically. At that speed you are whipping the head around and it is probably causing your issues. Or you could raise up your work surface.

Are you using my firmware or your own, I ask because of the acceleration settings?

Just as a reference point on all my dedicated 3d printers, prusa style, non-bowden. I print ant 30mm/s with minimal acceleration wobbles/artifacts on my prints. Looks like your print head is hanging about 12 inches out. For every half the distance your z is hanging your machine will be 2 times as rigid, every mm counts.

I understand , I’m using your firmware , with an acceleration of 200 , I tried it with the speed that suggested to me and improved considerably.
What would be the right height for printing at a speed of 35-40 mm / s ?
thanks for your help!

Thats just it, I never print that fast, even on a dedicated machine. Do you have a need for such a big z axis? I have 8 printers and have been at this for many years and even at a design job always needing prototypes I never printed anything taller that 6".

If you accelerate too fast you will get ringing, to slow and you will get soft corners. The acceleration I had set in the firmware (200) was the slowest I could go before getting bad prints at 25-30mm/s.

If you want faster print times, on such a giant print volume look into larger nozzles.

Yes, that certainly a nozzle issue, just did have the same problem and that started from using the smallest nozzle, so tried replacing to a larger one since I have spares, and you can even see what causing that because of the outcome of the prints that seems not so fit to what is desired.

Jean of