Hi All!

 I'm new to the forum and new to CNC. We've got our machine up and running. Use Vcarve Pro to design and Mach3 to run the machine. Profiles seem to be cutting great, but when I need to cut something out inside of a piece (a small window for example), the router seems to plunge down just outside/inside of the path line, leaving a small indentation where it's plunging. I'm not sure if this is a Mach3 thing or a VCarve thing. I've searched all over, with no luck (though very possible I'm not searching for the right thing). Any help anyone can offer would be great!! Thanks so much!!

Could be in the code but if I am understanding what you are meaning it could also be the machine flexing during the plunge.
Hood

Can you see it in the V-Carve preview?

I don't believe it shows on the VCarve Preview. As far as the machine flexing, if that's the case, it's doing the exact same thing on every identical part. (I have 5 of the same parts all being cut out of 1 sheet of MDF. The "notch" is the same size on all of them, and right where it plunges, no matter the orientation of the part on the MDF (if that makes sense). Thanks for the replies so far!!

Can you post a picture?

Yes, I will in the morning when I get to the shop. Thank you!

When creating the toolpath for your cutouts a 'lead-in' / 'lead-out' may help resolve your problem.

Tweakie.

As far as the machine flexing, if that's the case, it's doing the exact same thing on every identical part. (I have 5 of the same parts all being cut out of 1 sheet of MDF. The "notch" is the same size on all of them, and right where it plunges, no matter the orientation of the part on the MDF (if that makes sense). Thanks for the replies so far!!

That would be expected. Machine flexing doesnt have to mean the actual frame or gantry of the machine it can be backlash, the spindle or its bearings. Plunge moves put the most stress on a cutter as it has a flat bottom and tries to wander. If you dont believe me it out by putting a cutter in a hand drill and try to drill a hole through some wood
Lead ins like Tweakie mentioned may help, doing a ramp into the material instead of a plunge likewise or if you have to plunge then do a finish pass.
Hood

Ok great! Can you further explain what I would do to make a lead in vs. plunge? Thank you!!

Hold that thought. I think I'm understanding. Gonna run a sheet now and see what happens.