But buy one from ebay, not SM.
https://www.ebay.com/itm/313637041764?h ... R9aS2I3bYQ

Not sure I understand the question. Saddles are sanded free hand on belt sanders as a matter of course for those of us who repair guitars. I do it daily.

A picture would help and always does on this forum, thanks.

Regarding the tool it would be a time waster for us we do it freehand and that's not difficult to do.

So it's a conventional, compensated saddle with differing heights treble to bass sides.

With this said we measure and mark, I use a very thin pencil and we drop action (or raise it) around 1/64th" at the 12th fret for every doubling of that, 1/32nd" inch we raise or lower the saddle at it's bottom.

Now I know you are more concerned about keeping things straight up and down on the sander, correct? If that's the case you can practice milling saddles with wood blanks, scrap bone, counter top scraps, lots of materials.
.

Sol here is how I professionally manage the relationships between the nut, the neck and relief and the saddle.

The first thing I do when setting up guitars and I just finished three of them is to set the relief (truss rod). Once I like the neck shape I cut the nut slots and that's an art where experience greatly benefits one. The last thing I do it take material off the saddle (or raise it with a new saddle or shims).

So the pint here is I never even look at what I have to do to the saddle until the relief is set and nut slots are cut properly. This way you never have to back track to these things again they can be correctly set in isolation from the saddle.

Now keeping the saddle perfectly flat on the bottom is important and good on ya for being keen to do just this. Consider using something very flat in your shop (surface plate, leveling beam, table saw table) with 220 sand paper stuck to it to sand the saddle bottom for straightness. I use a belt sander, Dan Earlywine's Dad's belt sander to be more precise we have it in our shop. I use the belt sander to hog away material on the saddle bottom and then I clean it up on a flat surface making pencil marks and sanding until they are ll gone.

Hope some of this helps Sol.

Wow, that is unbelievably low action! Is that measured at the 12th fret with open strings?

Is that the current action or your target action?

Pat

Hey, Dave.... This is only done for my most sensitive clients, guys with the absolute lightest touch. Mostly fingerstyle guys, but I have done it on electrics, too.... I have one for sale if you want it...

I do it the hard way on new guitars.... I grind the frets down to the correct height of .025, which sometimes takes DAYS if it had medium jumbos (I'm a part timer, ya know). What takes forever is crowning the frets which have now been flattened out considerably.

I use a StewMac 3 cornered file, a couple reworked Swiss die sinker files, a StewMac sanding stick, and one of those stainless StewMac fingerboard guards. I radius first from the bass side, then turn the guitar around and radius it across the fret from the treble side. Then I use 3 different grits of sandpaper to blend it all together. As you well know, with a fingerboard guard which measures .010 thick, or blue masking tape (about .007 thick), that doesn't leave much room at all to produce a full radius when crowning. I seldom achieve a perfectly round fret crown, but it's pretty close.

Frankly, it's a cast iron b*tch to do, which is why I charge triple to do it. It uses up a lot of tool and supplies, a bunch of my epidermis and even part of my fingernails. My fingers hurt for a day or two after I'm done.

And then I string up the guitar to pitch, and leave it for a day to settle. For setup, I adjust the truss rod almost perfectly straight, and check it several times over a few hours until it has settled. As you know, the lower the action - the less wiggle room for mistakes. When I'm finally satisfied, then I capo it at the first fret and lower the bridge saddle as low as possible. I'm looking for stoopid low. I might have to shim it, but usually I can get it a taste lower even then. Then I pull the capo, and set the action at the nut - again stoopid low. And then, I let the guitar sit at tension for a couple hours and I check it periodically. IF the guitar needs it, I'll adjust the truss rod a smidge - and I mean barely. At around the 10th fret you MIGHT be able to slip a piece of folded paper (.008) between the treble E and the fret when the string is held at the first fret and last fret. Triple fold on the bass E (.012).

You want to know what stoopid low is, right? On the plain strings there's about .005 between the bottom of the string and the top of the first fret. About .012 on the wound strings, with maybe .015 on the E. At the bridge, the treble E is about .035 with each string getting a little more gap until the low E is about .055. Most cats can't even play it now without making it rattle - including yours truly. One of these guys can play SLIDE with it that low, and you'll never hear the slide hit the frets. He's a spook.

On used guitars, I pull the old frets, sand the fingerboard perfectly flat. I refret with the tiniest mandolin frets I can find on Amazon. They are about .037 tall to start. Not much meat to remove, but I still have to do the radius thing.

I can't remember if I posted these pics from another Taylor I did for the spook (I've done 4 jobs for him).
Note there is no tape inducing tension in the strings. Under the treble E, a penny is held upside down by string tension only. It's a nickel under the bass E. I figured gravity would pull them out....

https://imgur.com/aOdaWN4

https://imgur.com/PjEcmyL

https://imgur.com/XftcseF

https://imgur.com/oLzlb7Q

Most of the cats remove the truss rod cover after this mod. This is Kansas after all, and the least change in humidity or barometric pressure makes the action move a bit.

Sounds like the OP got the problem solved but I just did one today so I took a few photos to share. This was for an OM and the hi E needed to come down 1/2 of a 64th (about 0.0075") and the lo E needed to come down a whole 64th (about 0.015"). Difference on the saddle is twice the difference at the 12th fret so saddle needs to come down 0.015" on the hi E and 0.030" on the lo E. This is one way to do it.

1. I just use my calipers to scribe short lines on each end of the saddle, 0.015" on the hi E and 0.030" on the lo E. I use a pencil to highlight the line so it's easy to see.


2. If the bottom of the saddle isn't square I just put it up against a wood block and square it. I do the sanding on an inexpensive granite surface plate with 120, 220 and 320 sandpaper on it.


3. If the bottom of the saddle is already square I just do it by hand. In this case I want more off on the bass side so I put more pressure on that end. Check it often and that's all there is to it.

I'm happy that there are those who can eyeball the things a saddle needs. I can't.
One of the nice things about the noted tool is the calibrated posts in the middle of the tool. These let you make 1/64" adjustments based on the action measurements you've taken. It's just simpler for us newbies.

(Here is the one I bought. https://www.ebay.com/itm/124813457131)