Rough vs finish pass... need help

OK, so I’m using V-carve Desktop, and I’m trying to cut something that has some fairly tight corners. I figured I’d try doing my roughing with an 1/8" bit, and a full-depth finishing pass with a 1/16" bit. Now, there’s a feature in V-carve for a “separate last pass” but I’ve read that I shouldn’t use that. Instead I should generate a toolpath for my 1/8" bit and use a small offset, then generate a separate toolpath for my 16" bit with no offset. Unfortunately, every time I try a finishing path, the bit chatters, then takes a detour across my work. I may have to forgo the finishing pass altogether, but I’d like to try to understand where I might be going wrong. If anybody has some input, that would be great. Should I go faster/slower on my finishing pass? What’s the most I should be taking off with a finishing pass? Should I reverse direction? Hoping to learn from some of the wealth of experience out there on this board.

If it is a profile cut, using your method, you would still have to make several shallow passes with a 1/16" bit assuming your material is wood and is thicker than .0625".

If it is a pocket, or you convert your profile to a pocket, then you can use advanced tool options and select the option to use a roughing bit. But you would still have to make several finishing passes.

If it is profile, it is probably more efficient to cut the piece out using your finishing bit and multiple passes.

It is a profile cut, in wood, 1/4" thick. So it sounds like I should forgo the finishing pass. I’ll give it a shot doing the profile with the smaller bit and see how it goes. I’ll see about slowing it down some to cut down on chatter as well. Thanks to both of you for your input…

I had to repeatedly cutout a Maryland Blue Crab (long story), that required a 1/16" bit so I just looked up my settings. It cut well at .05" depth of cut and 30 inches per minute. If that helps. But my machine is pretty rigid and I am using a router not a spindle. It was 11 passes through my .5" materials.

@Earwigger, I’m in Maryland, so I know the blue crab obsession all too well! I have the Dewalt, but I haven’t stiffened yet. I have parts to do the X, and just this week Amazon lost my box containing parts to do the Y. Soon. I know the Vcarve software is aggressive, and my settings are below the software settings in most cases. I was definitely pushing the 1/16 too hard thou, based on your settings. I will back that down.

@RobertCanning, I definitely think an x-carve specific database of feeds/speeds/DOCs would be good. Nothing beats first hand experience.

Cool - here is the wall hanging people from Maryland keep ordering. It is made from recycled shingles and pallet wood, but the crab is MDF, primed brown, then painted white and distressed. I did sell one to someone in North Carolina but she was probably a r

elo from Maryland :slight_smile:

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