Fretboard shaping (ruled surface) jig

[Andy Birko]

So I tried the equidistant offset and with that same .008 stepover, I go from 14.9 minutes to 13.2 (according to the CAM software, real life is a little slower as VisualMill doesn't take into account accels and decels).

If I go up to a .01 stepover, it drops it to just under 11 minutes. I don't think the finish will be as good as the raster but it's certainly worth trying. If nothing else, I'm going to try the .01 stepover. Thing is that the .008 stepover needs just the tiniest hint of sanding to get rid of the machining marks.

[Louie Atienza]

I think you should have no problems sanding off .002" extra! And it's a lot faster to sand that .002" off than to machine it!

Did you also shrink your machining boundary as well? With equdistant offset, you should be able to make it just the tiniest bit larger than the fretboard itself...

Thinking about this now, I wish I had the funds for a 4th axis, it would make this go even faster since i'd be able to use a straight bit for the finish pass as well...

[Andy Birko]

Yes, I shrunk the boundary a little to be just the profile of the fretboard. Up to this point, I've been machining about an 1/8" beyond the edge of the profile - which can add up to quite a bit of distance considering the angles involved - even at 390ipm (I lied about the 400 - guess I was too chicken to bring it up to that speeed!)

I'll definitely try the equidistant offset on a piece of scrap to see how it looks. With my cam software (visualmill) it's got a direction change right in the center of the board and I'm just somewhat skeptical that it's going to look as good as the raster. For the purpose of these fretboards, the less hand work, the better!

p.s. I'm probably going to add a Sherline 4th axis later this year. Because I've got an empty driver on my G540, I should be able to do it for a reasonable price. That and my CAM software already supports a 4th.

[Louie Atienza]

Yes, I shrunk the boundary a little to be just the profile of the fretboard. Up to this point, I've been machining about an 1/8" beyond the edge of the profile - which can add up to quite a bit of distance considering the angles involved - even at 390ipm (I lied about the 400 - guess I was too chicken to bring it up to that speeed!)

I'll definitely try the equidistant offset on a piece of scrap to see how it looks. With my cam software (visualmill) it's got a direction change right in the center of the board and I'm just somewhat skeptical that it's going to look as good as the raster. For the purpose of these fretboards, the less hand work, the better!

p.s. I'm probably going to add a Sherline 4th axis later this year. Because I've got an empty driver on my G540, I should be able to do it for a reasonable price. That and my CAM software already supports a 4th.

My current machine uses a xylotex, and only 24v power supply, so there's two limiting factors for getting my speeds up. I do have a G540 that will be used on my newer machine (building it now.) My CAM also supports "ruled surface" machining, though I have not been able to exploit it as of yet. VisualMill was on my short list of CAM software, but since I had to buy dual purpose (I process plate aluminum for some local guys) I needed high-speed pocketing to keeps my costs in line. But VisualMill is excellent software nonetheless.