Installing a K&K internal with a James tailpiece

I wanted to add a note for folks installing a K&K internal pickup on a mando with a James tailpiece. I did the research here before the install and I saw conflicting info on whether or not you have to enlarge the the James tailpiece hole to fit the K&K jack.

Here is what another cafe member and I found last night during the install: You DO have to drill the James to 15/32 same as the mando. If you don't enlarge the the hole in the James, you will not end up with the requisite 1 or 2 K&K jack threads protruding from the strap button.

The reason for having 1 or 2 threads showing is to ensure that the the plugged-in cable fully seats into the K&K. From what I read, it may work fine without 1 or 2 threads showing past the strap button, or it may not. Or it may work fine for a while. In order to get the protruding threads, you'll have to enlarge the hole in the James to the same size as the drilled mando block (15/32).

Another pointer is definately use a good step bit to drill both the mando and the James. You'll have to finish the mando with a regular 15/32 bit (otherwise you'll have a tapered hole). The James is thin enough that the step bit alone did the job. But the brand new step bit did a beautiful job of drilling both of them smoothly and cleanly with no binding, tearing, splintering, or other drama whatsoever. Absoliutely no pucker factor at all! Highly recommend using one.

With the great help I had, all went extremely well and yielded a professional quality result. Very happy all around.

I installed a K&K in my Eastman MD315. I started off trying to enlarge the tailpiece hole with a hand reamer, but ended up buying a good step bit. I was amazed how easily and cleanly the step bit enlarged the hole in the tailpiece. I didn't follow with a regular bit - any tapering of the hole didn't seem to be a problem with installation of the end-pin jack. I was thinking about upgrading to a James tailpiece but have decided I didn't want to mess with that K&K end-pin jack anymore. Working through f-holes isn't my favorite form of entertainment! :)

Plus one (10) on the step drill. Hard to justify for just one install, but it's cheaper than repairing the potential disaster and near heart attack frame of mind using a regular drill bit. Get a step drill that stops at 1/2" so you don't have to hold back. That extra 1/32" causes no problems. Once you're through, you can use a regular bit or file to enlarge what the step drill didn't get to.

One other pointer- most hardware stores will probably carry some rotary files that you can chuck up in a drill. I have one that is 1/2" outside diameter and is cylindrical for most of its length, but has a tapered rounded front end that fits nicely into holes even a little less that 3/8". No pucker factor with that either.

You would think that James and other tailpiece makers would have an enlarged hole as an option.