I was self-employed as a machinist in the early '90s when I was 'between careers' as a result of the recession. I still have the skills, but I only recently found a contact that can give me access to a small shop to do some personal work in.

This is not something you should try as your first do-it-yourself guitar modification. You should probably start your search with your favourite guitar tech or luthier. I doubt you'll be the first player to approach them with a request for some custom work. Ideally, the tech will already have the contacts and skills to handle the whole project, or as much of it as you want them to look after for you. From there, it comes down to balancing your abilities to do the work yourself, with your willingness to pay someone else to do the work for you. There are five main cost-centres to deal with: 1) design, 2) materials, 3) machining, 4) finishing, 5) Installation/Setup.

[u]1) Design[/u]:

You can save major bucks by doing this part yourself, because there's a lot of labour involved. To duplicate the 'tone block' I installed in my '62 re-issue Jap-Strat, you have to pull all of the pieces off of your guitar, and carefully measure the tremolo pocket.

A more economical approach would be to remove just the back cover, and measure the gap between the guitar body and the tremolo block that the springs attach to. Locking the tremolo is not as effective as replacing it with a solid block, but it is cheaper, and it's easier to [u]un[/u]do if you decide you really miss dive-bombing.

You have to communicate your needs to the machinist in very clear, un-ambiguous terms, so that you don't end up paying for a fancy paper-weight instead of sonic ecstacy!

Machinists work in "thou", as in thousandsths-of-an-inch, so you need to have precise dimensions of the piece you want made. A 3-D sketch helps in visualising what the finished piece should look like, but what the machinist will really need, is a proper mechanical drawing, showing the top, front, and side views, with all dimensions clearly referred to the appropriate features. Some time perusing a good book on mechanical drafting may be in order here. Did I mention that this is not a good candidate for a first project?

[u]2) Materials[/u]:

I prefer brass for this kind of application. It's fairly easy to work with, it has just the right density to give me the result I'm looking for, and it pollishes up very nicely. This isn't important for parts that remain out of sight, but pride in workmanship counts for something. Steel will also do the job well, but unless you plan to plate it, you will have serious rust problems in the not-too-distant future. Paint is not a good option for this application, because the block needs to fit as snugly as possible, and pressing it into the pocket will scrape it off,leaving exposed metal. Aluminum is easy to machine, but the sonic properties tend to be kind of shrill. If you want lots of squeally overtones and harmonics, that may be a good thing. Me, I'll stay with brass.

If you don't know anyone who does this kind of thing, you can start looking for sources with the Yellow Pages of your phone book. You want to find a supplier who is willing to sell a small piece of stock across the counter. Since you will also need to find a machinist, call machine shops as well. Some shops only do large production runs, but they all have bits of stock left over, and you can probably get what you need at a reasonable price.

[u]3) Machining[/u]:

If you haven't already found a machinist while you were looking for the material, hit the phone book again and search out shops that are willing to do small 'one-of' jobs. The high-volume production shops won't touch a job like this, but they may be able to refer you to someone who will.

[u]4) Finishing[/u]:

This is another excuse to prowl around the industrial parts of town. Shops can usually handle small parts for chromate, copper, nickel, chrome, or gold plating. Aluminum parts can be anodized or irridited, as an alternative to plating. If you want a smooth finish, this will have to be done before the plating. Plating will not smooth out a piece that has scratches or file marks on it. This is another area where you can save some bucks by doing it yourself. And if you want something polished, be prepared to spend some time getting familiar with the subtleties of Q-tips, Brasso, and a Dremel tool.

[u]5) Installation/Setup[/u]:

If you did evrything on your own to this point, you can probably do this part for yourself, too. Most of us will need to enlist the services of a guitar tech or a luthier... you know, the first person you approached with this project? :)

Good luck,
L.