Official Luthiers Forum!

The recent discussion about fret saw blades inspired me to test the idea of using a 1/2 moon blade on an oscillating tool to cut fret slots. I did a few test cuts in some coco bola and it seemed to work O.K.. I cut the slots by hand using a piece of wood clamped across the work piece to guide the cut. The blade I used cut a kerf that fit Stew Mac wire perfectly. The next thing I plan to try is making a small "table saw" with the oscillating tool mounted as the power source. I think that will make things go a little faster, give a more uniform depth of cut, and add some accuracy and precision.
It may not be the "hot setup" that a professional shop would require, but could be a low cost alternative for the hobbyist, especially when you consider all the other uses you can use the tool for. What I used was the HF tool on sale for $17 and a $7 blade. They do make one that has variable speed and costs a bit more but still is pretty cheap.

I did that exact thing -- and with the HF blades as well -- mine did not work. I might have some pictures of my failed attempt. This was something I planned on marketing if it had worked out.

The idea is to have a sled like our real set-up, you can see the double miter slots. I gave the tool to my daughter so you can only see where it was mounted. The blade was supported with the two Teflon covered guides. It did cut slots -- but in my view (as an Industrial Engineer) more tedious than a simple hand powered fret saw. Again just showing what did not work too good -- hopefully you will have better luck.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

Hi Ken,
Your design looks interesting. I assume you used bondo or some sort of epoxy putty to make the mount for the tool? I was also considering doing that. Wire ties were used to secure it? (should work) Why the large opening in the table?
I am thinking about making something a bit cruder. A table with the blade sticking up through, and the height of the blade adjusted by raising the front of the table. A simple crosscut fence with guide rails that bear against the edge of the table with a fiducial mark that aligns a mark on the fretboard with the saw blade. I built something similar using a direct drive tablesaw motor and a Makita 3 3/8 inch saw blade.
What did you find to be the limitations of your design? What made it more tedious that sawing frets by hand?

Yep that's good old Bondo --- Plastic zip ties ---- large open is for ease of maintenance -- The blade is attached to the tool 90 degrees off the end to allow the low profile design ---- This unit is designed to use a fret scale template so the depth can be adjusted on the sled by shimming the template --- cutting the required .115" or so depth in pre-contoured Ebony or even EIR FB blanks went very, very slow and quickly over heated the blade (smoking hot!), which actually did not hold its edges well and dulled very fast.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

Thanks for the information Ken,
I was wondering if the fine teeth would cause a problem with burning. I will try to find a blade with larger teeth and bigger gullets. I have resharpened the blades with a file before, but obviously if you have to do that for every fretboard that wouldn't be fun.
I think I will allow some room in the construction to swap out the oscillating tool for a Makita battery powered saw I have used (handheld) to cut fret slots.