Okay…slow down the hoards of better minds. <snerf, snerf>
I am cutting 6 of these panels in 0.125" Luan. The areas contained in the RED box needs to be cut at a 75° per side, while the areas contained in BLUE need a 90° cut. My thought was to cut everything at a 90° cut, then somehow delete the areas in BLUE and re-cut the areas in RED with a 30° V-bit with no offset which would give me a 15° angle.
duplicate / break open, then close and offset the geometry which needs the V cut so that that can be cut w/ a V bit (and preview properly) — tool engagement should be low enough that the connected part at the straight edge will hold things in place okay
a straight cut / follow path should address the base cut.
Thanks @WillAdams. I appreciate that. I am attempting to build a mini “Airstream” trailer for bicycle, using composite construction, and this is the domed front.
P.S. HERE is a link to how the dome was laid out. I had to do a bit of fiddling to create a half hemisphere, but it was remarkably easy.
Instead, open the .dxf in LibreCAD, export as MakerCAM SVG, open in Inkscape, re-save as PDF (I’ll think better if I use Freehand — once we’ve got the numbers for this worked out we’ll re-do it in Carbide Create).
Exactly. The line segments let you set up If you use the link that I provided, you can get a perfect .pdf. the line segments (rings) are used when using glue tabs.
I used 32" diameter, 10 “rings” and 12 segments (since I need 6 to make a half-hemisphere) 0 glue and 0 margin.
We’ll just use 1.7mm (the 0.0015mm can go towards the glue line) and we need to offset by half the dimension — I prefer to do this twice, once w/ the full dimension, the second time with the halved:
You could use math, and would prolly come up with a more precise answer. I was thinking about this approach though, which is the kind of thing I sometimes do (probably out of mental laziness, in part) but it occurred to me for the first time just now that what you get with this graphical approach is a built in visual check on the reasonableness of the calculation that you don’t with a strictly mathematical approach. Here’s to thinking with the right side of the brain!
Also @WillAdams are there any “gotcha’s” if I lie to CC and tell it that I am using a ball nose bit, but slip in a V-bit to do “no offset” cutting? and get my 15° bevel per side?
I would worry about the toolpath calculation, and getting the positioning accurate — doing it as a V carve allows one to get a preview, which I prefer.
So, for the V carve, take the center path and expand it by the desired diameter w/ rounded ends: