cut a truss rod slot with almost no measuring

[John Cross]

I was experimenting with a technique that I saw in a woodworking magazine a while back for cutting the truss rod slot on a neck blank. The only measuring you need to do is to set the blade height for your truss rod and get it centered on the neck which I just eyeballed since the blanks I’m using are oversized.

The first thing to do is to make a shim that is the same thickness as the kerf your sawblade cuts. I’m using a Diablo blade which is 1/16. I happened to have some 1/16 phenolic which worked perfectly. I also made an auxiliary fence out of ¾ plywood that clamps onto my regular table saw fence.

[John Cross]

The first cut gets made with the shim behind the auxiliary fence.

Next, I take out the shim and use two truss rods (same model I’m using) as spacers between the regular fence and the auxiliary fence. I placed them in line with the clamps so I wouldn’t get any weird twisting or anything. Make sure you run the blank through the saw with the same edge against the fence.

[John Cross]

All I need to do then is break out the thin web between the two slots and clean up the bottom with my homemade plow plane. Perfect fit first try.

[Bob Gramann]

Cool idea!

[David King]

So the truss rod spacers are not side-by-side but one at the bottom and one at the top?

[John Cross]

David

The truss rods are placed directly in line with the clamps I used to hold the plywood auxilary fence to the table saw fence. They are sticking straight up (you can see them in the second picture down - the blue rods right by the blue fence clamps). I could have put them in horizonatlly but it was easier to put them in behind the fence if vertical plus I the rod adjustment nut is a bit wider than the rod so going horizontal would have messed up the spacing.