Hi everyone,
I finished bouilding my 3D printer last week and I noticed that I have some scale problems on the objects I print.
For example, I tried to print this part which is supposed to be 50mm * 50 mm (thingiverse.com/thing:53668/#instructions).
I measured it and I got: On x axis :50.9mm and on y axis it’s even worse with 53.9 mm.
Could someone help me?
Thanks!
Did you set the correct steps/mm for X and Y axis?
Check with firmware eeprom settings in repetier.
Thanks for your answer ichbinsnur.
What settings should I have? ^^
Do NOT mess with the stepper settings to correct part sizes!
50.9mm is pretty close taking into account variations in extrusion widths, 53.9 is out quite a bit and sounds like you may have an out of spec toothed pulley.
Send M503 to get all the configuration settings, like steps per mm.
Check that the axes are actually moving by the requested amount.
Send ‘G1 X100’ (move X axis 100mm) and measure the actual distance moved.
Repeat for the Y axis.
There are various online ‘reprap’ calculators that will give you the steps per mm for your belt pitch, pulley tooth count and stepper setup.
Thankts Paul for your answer,
The parameters I have un thé firmware are the une in the last Marlin version so I guess they are OK.
Ans when I send G1 X100 to the printer or moves from about 103mm in x and 106 mm in y…
For the stock 10 teeth T5 Pulleys you should have 64 steps/mm.
AFAIK the original Velleman settings are 63.6 or something.
Did you just build the printer?
If so, it might be that the pulleys are off in diameter.
Do they run smooth and concentric or do they wobble around?
I agree, it sounds like the pulley pitch circle diameters are off.
Thanks for your advices. I ordered new pulleys and I will try them. For the moment I cheated and modified the firmware to get something quite correct (0.5 mm on a 50mm piece).
I will keep you informed when I have my new pulleys;
Thanks
If you got it correct like 0.5mm that’s fantastic.
Why then change the pulleys?
Never touch a running system ? 
Hey there,
excuse me for jumping in, but where exactly did you fix this ? In the source Code and recompile ? Or in the Software ?
cheers,
Jens