How to Manually Thin Out Control Cavity...?

[beerbelly]

This whole idea just seems to be the riskiest of all choices, with all the wrong tools, with possibly a very poor outcome. Can you please explain why pots with longer shafts is not an option (other than your personal choice)?

 

[Leee]

Hey, come on.
We’re all learning something here.



This post will live for a long time.
Others will benefit.

 

[Knoby]

Well, it's got a center pilot... which in this case wouldn't really be used... but without that outside cutting spur, it will avoid having the spur grab the wood and cause the bit to get thrown to the side.

Without that cutting spur that most Forstner bits have, it's just a matter of securing the guitar body so it doesn't move, and then having control of the bit, drilling at slow speed, and not using much pressure. As I'm only looking to remove between 1/16"-1/8" maximum that shouldn't be a problem.

Just in case it doesn't work as well as I anticipate, I also picked up a flat surfaced grinding stone...

Between the two of them, I should be able to achieve the results I'm looking for...

Thanks for everyone's help with this... much appreciated...! ;-)

Please post video or pics of how you do it. It will be invaluable to myself and others.

 

[Knoby]

This whole idea just seems to be the riskiest of all choices, with all the wrong tools, with possibly a very poor outcome. Can you please explain why pots with longer shafts is not an option (other than your personal choice)?

Man, everybody knows that floating pots suck the tone and sustain out of the circuit. If the pots are not adequately secured to the body, they vibrate and and some of the frequencies and harmonics don't reach the output.

 

[Dimension12]

This whole idea just seems to be the riskiest of all choices, with all the wrong tools, with possibly a very poor outcome. Can you please explain why pots with longer shafts is not an option (other than your personal choice)?

In my case, I had ordered the pots and it would’ve been cost prohibitive to send them back and wait for new to arrive. Did mine during covid and money was tight.

 

[beerbelly]

Hey, come on.
We’re all learning something here.



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I'm out...

 

[NINFNM]

Well, it's got a center pilot... which in this case wouldn't really be used... but without that outside cutting spur, it will avoid having the spur grab the wood and cause the bit to get thrown to the side.

Without that cutting spur that most Forstner bits have, it's just a matter of securing the guitar body so it doesn't move, and then having control of the bit, drilling at slow speed, and not using much pressure. As I'm only looking to remove between 1/16"-1/8" maximum that shouldn't be a problem.

Just in case it doesn't work as well as I anticipate, I also picked up a flat surfaced grinding stone...

Between the two of them, I should be able to achieve the results I'm looking for...

Thanks for everyone's help with this... much appreciated...! ;-)

Without any pilot I think your tool will slide out of the target as soon as you press the button

 

[fretout]

Hey, come on.
We’re all learning something here.



This post will live for a long time.
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There seems to be a lot of improper repair jobs lately. Destroying a Reissue Les Paul in order to install a Chinese-made Nashville Bridge, routing pickup cavities wider to fit aftermarket pickups/batteries, and now routing the control pocket to install a pot that was evidently too short.

Anyone buying on the used market, make double sure to complete a teeth-to-tail inspection before you drop cash on anything.

The OP was kindly offered the correct answer earlier in the thread, and seems to be committed to a bad idea. Coming to a classified section near you soon…

 

[D'tar]

This is luthier corner. This is a relatively easy job to to fit short shaft pots if that is what you want. I do beleive also that long shaft are absolutely fine without compromise.

 

[diesel99]

I'd like to remove a little bit more wood from the control cavity of my Les Paul, to expose more thread on the pots I bought to replace the stock pots with. The stock pots didn't have much thread showing, and as long as I'm replacing the pots it's a good time to see about making the cavity slightly deeper, as well...

Does anyone know what kind of tool might be able to be used to manually remove some more wood from the control cavity that might be able to remove it evenly...?

You don't want to do this. Someone who owned my LP Heritage Standard removed wood from the control cavity, and that's why there are cracks on the fin ish on that instrument. Get the right pots.

