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Does anyone have a good method or jig to thickness a nut or saddle evenly? I usually do it freehand on a piece of sandpaper stuck down to a flat surface, but I find it a bit difficult to keep it even. Usually one edge or end will get thinner than the other and then I have to lean on the other edge to try to even it up. I am aware of the SM Nut and Saddle Sander tool, but it appears to only be useful for sanding the bottom. I don't have any problem with sanding the bottom, just interested in coming up with a better way to sand the sides.

I use a Luthier's Friend in a drill press, Barry.

I stick mine to a small block of wood (the handle) with double-sided tape and freehand it on the belt sander. Yes, I have to go back and adjust for tilt. It takes a bit of patience because I only do a little at a time until it’s just right.

Just done these, I stick mine to a small stick (10") of wood with double-sided tape and run it though my 10-20 drum sander (150 grit) to about 0.1/0.15 mm thicker than what I want and finish by hand on a glass plate with sandpaper up to 320 grit.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Same here - drum sander, with the part taped to a carrier.

Drums sander if I need to hog off thickness, or a benchtop oscillating spindle sander. I have a mag fence on the table for quick adjustment, and push the saddle between fence and spindle with a sacrificial push stick.

But much of the time I find I can just keep stock of a range of different thicknesses and one is usually close enough for most factory made guitars that I can finish it by hand without having to do so much sanding my arm falls off.

Also I find many factory instruments have slots of inconsistent width, and if the job doesn’t call for milling the slot true, then hand sanding has the advantage of being able to sand one end thinner than the other etc as needed.

I run mine through my Supermax drum sander to rough them to thickness. I take them to within 005-.006” then finish thicknessing them by hand on a flat plate with 3M gold paper stuck to it. The trick to doing this is to use a follower. In my case a scrap of wood about 2”x 8”x 1/8”. Running the nut or saddle lengthwise, as you would imagine, place the scrap flat on the conveyor right behind it, and follow it through. I find an 1/8 turn with 120 grit paper works nicely.

M

Double-sided tape for me too on the drum sander. Also, I have a gauge made from bone of the desired thickness stuck on the carrier close to the work pieces. That gets marked up with a pencil -- when I see the slightest evidenced of sanding contact with the gauge block, I know I'm where I need to be.

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formerly known around here as burbank
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http://www.patfosterguitars.com

Push stick and fence on the roller of my edge sander…

Believe it or not, I do it freehand on my 6 X48 sander...

I can get it within a thousandth or two of what I am shooting for.

We are all freehand on Dan Erlywine's Dad's belt sander (we have this fine old tool of his) with 80 grit paper and no safety guard on the open end so we have to stand back or we may have more problems with our nuts than we wish for...

I stand there will a dial caliper and because of experience doing this daly I can get the job done pretty accurately and fast. I know in advance to get close and then I move to a leveling beam we use for fretting and sand the nut or saddle on 220 paper to get the 80 grit scratches out.

We finish with our nut buffer that makes them look all shiny and new.

We trial fit and then sand a bit more until our saddles are a bit snug and our nut blanks "snap" into place with one drop of CA required once the nut is competed only as insurance because of the snap fit.

We are retrofitting existing guitars making every nut and saddle different and requiring an individual, hand's on approach. Working to spec would not work in our work.

So what Bread said, we do the same and can get within a thou too but I stay several thou larger to leave room to use 220 on a leveling beam to get rid of scratches.

For holding say a saddle you can make a jig with a board and an end stop of various thicknesses. I usually do it by hand though same with saddles.

I rough thickness with the Gilbert disk sander on my drill press and fine tune with a little jig I made years ago that has a recess for a nut on one side and a saddle on the other. It works on sandpaper stuck to a glass plate.

I have also used the thickness sander and double sided tape as mentioned by others to rough thickness.

83F8401D-0D3C-4962-901D-A8E36C8D114E by Terence Kennedy, on Flickr

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It's not what you don't know that hurts you, it's what you do know that's wrong.

This helps me. Flatten a face and square the bottom to it on a flat surface with stick-it sandpaper.

Then stick in the jig pictured with a drop of CA to hold it and sand uniformly thickness, then polish.

Simple but works, dial in the thickness with a set of calipers and it can be very accurate.

