Razor saw

[Edwin]

I've been looking at various "razor saws" on the web, but only one - which looks like a razor blade with teeth - gives the blade thickness (0.006). I want to cut notches in bone to locate guitar strings and the maximum cut for the thinnest string should be no more than 0.3mm (.012") and preferably not much less. For the rest of the notches, which become progressively wider, the same blade could be used, together with small files. The Tamaya looks good, but I can't find the crucial measurement. The length of the blade isn't very imprtant for this job. Any information or advice?

Edwin

 

[MIGNAL]

It's pointless doing a top nut notch that thin with a saw. Much easier to use a very fine round needle file and of course you get the correct profile. It's just a few strokes with the file, you are only going at half (or just over half) depth. Just be mighty careful with the tip of the needle file, extremely light pressure.

 

[KevM]

Have you looked at the zona http://www.zonatool.net/35-550.html razor saws? The fine kerf saws have a kerf of 0.01", Chronos and Workshop Heaven carry some Zona, together with some model shops - and they're surprisingly inexpensive.

Kev.

 

[Jacob]

Wouldn't cutting a V with a sharp chisel do it?

 

[TobyC]

http://www.stewmac.com/shop/Tools/Saws/Gauged_Saws.html <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

https://www.youtube.com/watch?v=mURaYb9S3iM

 

[Edwin]

Thanks for the advice and references, which I've followed up/thought about. The snag is that pukka files would set me back £65 - £70, which is a lot to add to the cost of a single guitar. There are cheaper sets on eBay but from halfway round the world and no dimensions are given. I happened to find an American forum for Telecaster enthusiasts in which one guy says he made a set of files from feeler guages, using a Dremel to form an abrasive surface on the edge. It seems a brilliant idea and, as one of you says, there's only a small amount of material to be removed - once you're within half the string thickness of the bottom of the notch. I've long stopped using feeler guages that I first had for an Austin 7 Ruby, so I'll give the idea a try.

 

[John Brown]

Wouldn't cutting a V with a sharp chisel do it?

V shaped slots are not a good idea, as the movement of the string(especially a wound one) will cut a deeper slot more easily.
I just bought a set of nut files, and they weren't cheap, but I looked at all the options(there are folks selling welding nozzle cleaners on eBay and Amazon that are supposed to work after a fashion) and decided that I would get the proper tools. Of course, true to my nature, I haven't actually got round to fitting my replacement nut yet, but as I dream of making a few guitars when I grow up, I thought the investment would be worthwhile.

The only thing I don't understand is that when I did this sort of stuff years ago, I seemed to get by with virtually no special tools. I think it's a manifestation of that rule that states "if you don't you can't do it, you'll go ahead and do it" or something similar.

 

[Cheshirechappie]

It might be wise to be a tad cautious about quoted blade thicknesses for saws. The set on the teeth, even if very slight, will mean that the kerf is wider than the blade. It might be a good plan to cut a kerf in a piece of scrap and check it with the feeler gauges.

There are many types of small file available, especially from clock and watch equipment suppliers. A round escapement file (they're tiny!) from someone like Cousin's Material House might be a better bet.

Edit to add - https://www.cousinsuk.com/catalog/tools ... orbe-swiss

 

[thick_mike]

I made some from feeler gauges. They don't cut very fast...which is a distinct advantage!

 

[Jacob]

Wouldn't cutting a V with a sharp chisel do it?

V shaped slots are not a good idea, as the movement of the string(especially a wound one) will cut a deeper slot more easily.

Wouldn't it merely file its slot to size? As you say - how were these things done without special tools?

 

[thick_mike]

Wouldn't cutting a V with a sharp chisel do it?

V shaped slots are not a good idea, as the movement of the string(especially a wound one) will cut a deeper slot more easily.

Wouldn't it merely file its slot to size? As you say - how were these things done without special tools?

The height of the bottom of the slot needs to be very accurate. If you position the string in a V slot it will sit just above the bottom of the V due to the string having a circular cross section. With only two points of contact strings will wear the V away to become a U shape. The string sits lower in the nut and you can get fret buzz on the open strings. The difference between a fast action on a guitar and fret buzz is very small and depends on your playing style too.

Like I said, I used feeler gauges with Vs cut into the as very inefficient saws. Because they cut so slowly, you are less likely to overshoot. If I was doing it every day I would buy something from Stew Mac...but I guess I'll only do one every three years or so, so speed isn't an issue.

 

[Tony Spear]

I know very little about guitars (playing or making), but I would think that to cut the notches you need, you could do it perfectly well with a guitar string of the right diameter coated with grinding compound and then work it gently backwards and forwards until it's a perfect fit?

But there again my name is Manuel...... :lol:

 

[John Brown]

Wouldn't cutting a V with a sharp chisel do it?

V shaped slots are not a good idea, as the movement of the string(especially a wound one) will cut a deeper slot more easily.

Wouldn't it merely file its slot to size? As you say - how were these things done without special tools?

That would probably be OK if you have a fret at position zero, as some guitars do, but otherwise, as Mike eloquently explains, it will result in the string sitting lower in the nut, and thus buzzing on fret one.

 

[David C]

The advantage of the Zona saw is that it is not expensive. About ten quid? I can think of several Japanese saws but they will be over 30 quid.

0.01 inches, is ten thou, which is about 0.25mm. There will be some set, but if too much it can be reduced with a slipstone.

David Charlesworth

 

[TobyC]

You might be able to work with these.

http://www.tamiya.com/english/products/74111handycraft_saw2/top.jpg

"★This small tool is exceptionally useful in the construction and modification of plastic models, Mini 4WD kits and so on.
★The fine teeth on the blade ensure that the saw cuts with a minimum of effort and leaves a clean edge when done.
★Blade lengths: 46mm (wide blade), 43mm (narrow blade). ★Comes with a plastic case for storing blades safely. ★Blade material: Carbon tool steel SK95 (0.35mm thickness)"

http://www.tamiya.com/english/e-home.htm

Or just look at your local craft/hobby store.

 

[John Brown]

0.35mm is a bit big for "most" top E strings, I think.

 

[thick_mike]

Yes, 8s are about 0.2mm diameter.

 

[MIGNAL]

Like I say, fine round needle file. I've done hundreds of Top Nuts with one. Simple and much cheaper than the joint round edge files. Just get a decent Grobet/Vallorbe. Practice on a few wood blanks first. The feeler gauge idea is a very poor substitute. There is no way that teeth cut into a feeler gauge is going to cut a smooth slot into bone.
The other alternative is a Pippin file. The one that LMI offers isn't very good for doing fine strings.

 

[Jacob]

......
V shaped slots are not a good idea, as the movement of the string(especially a wound one) will cut a deeper slot more easily.

Wouldn't it merely file its slot to size? As you say - how were these things done without special tools?

That would probably be OK if you have a fret at position zero, as some guitars do, but otherwise, as Mike eloquently explains, it will result in the string sitting lower in the nut, and thus buzzing on fret one.

So you cut a v slightly high and run it in?
What happens if you change string gauge?

 

[Kalimna]

Mignal - as I will (at some point over the next few months) be cutting a pair of ukulele nuts, I wonder if you could point me in the direction of somewhere to purchase suitable files? I have managed (with just a few short strokes) to totally pineapple up a tusq nut for one of the electrics I made, using razor saws. I like the idea of using a round file - seems slower and more accurate.

Jacob - another issue with using a v-channel to sit a string in would be a tendency to cause tuning instability. More so on wound strings, however. And whilst Ive never tried it, Im not sure how easy it would be to accurately cut fine notches into bone or tusq with a chisel.

Cheers.
Adam