CNC Router V1.0 (For Cutting Multiple Materials)

[routercnc]

If the ballscrews are bent then you will get a periodic tightening as you rotate it, especially at either end of travel.

If the ballscrews / mounts / nuts are all mis-aligned then it will have a constant tightening at either / both ends.

Assuming the ballscrew is fairly straight then looking at the design the ballscrew supports and ballnut bracket are probably not completely in line. It doesn't look like you can adjust in the plane away from the sides of the machine, only up and down.

Try moving the machine to the driven end, loosen the 6 bolts holding the ballnut to the ballnut bracket, and remove the floating end bearing. This should allow the ballnut to sit in an unloaded position.
Nip the bolts back up and move the gantry over to the other end. Gently slide the floating bearing back on - it should sit snug onto the mounting block on the side of the gantry. If it is out, fit a shim. If it is tight you need to machine a bit off the mounting block.


Tramming is related to getting the spindle motor normal to the bed so that the side of the cuts are 90deg to the top surface. You can get close by putting a bar in the spindle and using an engineers square to check the spindle is 90deg to the surface on all sides / angles. You can also get a twin DTI block which gives a much better indication of tram condition. Have a read . . .
http://www.cnccookbook.com/CCMillTramming.html