skewed print

Hi all,

I just bought my first diy 3d printer, a 3d stuffmaker mega prusa gen 3. Took me a bit to build it(being a dad and having a full time job) but I finally managed to put it all together. I calibrated it according to the manual that came with the kit. Love the size of things I can print, but my issue is that my first print is skewed toward the positive y axis. Attachment 7057

this came from a file made by 3d stuffmaker.

any thoughts? also I'm a total newbie at this so bear with me please if this subject has already been covered somewhere else.

thanks :)

Some initial questions:

Do you have any binding or friction on the Y-Axis? Can you confirm that the printer moves along the y-axis freely (in both directions) when not printing anything?

If a printer can not "retract" to it's original start location because of some bind/friction it will exhibit this behavior.

Quote:

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Originally Posted by LuckyImperial

Some initial questions:

Do you have any binding or friction on the Y-Axis? Can you confirm that the printer moves along the y-axis freely (in both directions) when not printing anything?

If a printer can not "retract" to it's original start location because of some bind/friction it will exhibit this behavior.

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yes it does move freely, the belt is tight(as much as I could tight it ) and it does not skip a tooth when it moves.

The belt is not required to be extremely tight. As a matter of fact, it just needs to be taught. A belt that is too tight will increase the amount of torque required for the motors to move the head.

Skipping teeth would likely not be an issue (especially if the belt is set to the correct tension). It comes down to the fact that the motors can't spin because they can not output enough torque. A belt that is too tight may exhibit this behavior.

Is there any information you can reference for the belt tension of your specific printer?

the belt is not overly tightened, I just made sure that it wouldn't skip while the motor is turning and unfortunately there was no required belt tension provided with the manual.

Just to be sure I understand correctly...

Even though you tightened it "as much as I could tight it", it is not overly tight? Is the tensioner bottomed out?

yes you understand correctly and there's no tensioner with that printer, just 2 bearings, the motor and the 2 belt attachment points on the base plate.

Interesting.

What speeds are you trying to print at?

it's set a 300 mm/min right now, could it be too high?

Most people communicate using mm/s. 300mm/min converts to 5mm/s and is actually very slow. How long did it take to complete the gear above?

Typically most printers operate anywhere from 40-60mm/s.

Also check your non-printing speeds. Since all your shift is in one direction, it could be skipping at the start or stop of a rapid non-printing move.

Quote:

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Originally Posted by LuckyImperial

Most people communicate using mm/s. 300mm/min converts to 5mm/s and is actually very slow. How long did it take to complete the gear above?

Typically most printers operate anywhere from 40-60mm/s.

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I pause it before it was done, but it was suppose to take like 5 hours to complete. I did raise the speed up for another test print. It was better but not perfect, looks like it shifted just for a few layers and then corrected itself.

Quote:

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Originally Posted by Davo

Also check your non-printing speeds. Since all your shift is in one direction, it could be skipping at the start or stop of a rapid non-printing move.

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if that's the case, how would you fix that?

Lower the velocity of non-printing (G0) moves.