Had a wider one for saddles but it's disappeared, gotta make another one and write a note on it!



How come a good share of bone blanks come warped anyway!? Always disappoints!

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Brian R, Wood Mechanic
N8ZED

I dress bone the same way I dress all small parts (bridge blanks, headplates, etc.): through the thickness sander on a short carrier board with low back stop and whatever grit is on the machine. The surfaces come out parallel and flat. Final dressing is by hand on a sandpaper board up to whatever grit. The right angle for the bottom is dressed with the saddle/nut sanding skate, on the same sandpaper board. No tape, no special jig, no set up required. Ready for top shaping.


Sent from my iPad using Tapatalk

OOO! I like Brian’s holder. I’m going to adopt that.

Thanks to 'Rbuddy' for inspiration. I have a couple of disc sanders....

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Peter Havriluk

In the past I have used the belt sander or spindle sander and then to the surface plate with fine sandpaper with no issues. But the last few have gotten way out of parallel before I noticed. Don't know what I am doing differently. My machinists mind seems to insist that there should be a way to dial in the thickness I want and have full control during thicknessing.

Nuts are less of a problem than saddles. Saddles are hard to hold and the sides have to be truly parallel.

Thanks for the ideas guys.

I use a plane jig, similar in some ways to Terrence's holder.

Take a piece of plywood and glue two pieces of wood to it that are just over the thickness you want the saddle to be, with a gap in between them as wide as the saddle is tall. Glue a stop in the gap for the saddle blank to push up against. Then glue two strips of wood down along either side that are just far enough apart for a block plane to run in between them. Drop a piece of bone into the slot and plane on it. The plane will stop cutting when its edges are riding on the wood on either side, and the saddle will be the same thickness as the depth of the slot minus one plane shaving.

I find this works best with something like a Stanley low-angle block plane (not the 'Sweetheart' model). The 'nicer' planes use harder steel in the cutter, and it tends to chip on the bone. The softer steel in the Stanley cutter holds up longer because it's tougher. It does have to be sharpened fairly frequently, though, and short bevel really helps.

I was taught to make the nut slightly tapered (.2- .3 mm) in width as seen from the top, so that it slides in from the bass side of the neck and wedges in place in the slot. This holds it in if the guitar is totally unstrung for some reason, but makes it easy to remove, and there's no need to glue it. The jig for that is easy to make; just taper the side pieces to change the depth of the slot from one end to the other.

The jigs will also hold pieces of bone that are fairly rough on both surfaces, so you can flatten out one side, than then flip it over to thickness it.

I use the same sort of jig to make rosette parts. It's not hard to get very high accuracy this way.

I like to taper them too. Sure makes it easy to work on.

I had no idea you could plane bone! Thanks Alan.

When I have just a hair’s width of bone to remove, I scrap with a razor blade.

That's the way I do it to and I think I picked up that trick here on the forum. I use a belt sander to rough it in.

For the OP fwiw here's making a saddle. https://www.tiktok.com/t/ZTdK2uErt/?k=1

I use a little Harbor Freight milling machine with a spiral end mill and a standard milling vise. I used to do them with a carrier and my drum sander, but the mill leaves a really nice shiny finish and doesn't take any longer to do. Same machine I use for cutting saddle slots in bridges and many drilling operations. Always stays parallel. Heck, I have the machine, might as well use it.

Dave

Dave, are you able to dress a saddle with the mill? Seems like the thickness of a saddle would make clamping in the vise a bit of a challenge.

Yes--no different from milling thinner pieces of metal. I use parallel bars in a milling vise under the bone. Works fine. An alternative could be to double stick tape the bone blank to a piece of wood or use one of the other jigs mentioned in this thread, but using a milling machine in place of a sander or plane.

Dave

As a follow up: I was inspired by Terance to make a holder for the nut or saddle blank. It seemed like the holder would increase the ability to hold the bone flat and not end up with a wedge shape. I made my holders by gluing up layers of Plexiglas. For a recent Tele build I needed to get a nut thin and accurate to fit the nut slot. So I added some guide strips (scraps of plastic binding) to the holder which got sanded away as the nut approached the target thickness. I added a couple of pieces of a popsicle stick to keep the bone in the holder. This worked quite well. Thanks to everyone contributing here.