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Have both a MM 16 and a Hammer sliding table saw, and was thinking of the most accurate way to cut a 10 degree angle. Was talking to a retired machinist friend, he said he has some type of protractor that might work to mark the angle, but needs to be accurate to cut a scarf joint. How do others cut a scarf joint?
Scarfing a guitar neck I've just marked it with a protractor and then cut it freehand on the bandsaw, followed with a plane to flatten and clean up the surfaces for gluing. To do it more frequently I'd think in terms of a dedicated sled to hold the wood at the correct angle on the table saw. Setting up a shooting board at the desired angle would let you plane it with pretty high precision.
I second Roger's advice.
How thick is the piece. If it's less than 4/4, I'd vote for the table saw. The thicker the piece, the more I think bandsaw+hand plane becomes the easier solution - even for multiples.
Edit I meant 4/4. You are right. Necks and headstocks are from 4/4 . My point was supposed to be that for thicker pieces the tablesaw won’t be able to make it through. I do all my necks by cutting them by hand and then planing them by hand. It’s just easier. You can make a sanding block and sand them dead flat if your hand plane skills are not the best. The angle doesn’t have to be perfect - but the faces must mate completely.
What I have been reading is you make a guitar neck from a 1" thick piece. Have a 12" rip blade for the Hammer saw, was trying to figure out a way to use the sliding table to make the cut, thinking a 10 degree cut is not far from ripping a board.
No matter how nice the cut is on the table saw, it likely will not be “glue ready” off the saw. Scarf joints need to be perfect. I use a jig that cuts the angle on the bandsaw, then cleans up the gluing faces on a disc sander. You can do without the bandsaw jig; just freehand it. For the disc sander jig, glue a board onto another board at the desired angle, then use this as a guide for feeding the workpiece into the disc. It’s so easy, if feels like cheating. If you don’t have a disc sander, you can block plane the faces flat and square, but it takes some time. The disc sander takes seconds, once you build the jig.
If you're trying to cut it on the table saw, you'll have to hold the pieces vertically. There's no way to get the blade to tilt far enough to register 10 degrees from the horizontal.
I've always used Roger's method to cut and true up a scarf joint. You can also true up the cut surfaces with a disc sander, if you have one.
Rick
Guitar neck thickness should be less than the blade height, so you can lay the piece on it's side on a sled at a 10 degree angle to the blade and push it through safely and accurately.
For scarf joints in material less than 3 1/4 inches I use a purpose built sled as described by Roger and Chris. I get a light prof joint right off of the saw. If needed the joint can be touched up by lapping on a surface plate
Attachment 484449
You just need to make a custom sled that can attach to your wagon so that the workpiece is held steady and vertical through the steep angled cut. Be sure that the offcut is also supported with some material on the saw table so it doesn't start to fall near the end of the cut.Quote:
Originally Posted by Jim Andrew
Same here. With the beautiful wood in a lot of guitars, it is a pleasure to plane, and takes only a minute to get the surfaces mated. If I was moving up in production, to sell a few. I might consider a more refined process than a ripped scarf (very strong), and thereby pretty much lock in the hand tool approach.Quote:
Originally Posted by roger wiegand
When I got my 3D printer, one thing I found useful were small templates and squares. I figured I needed some specialized speedsquares for scarfs, and templates. Just cause why should the machine sit on it's hands. The printer is good at that kind of thing. But once produced they looked really insignificant, and they sorta disappeared into the general clutter.
Make a jig that will hold the workpiece and slide along the fence or use the miter slot. :) Hold the material very securely and make the cut very slowly to avoid stressing the band and causing it to move around because of that stress. Use a band that's designed for resaw work so it clears the gullets efficiently...you can dress the surface with a hand plane or other tool after the cuts are made.