Start Position/Size Issues

Okay I’m a bit new to CNC Carving and not sure which Category to put this in.

I imported a SVG file (just a heart shaped outline) Added one of the Pro Fonts, (Had to do individual lettering (due to the style I wanted for positioning), I set the Depth of the Image and to where they needed to be, mostly 0" (I wanted the full outline of lettering.

I chose my material (red oak) I set the thickness 0.50", sizes 11.25" x 11.25", and choose my rough bit 1/8" double flute straight end mill (grey), and detail bit 1/16" down cut 2 flute fishtail (lime green).

I go through all the steps: Confirm Material thickness, Secure Material, Pass Type (Rough), Confirm Rough Bit (Grey) Confirm Detail Bit (Lime Green), Confirm work zero, Set X and Y at 0 position (at bottom left corner) set Z at 0 (bit touching board),

Choose “Use New Position” option. Go through the next 3 steps, Raise bit. Attach dust shoe, Spindle is on… Carve.

As it moves into position for the 1st carve, by eye I can see that it’s in the wrong position,

so I stop the program, and the Motor returns to the home position (Which is the position I began at). I back out of the Carve, reopen it and do it all again (Just in case there was a glitch in the buffer/cache). Go through all the steps above again. same thing, but I wanted to see what it was doing. Around the 3rd pass the machine stops moving and sits there, before I could go to the Computer to stop the program AGAIN, it begins to move, it plunges all the way through the material, backing and around 1/4" into the waste board, tearing a 3 inch groove as it went. I hit the e-stop button before it could damage anything else.


this is not the 1st time it has done this, but, it has been the most disastrous.

Funny thing though I almost always do a test run (Usually with Scrap or MDF to ensure and or Proof the carve).

And here is an mistake on my part (3/4" material, 1/2" bit depth)

So is there anything I am doing wrong here? I’ve carved dozens of projects and this happens maybe once every five or six carves (usually without damaging the waste board).

Why is the carve offset? I’ve tried compensating on the material and shifting it over, redesigning it in easel… Seems the only way to do it is add an extra 3 inches of material to the sides and have ALOT of waste.

Any Suggestions?

Your description doesn’t match the pics in the post. Board size is shown as 10.5" vs 11.25". Detail bit shows 1/32" yet you mention using 1/16". Reason I mention is that the thin outline is probably not carving with the 1/8" because it’s too small. So the pic showing ‘should be here’ is not inaccurate as it’s cutting the rough pass, not the detail.

The last pic shows the smallest heart with some rough carving, but not the detail. It doesn’t look like you’ve carved the detailed bit part at all in any of the pics.

Also, not sure why you’d choose ‘use new position’ either. When carving the same piece for a detail bit, you simply change the bit and re-probe, but you should be using the same position or the same x/y location.

As far as the plunging, that’s a different problem or perhaps it’s related to your choosing use new position as, I think, that will change your z-probe location as well.