Compenstaed nut jig

[Dave M]

I realise we have had some discussion on this before but I thought people might be interested in my attempt.

I didn't have any brass angle strip and the lockdown makes it a bit hard to get such things so I thought I might be able to bodge something as compared to Trevor's nicely engineered jig.

I bent a piece of brass strip to grip the nut blank.

Having got the little brass blocks cut and hole threaded it was clear they were not very evenly arranged - fairly rough engineering here. But by pushing them forward a bit proud of the front face of the jig I was able to file them flat - you can see the file marks here.

Finally the side bolt was not enough to keep the blocks locked ( I didn't have a means to capture the bolt heads) so a block behind the bolt heads keeps them in place

First go at cutting was very rough Took a while to remember to change to top speed on the drill press. It also occurred after a while that practicing on nut blanks was going to get expensive so sized up some maple. Rather to my surprise it did work:

If a bit rough round the edges. I went this route because I really couldn't think of an alternative means of doing this shaping. Oh and Trevor told us to!
Hope this might help people who are considering a go at this. It is doable in an ordinary shop.

Trevor if by chance you read this I wonder what cutter you use? I used a two flute router bit and it is a bit aggressive. I suspect a burr of sort might be better.

Cheers Dave

[Trevor Gore]

Trevor if by chance you read this I wonder what cutter you use?

CMT 1/8" two flute solid carbide down spiral. A new one can be pretty aggressive, so I use ones passed down from other operations (e.g. rosette channel cutting). I run a low speed on Tusq, otherwise it melts. Bone could be run at a higher speed I guess, but I tend to use the same fixed speed (on my 16 speed drill!) for everything. Up spirals work too, but remember to completely lock the quill or the bit it will screw itself down into the job.

[kiwigeo]

Haven't got to jig stage yet. I'm still frigging around with a spreadsheet to work out nut and saddle compensation values.

[Dave M]

Thanks Trevor.

Martin I have sort of done it the wrong way round - haven't done the calculations yet. But am thinking I might just try the average figures Trevor quotes in the book and see what it sounds like.

Cheers Dave

[AKEric]

I have had luck with the Speed Tiger milling bits. Price is pretty good:

https://www.amazon.com/SPEED-TIGER-Carb ... JLMJ5?th=1

I, too, am still wrapping my head around this nut compensating concept.

[kiwigeo]

I have the modeling of the neck and fretboard down pat. What I'm trying to do is to jig up a spreadsheet where I can play around with nut and saddle compensation and get a plot of out of tuneness for different combinations of nut and saddle compensation. I then pick the plot that shows minimum out of tuneness. The problem is somewhere in the coding of the spreadsheet.

Thanks Trevor.

Martin I have sort of done it the wrong way round - haven't done the calculations yet. But am thinking I might just try the average figures Trevor quotes in the book and see what it sounds like.

Cheers Dave

[Dave M]

Thanks Eric. Do you have adjustment on your jig or have you gone for fixed size blocks. I guess if you know how much to take off this would be much easier to construct.

[AKEric]

Hey there Dave,

I used individual UHMW blocks for the steps, and can adjust each one. It's just about like Trevor's model. A bolt from the end squeezes them them together and holds them securely in place. So far, I haven't been using Trevor's most accurate method, but getting fairly good results.

Eric