Looks like the problem was addressed here but I don’t really understand what the answer is:
@WillAdams the tool duplicates you mention in this thread…are you saying to modify the tool diameter so it’s smaller and allows to be closer? What do I lower it to so I ensure the tool won’t touch the contour line? I’m using a .25mm ball mill for a 10.5 degree V-bit so it’s slightly more blunt than an actual V-bit, and want to make sure I don’t make the inlay cavity larger than I intend. The end goal is to trace the interior line so my face-grain inlay is crisper and reduces tearout when I do the V-carve toolpaths.
The problem with modifying the tool diameter is that one then needs to also adjust the Depth of Cut and the preview will not be accurate.
It is far better to leave the tool as-is and to add offset geometry as necessary and set the Depth of Cut to what is desired to achieve a given result — that will result in a correct preview.
Ok, so how do I do this? I have it set for inside/left and 1mm deep, but it’s still acting like the entire .25" bit is tracing the inside. How do I get it to just cut the first 1mm of the normal v-bit path if I were doing a full V-carve?
You have the bit diameter set to 0.25" for diameter and on a contour cut this is what the software is looking at for an inside/left cut of the line. What is the width of the tip 1mm up from the bottom/tip? It’s probably between 1/16" to 1/8"? If you set the diameter in the geometry filed to the actual diameter the bit will be at 1mm in depth you may get the cut you’re looking for. You also could use 0.05 in the “Stock to leave” box and it will leave that amount away from the contour cut. You can try this on a practice piece of wood first and dial it in. CC does not support ball nose bits as of yet so there is a learning curve with them.
To get the line to move I have to put in a negative value in the “stock to leave” with a left/inside offset so it will get closer to the line I want. -.125 puts it on the line, but I’m not sure how much to back it off. It’s a very narrow bit and my calipers are showing 5/129 at around 1mm depth…so adding .0375 to that number… -.0875?
It’s crazy that it’s this complex to just trick the machine to trace the inside of a line. Do other software handle these bits/tasks easier?
You don’t need to add a negative sign for the value in the stock to leave. It knows which side you’re cutting on based on your selection of inside/left or outside/right. It just needs a value and it will pull the bit off the contour line to leave the amount of material you want to leave.
No different than a pocket cut where normally you offset the roughing (or hogging) cut to get ride of majority of material. Most use a value of 0.1” to 0.15”, then the “finish” or final pass will remove the final amount of material.
My apologies as I locked in on the 0.25” diameter bit and the tool path you showed and pocketing took over my thought process as I was working a file at the time. Tod1d is correct, it’s best to measure the tool by drawing or doing the math to get to the specific radius at the depth you intend to cut.
so -0.125 to make up for half the .25" bit, and then add the radius of the smaller bit (.092 mm / .0036 in). so -0.1214? It looks on the line still. I guess I just have to trust the math?
Even with the math worked out you need to actually test cut to see if you’re getting the results you want. Most use mdf or plywood for test cuts and then once dialed in will cut the file in the desired wood. I have found that once my process is dialed in in tests cuts as mentioned that I have had slightly different results when I cut in the desired wood due to the actual material itself due to hardness and/or specific grain patterns.
So if you have a small off cut or enough of the desired wood I would try a test cut in that as well before the final run for your project.
yeah for this one it would be hard to test, as I’m trying to cut over an inlay. A bit convoluted but I adjusted the lines to be smoother, and made them slightly larger, and going to cut it on top of the failed inlay in order to get better (no) lines. At this point it would probably be easier to just do another one, but I’ve taken it up as a challenge at this point.
