Ender 3 Y axis problem

Hello, i wonder if someone can advise on the issue. I have just assembled Creality Ender 3 printer and printed a 20 mm calibration cube. It actually printed well, however when i measure the dimensions - y axis side of it appears to be 19mm instead of 20. X is perfect and Z is 19.7mm (which is fine i assume). I would imagine that steps per mm are already calibrated properly at the factory. I wonder if it could be that y carriage is a bit tight, could that cause this size distortion?

If one axis is tight and binding, you often see shifted layers. (search 'skipped steps' too )
When the walls of the cube are vertical, but too small you can recalibrate the axis. Put the new found steps/mm in the startcode of your slicer ( M92 Y####) or overwrite the eeprom. (Send M92 Y#### and M500 directly from Pronterface or other terminal)

I've just got an ender 3 and whilst assembling it I noticed that the belt rises a bit between the line of the pulleys, so as such I suspect there may be some very slight distortion of prints along the Y axis depending on how far the print is from the highpoints of where the belts attach, I think adding a small idler and elongating the holes for adjustment may solve the issue if there is room to do so the other issue I have is the pulleys are a press fit on mine so fitting dampers is going to be fun

Quote
o_lampe
If one axis is tight and binding, you often see shifted layers. (search 'skipped steps' too )
When the walls of the cube are vertical, but too small you can recalibrate the axis. Put the new found steps/mm in the startcode of your slicer ( M92 Y####) or overwrite the eeprom. (Send M92 Y#### and M500 directly from Pronterface or other terminal)

Thank you. This is very useful, i didn't know it could be set in G-code. I suppose it is better to thank someone 1.5 years down the line than not at all ) I wanted to run some more tests before replying, and i just unpacked and started playing with my printer again (1.5 years after original post). Sometimes it takes me ages to follow through with something.

Edited 1 time(s). Last edit at 02/02/2020 02:49AM by AlexPl.

Quote
pliers
I've just got an ender 3 and whilst assembling it I noticed that the belt rises a bit between the line of the pulleys, so as such I suspect there may be some very slight distortion of prints along the Y axis depending on how far the print is from the highpoints of where the belts attach, I think adding a small idler and elongating the holes for adjustment may solve the issue if there is room to do so the other issue I have is the pulleys are a press fit on mine so fitting dampers is going to be fun

Thanks a lot, i can see the issue. I have tried printing calibration cube at the centre and at the start of the bed, there seems to be a small difference in Y. It looks like that this "trapesoid" type setup is influencing the Y, i would have never noticed this. If i get to trying to fix this potential problem - i'll post the update here (in another year or 2 when Ender 3's will be obsolete and we will all be wearing silver jump suits )

Edited 1 time(s). Last edit at 02/02/2020 02:50AM by AlexPl.