Uneven Offset path

I have been carving hearts for Christmas. I use offset paths to create the lips and cutout. When they cut the lip is thicker at the bottom and thinner at the top. The pieces fit together perfectly, but the lip is not uniform. What is going on here?

1 Like

Hi @JimmyHale56,

Can you share the design project file and generated G-code file(s) for a quick check, as well as a picture of the piece (and possibly the stock you started from) ?

The two main reasons that come to mind would be:

  • zeroes shifted between successive operations, if you are using multiple G-code files and run then sequentially with some re-zeroing involved.
  • the stock dimensions not quite matching what you entered in the CAM and zeroing off a corner.

It could be a mechanically issue too (pulley slipping) but this seems unlikely if you cut two pieces and the have the exact same offset and fit perfectly.

1 Like

2 Likes

Heart Box Summer.c2d (528.5 KB) Heart Box Summer.nc (906.7 KB)

2 Likes

It looks like the pocketing (which happens before the cutout) caused either the stock to move, or the machine to slip.

2 Likes

Agree with Gerry, the G-code is fine,

so it must have been something slipping along the Y axis just before/during the cutout.

Are you cutting this on a SO3 or XL maybe ? Your stock defined in CC is 14" tall and oriented vertically:

Depending on where your stock was attached on the wasteboard, it is possible that the top part of that “summer” heart was slightly beyond the reachable work area, just barely enough that even though the pocketing was not a problem, when going to do the cutout the cutter moved too far back along Y and the Y plates contacted the bottom of the machine. If this happens, there would be an ugly sound (easily overlooked under the sound of the router), the stepper motors would lose steps, and then the cut would proceed…permanently shifted for the rest of the cut, which would result in what you are seeing.

1 Like

Work piece was in center of machine, taped and clamped. Seems like if it had moved the fit would not have been as perfect as it was. I am running one now with tape, clamps and brad nails.

double sided tape an clamps, center of machine.

the worry is that on an SO3/3XL you would hit the maximum of Y, and then the machine loses steps… which is consistent with what you see… if you have a 3XXL you have obviously more space in the Y direction

What you can do to verify you are not running out of travel on Y, is run the cutout toolpath only, as an air job. If there is any collision, you will hear it distinctly.

I agree it’s unlikely that the stock moved, but running out of Y travel…well it happened to me a couple of times.

The two halves would still match perfectly it the problem happened (as I think it did) during the cutout. By then the pocket and lip are already done, and this is before the problem happens, so there is no reason why they would not match.

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.