Circular accuracy when printing

[nannyogg82]

So after many many weeks tuning, I think I have finally got my Voron working as it should apart from one thing. Whenever I print anything circular it comes out slightly pinched and oval shaped. I've tried the belts at all different tensions, from so loose they slip, to so tight they cause a layer shift, and across the full range of tensions the same thing still happens. Looking back at all my test prints this has been happening since day one, but has only been noticeable recently as I have been using a white filament. When printing calibration prints I have noticed that all these errors seem to occur on the X axis, that's where the pinching of the circles shows up, or on an XYZ cube this is the shorter side by up to .4mm. Does this mean the X axis needs tightening up independently of the Y?

I've looked everywhere I can think online and can find very little in relation to this issue, especially for Voron machines. Any help will be greatly appreciated.

[smirk]

One question, is it consistently skewed/pinched? In other words print the same circle more then once are they all the same or randomly variable? Just trying to guage how bad things are: consistently bad is better than variably bad

Might not be belt tension might be squareness of the gantry/overall frame. Not having a 2.4 (built) I'm probably not best qualified to advise. I presume you've watched Nero 3D's various piece on gantry deracking and squaring. @Buurman or @mvdveer wiith many 2.4 builds under their belts between then will have greater insight than I.

 

 

[nannyogg82]

So this is probably the best illustration, the light shield for the BTT screen that came in my parts kit that I never used. When compared my white one is slightly pinched at the bottom left and top right of the print, similarly with the skirt. I thought I had sorted the racking issue a while back. Do you think that's likely what it is?

[smirk]

If it's very consistently wrong then it most likely mechanical, i.e. frame/gantry not perfectly square,  and it's probably not out by a huge amount going by the subtleness of the difference.

[claudermilk]

I agree. Something is probably out of square in the printer. I'd watch Nero's video that @smirk linked and make sure the printer is square and gantry is de-racked.

It also looks like you have some layer adhesion issues with that white part, but one problem at a time.