Fret Cutting

[Cartierusm]

Hey, what's the easiest way to cut frets to match the fingerboard radius. I have artcam and Rhino, but I'm not very adept at Rhino yet and I can't figure out how to draw 3D in artcam. All I guess I would need would be one 12" radius Line going up and down the Z axis .090" high and then I could cut and paste and place them in the correct fret positions. Any suggestions. Thanks.

[jabguit]

Are you talking fret slots?

[ger21]

G18 or G19 arcs.

[turmite]

Originally Posted by ger21 G18 or G19 arcs.

Or G1 moves in an interpolated curve!

What help with Rhino do you need to get this going? That might be a better way to go at this?

Mike

[RandK]

Model exactly the fretboard surface that you want. Cylindrical ? Conical ? Project the lines indicating the fret positions onto the curved fretboard surface. Move those curved lines down to indicate where you want the bottom of your slots. I'm assuming your cutter diameter will match your fret slot width. Use a 3d cut path in CAM.

[Cartierusm]

HAAA...Honestly I really appreciate all the help, but I don't know how to do any of things all of you describe....HEE HEE. For those of us with cro-magnum brows how about dummin' it down. Thanks.

I'll check out what the G commands you descibe as far as Rhino I come from a graphic design background and CAD confuses the hell outta me. For instance I was able to import the arc (12" radius) line from Adobe Illustrator into Rhino but when I went to rotate it from flat to standing up so it looks like I want it asks for points of reference. To me I want to be able to exactly, with numbers, rotate it. Why can't I just say this piece here roate about the Z axis 90 degrees. Anyway, these are the hurdles I'm facing when trying to learn CAD. I'm used to using a window with number to draw specific lines and number to specifically place objects exactly where I want them.

[fatal-exception]

Fret slots don't need to follow the radius of the fingerboard. As long as they are the correct depth on the ends of the frets, having the middle deeper dosen't matter, unless you are just looking for additional work that might jeopardize the accuracy of your slots....


Paul

[BobF]

I don't think most fingerboards are radiused (2 piece finger board) on the bottom, and unless cut with a CNC very few have radiused slots. Its far more important to get the scale right.

[RandK]

Fret slots are normally radiused when cut with a CNC because the expensive cutters are tiny .023-.025 and the cutting length is only .070 for the Micro100 bits and .090 for the Precisebits (IMO a much better bit). There isn't enough CL to go straight across, especially on a Fender radius. Radius the board then cut the slots of course.

Cartierusm: I don't have time for a picture show right now but here's a small model with a few sparse notes. The Rhino level 1 and 2 tutorials on the disc are very good try them. Like I said before, make a simple surface. Make a set of lines representing the slots from something like fcalc and then project the lines onto the surface and move those lines down to your depth. Yea, in a cylindrial FB the slots match the same radius but if you go compound or build in some relief you'll need to project them. You'll have the surface to machine the radius and the 3d profiles for the slot.

[Cartierusm]

Thanks guys.

[NB70]

I have written a ruby script for conical tapered fingerboards (with curved fret-slots) for Google's free 3D design program Sketchup. I haven't tested it on a CNC machine yet. You can alter most of the parameters to your needs.

To use the plugin you should download it to your Sketchup plugins folder. If you have installed Sketchup on the C: drive then this folder will be at C:\program files\google\google sketchup 6\plugins. After copying this file you should now a menu options in the Sketchup Draw menu to draw a fingerboard. I had to alter the file extension from *.RB (Ruby) to *.TXT (Text) to allow me to attach it here. You should change it back to *.RB if you download it.

The script's webpage is here. I am hoping to update it soon to make it more useful. At the moment it produces a 3D mesh of the fingerboard, I think single lines defining the fret slot cuts would be more useful for CAM.



This is off topic but I have been pondering about this. The design of the guitar fret, with it's barbed tang, is a consequence of sawn fret slots which have been used for centuries. Since we now have CNC machines that can mill fret slots why not just use a ball nosed end mill to mill a round bottomed fret slot and use conventional round wire with a matching radius (glued in) for frets.

[dbassva]

fret tops are not perfect cylinders for one thing....and you would still need something for them to grab onto to keep them in place when the wood moves....there is one company that actually has a pattent on something similar....they are something similar to diamond shape like a 5 sided gem shape if you know what i mean....im sketchy on the details, its been awhile since i looked at them...but i do remember they claimed they did it by hand with a router and a jig....