 

[LeftyF2003]

This thread may well overshadow my angle grinder Tele mod thread...

 

[emoney]

Well, let me add some +1's to the "get longer pots" idea that was floated. At the same time, I fully understand how these internets work, and should you choose to go this route, two things; 1) Make sure you practice this process on something equally non-flat but far less expensive, and 2)use a sacrificial board under the guitar for the center guide of the Forestner bit to be able to grab into. Also, I've built a few guitars, cut several spots where the pots rest but have always....always.....used a drill press so I could have a least a little control. Doing this by hand, as in a powered hand-drill, make sure someone is helping by holding the guitar even if you think you have it clamped secure.

 

[beerbelly]

I'm back in...
Assuming this is a carved top LP, this would be a far less risky proposition if it were a flat top, like a Special, and with the bridge, knobs, switch and pickups removed. Then, if a drill press and a Forstner bit were used with the depth stop confirmed, it could turn out OK.

 

[lowatter]

There's a reason that long-shaft pots were used in the 1st place and are universally used for LPs. This is a black hole thread if all the advice freely given is not heeded. JMHOYMMV

Also, I wouldn't even THINK about messing with that control cavity if it were I.

 

[dspelman]

Hey, come on.
We’re all learning something here.



This post will live for a long time.
Others will benefit.

Especially from the post that says, "Oops."

 

[sdshirtman]

I realize this is a month old thread, but it caught my eye as I had to tackle this scenario a few months back. Maybe it will give someone an idea if they search it in the future.

My client was swapping from EMG's to a set of Fishman Fluence's along with a power bridge and a rechargeable battery pack installed on top of that. There was simply no way to fit it all in a standard LP cavity with long shaft pots.

Forstner bit is the go to. The problem was making sure it landed on the same general plane as the top carve as not to weaken the top too badly and to land in the proper spot in the cavity.
I made a jig that would sit flush on the top and put the guitar on a proper plane on my drill press. An indexing pin was clamped to the drill press table. The body was clamped to the drill press table as best I could and I had an assistant hold the rest of the guitars weight. Careful measurements were taken and the press depth stop employed. It was slightly nerve racking. The rest of the route to accommodate the pot lugs was dug out by hand with a small gouge.

Just as a note. First picture was how I received the guitar. The cavity was already semi butchered by a previous tech.

 

[NINFNM]

I realize this is a month old thread, but it caught my eye as I had to tackle this scenario a few months back. Maybe it will give someone an idea if they search it in the future.

My client was swapping from EMG's to a set of Fishman Fluence's along with a power bridge and a rechargeable battery pack installed on top of that. There was simply no way to fit it all in a standard LP cavity with long shaft pots.

Forstner bit is the go to. The problem was making sure it landed on the same general plane as the top carve as not to weaken the top too badly and to land in the proper spot in the cavity.
I made a jig that would sit flush on the top and put the guitar on a proper plane on my drill press. An indexing pin was clamped to the drill press table. The body was clamped to the drill press table as best I could and I had an assistant hold the rest of the guitars weight. Careful measurements were taken and the press depth stop employed. It was slightly nerve racking. The rest of the route to accommodate the pot lugs was dug out by hand with a small gouge.

Just as a note. First picture was how I received the guitar. The cavity was already semi butchered by a previous tech.

The work involved a heavy relic treatment to the back?

 

[lowatter]

I believe that the last 2 pics are examples from another LP that had the same treatment. I would never do that to a Gibson but to each their own I suppose.

 

[sdshirtman]

I believe that the last 2 pics are examples from another LP that had the same treatment. I would never do that to a Gibson but to each their own I suppose.

Correct. I had to do a few of them. Any other time I would have used long shafts but they simply wouldn't have left enough room for the battery pack to fit in the cavity.

The work involved a heavy relic treatment to the back?

The guitar came to me that way.