Depth of cut increases

When carving a sign with a 90 degree v bit the depth of cut slowly increases as the job progresses. Irrespective of what part of the material this may be. On returning to is home position, the bit has lost approx 3mm in height. Any ideas, i am using Sainsmart prover 4030 cnc.
Regards Mark

1 Like

My thought would be you are pushing the machine to hard and it is loosing steps.

1 Like

Your z height isn’t changing, but the top of your board is not parallel to the spindle.

For vbits you workpiece really needs a top parallel to the spindle plane…
You want to start with a surfaced wasteboard and a planed board, but often times this is not perfect enough for v bits and the wider the angle, the more precise the top needs to be…

The best method is to surface the piece using the cnc…

Another good method I’ve used when surfacing isn’t practical is shimming as shown here:

The OP mentioned that upon returning to the Home position the bit lost some height, so I think either @WayneHall might be correct or there is a pulley or coupling loose on the Z-Axis. If it were just the board being warped or not truly parallel to the machine travel, the Z-Axis should be at the same height that it started the carve when it returns to the Work home after the carve.

No doubt that the wood is bowed if it is from a big box store though… :slight_smile: :joy:


Brandon Parker


This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.