June 12, 2019 at 1:38 pm #103227
I have finished my MPCNC everything is square and correctly mount (I think). I first had some issues with the steppers that were just rattling but not moving. It happened to be a wiring issue, that I fixed after some research thanks to this video : https://www.youtube.com/watch?v=bR3853iNaW8
Now everyhting moves but the steppers still doing that rattling noise but as soon as I remove the belt it’s fine. It’s like they are not powerful enough to move everything. I tried the crown test anyway but the drawing is really bad and not precise at all (almost square instead of round).
I am using Nema 17 1.5A 2.4V 1.8°420mN.m with A4988 drivers on a Mega 2560 and a Ramps 1.4 but do you think it’s enough or should I switch to DV8825 and more powerful steppers?
Also, to run the crown test, first I place the gantry on the corner and then I set the Z with a sheet of paper. I hit start, the tool goes up move to go in place and then go down, but way to down so the pen is pushed up.
Do I miss something? I believe it’s a tool setting in ESTLCAM but I don’t really understand all the settings of the tool. Can somebody help me about it?
Thank you for your help.
June 12, 2019 at 2:21 pm #103231
- This topic was modified 5 days, 9 hours ago by Alex.
Did you set the pots on your drivers to match your steppers?June 14, 2019 at 3:02 am #103350
Thank you for your reply, I forgot to write that but yeah I did. I set 0.7 and I tried a bit lower but nothing better.
And I don’t really know how to calculate the current tbh. I found some things that explains how to do it but I did not really understood it.
I have read the page and the text about the stepper driver current here many times : https://www.v1engineering.com/assembly/ramps-wiring/ but I still don’t understand ^^’June 14, 2019 at 8:18 am #103368
0.7V is for DRV8825, the setting and equations are different for A49’s.June 15, 2019 at 5:52 am #103450
Yes that’s what I thought, but I still don’t understand how to calculate it and I don’t find anything clear enough for me.
Guess I will continue my research. Thank you anyway for your replies.June 15, 2019 at 9:33 am #103470
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