Stop piece placement?

Hi everyone!

I am about to drill bushings into a kit for the first time and I am a little nervous. I got an 11mm brad point drill bit and plan to mark my drill marks with digital calipers to ensure precise spacing. I am installing a Gotoh stop piece with bushings (the GE101Z). The diagram is here: https://g-gotoh.com/images/pdf/GE101Z-Dim.pdf

Based on that diagram, I believe my bushing holes need to be 82mm apart (if someone can verify, that would rock!), but I do not know what distance the stop piece should be from the TOM bridge.

guitar is a trini model as shown here: https://imgur.com/U6IdAIt

Any idea what the distance should be from the TOM bridge to the stop piece? Also - does the depth matter? I don't want to go deeper than I need to, but if it's too deep, will it create issues with the bushings? I think there is a lip on the bushings to prevent it from going in the drill cavity but I am not 100 percent certain because it looks to be very slight. My plan is to tape over the drill bit so I know where to stop.

Any advice in drilling these would be appreciated! I don't have a drill press so I am going to try my luck with a power drill and straight/steady hand. Let me know if that's a huge mistake!

Thanks everyone

Yes, centres are 82mm apart.

The distance from the stop piece to the bridge isn't too critical; it doesn't want to be too close or the tailpiece will need to be set high to avoid catching the strings on the rear of the TOM, but it can be set quite a long way back if you want.

On my 1998 Les Paul, the centres of the bridge and tailpiece posts are roughly 40mm apart. On the Pit Bull ES-1 kit it's 43mm and on my Yamaha SG1000 it's 50mm. So there's no one value that's set in stone. Anywhere between 40mm and 50mm should be fine.

You want to drill the holes as vertically as possible. Don't use a block-style drill guide as you'll end up drilling at right-angles to the body surface, and being arched, the posts will then splay out when fitted. They want to be vertical so the posts stay parallel. Get someone to help you keep the drill as vertical as possible by checking from the side when you drill. Support the body at the edges so it stays flat (with a curved rear it's liable to angle over when pressing down off-centre).

You'll want the hole to be a tiny bit deeper than the insert. What you don't want is to end up fitting the insert only to find that the hole is 1mm too shallow and you then need to remove the insert and drill again. Apart from your hand resting on it, after it's fitted there is no downward pressure on the stoptail or bushings. It's all forwards and upwards from string pull.

If it has a rim, the rim will stop the bushing going too deep. If it doesn't have a rim (you get both types of bushings though the Gotoh one linked to seems to be rimless), you have to be a bit more precise with the drilling depth. Even then, it's best to have the bushing sitting slightly below the surface (but only just), rather than slightly proud.

However, just be careful when tapping the post in and stop when it's flush with the top. You don't need to tap it right to the bottom of the hole. I either fit an M8 bolt with a large head, or an old stoptail post, and hit that, rather than the insert directly. Definitely mask and pad around the hole when knocking the insert in to minimise possible damage from slippage.

Thanks, Simon! I was very careful, but I did deviate from your advice a bit by using a drill guide. I attached a magnetic level to the guide, propped it up flush with some thin cardboard, and tried to keep it as stable/even as possible. I figured that was a touch more reliable than eyeballing it given the curve of the body. Anyway - I believe it was a success! The posts seem to hold up the stop piece at the correct angle although I did not tap them in all of the way yet.

That brings me to another question - neither the bridge posts nor the stop piece posts slide into the holes. I assume that is because they need to be gently tapped in. The manual says to wrap them with tape and slide them in, but I am unable to get them pushed in with tape and it seems counterintuitive to cram them in the holes with the tape if they need to be tapped in with a hammer later. Do I need to use force? I'm still in the "mock" build phase as I haven't yet found the time to get really into this.

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The manual says to wrap them with tape and slide them in, but I am unable to get them pushed in with tape...

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The tape is only wrapped around the threads of the post, not the splined bushing. The idea is to wrap enough tape around the post threads so it acts like the bushing holding the post in place and centred enough so it doesn't fall out, but secure enough that it can be used as a guide for tasks like neck alignment/angle and bridge placement or checking the height.

When it's time to install the bushings, they are friction fit, so some resistance is normal. They should not require any glue. They will indeed require tapping in with a small hammer (not a 3 lb sledge) and use a block of hardwood between the hammer and the bushing so you don't chip the plating or distort the metal.