Some weeks ago I bought an ready to mill MPCNC and started rebuilding anything the seller did, because it was awful. After that I was milling some wood and 1mm aluminium, with good results, except Z measurements. After checking many wholes where not as deep as they should and when milling my vacuum table I recognized, that everytime he was lifting Z the height changed randomly. Sometimes he was 3mm higher than before, sometimes, 2mm deeper. I thought it would be the frame and rechecked - everything was fine. When “levelling” the flute was at the same height in every corner.
Then I increased the driver voltage. At about 1.2V I got great results. After a few days I had to mill aluminium and thats why I´m writing this post: I saw, that the Z axis wasn´t able to handle the Z holding torque and the motor was getting very very hot. I got big step losses and sometimes he liftet the spindle and was stottering.
After having this problem I was thinking about solutions for that problem. I´m a 3d printer builder since some years and had some nema 23 laying around. and want to change the nema 17.
Some in this forum were milling aluminium already with the nema 17 but I cant understand how. I think the nema 23 could be the solution, but are there already finished designs, especially for the Z motor?
Have a nice day!