Print issues: Squares = Rectangles, Circles = Ellipses
Hello, I am having trouble with printing shapes on my prusa i3. maybe someone else has had this problem or knows the exact cause.
The issue: Any uniform or symmetric prints will come out incorrectly. I will create a perfect square in solidworks, send it over to slic3r which shows a perfect square, then it prints out with one side longer than the other. For example, a 3mm x 3mm gcode file will print with measured dimensions of 3mm x 2.5mm. Or I create a hexagon with even side lengths, and it will print with some sides longer than others. Circles will look a little like ellipses as well.
Does anyone know what the issue could be? My belts are tight, the xyz calibration says things are slightly skewed but ok, the belt pulleys on the motor are tight as well (with one against the flat part of the motor shaft). I will be using this machine to create wheels for a car (mechanical engineering term project) so I need my circles to be circular! Any help would be appreciated, thanks!
Greg
Here are some photos of the issues:
This should be a square, but is a rectangle
This hexagon is slanted, some sides are longer than others
Re: Print issues: Squares = Rectangles, Circles = Ellipses
Which axis is wrong X or Y?
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Print issues: Squares = Rectangles, Circles = Ellipses
Thanks for replying peter,
When I make a 3mm x 3mm square, the x axis = 2.5mm and y axis measures 3mm, so x axis is the one that is incorrect.
Re: Print issues: Squares = Rectangles, Circles = Ellipses
OK, so the problem is with the X axis. Check the pulley is properly aligned, the grub screw is tightened on the motor spindle flat and that the belt is tight, but not too tight.
Make sure the extruder housing moves freely left/right with the power turned off. Listen for noisy/demic bearings.
Check the adjusting screws in the right hand X bracket are not too tight - you can use a DMM set to continuity to ensure that the screws just touch the X smooth rods.
Check that the X motor cable is not pinched anywhere and that the connection on the RAMBo is good. Also ensure that all the pins in the connector are firmly homed.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Print issues: Squares = Rectangles, Circles = Ellipses
Check the adjusting screws in the right hand X bracket are not too tight - you can use a DMM set to continuity to ensure that the screws just touch the X smooth rods.
This is genius! Don't know why I didn't think of it!
Re: Print issues: Squares = Rectangles, Circles = Ellipses
Hey guys, thanks so much for the responses!
Turns out he adjusting screws on the x-axis were very loose, and this was the issue. I have tightened them and now the prints are much more symmetrical, with just a very slight difference in lengths.
One question though: When the extruded is close to the printing bed, the threaded rod for th right motor (that the x carriage travels vertically on) should be aligned in the z-axis top right piece (orange part on the top of the printer with two holes, one for the smooth alignment shaft to fit into and another hole for the threaded motor rod to go through). However, when the extruded is close to the printing bed, this threaded rod slightly pushes against the circular hole, but it should be sitting in the middle. This means the rod is at a bit of an angle. Is this an issue?
Thanks again guys!
Greg