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First time routing for p90 pickups and I've realized that the standard 1/2 cutting diameter template bit does not get tightly enough into the corners of the template, and the pickup will not fit into the finished cavity. I have been scouring the web for a 3/8" cutting diameter pattern bit and I cannot find one. I used one once in the past, so I know they exist. Does anyone have one, and if so, where did you find it? As a last resort I'm going to take the dremel to the edges of the pickup cavity but I really don't want to have to do that.

Well, the last place I looked, Stew Mac, has one. Strange I can't find a small bit like this anywhere else.

I use the Stew-Mac one too. Works great.

Could you use a straight bit and a bushing?

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Brian

You never know what you are capable of until you actually try.

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The thing about the Stew-Mac 3/8 inch router bit is that it's only suggested due to it's fragile nature for use on the corners of the P90 rout, so it has limited use. Of course, if you build many guitars using P90 pickups it may be worthwhile.

I used a "Power Grip" carving tool from Woodcraft to bring the corners on a P90 rout to a 3/8 inch curve. In the future, I would try a 3/8 inch brad-point drill bit after practicing on scrap first, drilling the corners first.

Just because it's 1/16" smaller than a standard router bit, I don't see why that would make it so fragile.

I am actually going to be looking to use it to do the corner p-90 routes in an aluminum pickguard.. Ever routed aluminum? I'd only be using a 1/16" sheet. Stuff is pretty soft, at least as far at metal goes.

Like a dope I attempted to open up the corners of my existing p90 holes using a dremel. It is not horrible looking by any means but it is not perfect. So, classically, I am looking to now hide the routes. Why oh why did they ever manufacture p90s with 3/8" radius corners?

Just mentioning what is said on Stew-Mac's website about the 3/8 inch router bit.

"We recommend that you use the 1/2" bit for the bulk of the work, and the 3/8" for touching up the corners only. The bearing on the 3/8" bit is very delicate, and will not hold up to the work necessary for the entire cavity."

Oh I see.

I go free hand when routing pickup cavities.
I use a small laminate router with a spiral bit.

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wah
Wah-wah-wah-wah
Wah

That's fine if you are using a pickup ring to cover your hideously routed cavity. But P90 pickups traditionally do not use rings, so the entire perimeter of the cavity is exposed and there should be a perfectly clean transition from top wood to pickup.

Timely topic, as I am about to do my first p-90 rout also.

How about drilling the corners first with a 3/8" brad point or forstner bit, routing with the bit you have, and then when you have the straight edges established use a chisel to shave off the small remaining bit of wood.

It can be done of course, but will you make it look perfect? How much time will it take? I just debated for awhile and finally coughed up the 26 bucks for the router bit.

Definitely the most reliable way to go, if you have time to wait for the router bit to arrive.

"We recommend that you use the 1/2" bit for the bulk of the work, and the 3/8" for touching up the corners only. The bearing on the 3/8" bit is very delicate, and will not hold up to the work necessary for the entire cavity."

Probably good advice but I don't use any bit for all of any cavity. I drill out 90% of all my cavities with Forstner bits and just clean up the edges and make it full depth.

^^^^^^
That right there.
For what it's worth, I recently installed a set of chrome covered pickups in a pickguard on a recent build. The standard rout with a 1/2" bit would not allow the top of the pickup to come through the 'guard because of the corners of the pickup cover.. My solution was to use a 1/4" straight router bit for the corners. Since the shank is the same diameter as the cutter, no bearing was necessary, and it worked like a charm. I think it would probably work for your situation as well, and I bet you've got one lying around for truss rod routs, etc..

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Mike

The only thing nescessary for evil to thrive is for good men to do nothing.

The 3/8th bit and bearing work fine for routing the whole cavity. I've been using the same one for several years now, quite a few cavity routes.

If you don't lubricate the bearing, it gets hot and blows up.

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Old growth, shmold growth!