50s LP control cavity angle

[gtrmaker]

Excellent photos Magnus! This certainly helps us to envision the cavity angles better.

[alk-3]

Okay, it just now dawned on me what the v is all about. I feel like an idiot for not realizng until now.
When the guitar is routed, it is first done exactly paralell to the back, then the guitar is put into a jig that angles it, which also produces the nibble marks. When the first rout and the second rout converge there is an angle change. I am away from the shop until Sunday, but I will take some photos of this being done, and the resulting v for you guys.
The v is infact there, as a byproduct of the two routs.
This is how I have always done it, and I use a pin router with fixtures.
I'm sorry it took me this long to realize what you were talking about, but his v is in fact there.

[gtrmaker]

Originally Posted by alk-3

Okay, it just now dawned on me what the v is all about. I feel like an idiot for not realizng until now.
When the guitar is routed, it is first done exactly paralell to the back, then the guitar is put into a jig that angles it, which also produces the nibble marks. When the first rout and the second rout converge there is an angle change. I am away from the shop until Sunday, but I will take some photos of this being done, and the resulting v for you guys.
The v is infact there, as a byproduct of the two routs.
This is how I have always done it, and I use a pin router with fixtures.
I'm sorry it took me this long to realize what you were talking about, but his v is in fact there.

I follow you, but in order to put the "V" that the experts are referring to with the intersection point being between the volume and tone pots then I don't think it is the one you're talking about which I believe is the transition between the surface parallel to the back and the angled route. This transition falls beyond all of the pots.

[alk-3]

No, I think it is exactly what they're talking about. The drawing that magnus made that I posted earlier shows the point of the v right on one of the pots, in actual practice this point of the v would be bisecting the cavity almost perfectly. I will post photos of this as soon as I gt home.
If you go to the burst registry you can see they did very somewhat depending on the depth the pin router was set to, but the usually land right about th middle of the cavity.

[landsharkey]

That's just the point. The rout doesn't even go throu the mahogany all the way, let alone have enough room for a bearing. I can't add a link from my cell phone, but if you go to my website I have a photo of the control cavity under complete bodies that shows this.

Ok, thanks I get it now - sorry for the confusion. I found the control cavity photo.

[alk-3]

Originally Posted by landsharkey

Ok, thanks I get it now - sorry for the confusion. I found the control cavity photo.

Right, although that photo does not demonstrate the v issue because the cuts paralell to the guitars back are not quite deep enough.
But, as mentioned I will take some other shots to demonstrate it better

[Fletch]

Originally Posted by gtrmaker

"The portion of the maple top that the potentiometers are mounted should be a shallow 'V' shape, with the point located between the volume and tone controls." He then goes on to say that "The pots should be angled away from each other but at a 90 degree angle to the curved top. If the posts are parallel to each other, the cavity is flat and the guitar is not original."

You're thinking too much...

When I read this, I take it as the two surfaces that make up the inverted "V" are the flat surface that is parallel to the flat bottom of the guitar, and the angled surface that is cut into the flat surface for the innermost pots to sit on.

The line between the volume and tone pots sentence is being taken too literally in this statement as well I believe. Where the line REALLY is is between the neck pickup volume/tone pots and the bridge pickup volume/tone pots, I think that is what he meant... it's just the way it reads that makes it seem like that. I think he meant volume and tone pots collectively, not specifically. Sometimes writers and editors in newspapers and magazines take liberty with text to make it more fluent to the reader, and sometimes things get lost in translation...

This will make the pots sit at a 90° angle from the top, and make them angled away from each other- when viewed from the bottom. Basically there are only two cuts/surfaces/planes/whatever you want to call them in the cavity floor, not three.

fletch

[gtrmaker]

alk-3 and Fletch, I agree with what you are saying. I went back and took at look at the many cavity photos I have saved and agree with the transition point being not literally between the volume and tone pots. That's why it's great to talk these things through. Alk-3, I look forward to your photos.

[alk-3]

Originally Posted by Fletch

You're thinking too much...

When I read this, I take it as the two surfaces that make up the inverted "V" are the flat surface that is parallel to the flat bottom of the guitar, and the angled surface that is cut into the flat surface for the innermost pots to sit on.

The line between the volume and tone pots sentence is being taken too literally in this statement as well I believe. Where the line REALLY is is between the neck pickup volume/tone pots and the bridge pickup volume/tone pots, I think that is what he meant... it's just the way it reads that makes it seem like that. I think he meant volume and tone pots collectively, not specifically. Sometimes writers and editors in newspapers and magazines take liberty with text to make it more fluent to the reader, and sometimes things get lost in translation...

This will make the pots sit at a 90° angle from the top, and make them angled away from each other- when viewed from the bottom. Basically there are only two cuts/surfaces/planes/whatever you want to call them in the cavity floor, not three.

fletch

Bingo. Nicely said fletch.
The trouble I had earlier trying to Invision this was the v not being inverted. Doh.

[theodoropoulos]

hallo!
my question is this:the axis of the pots are vertical to the chambered surface.so if we drill a hole for the pot how can we manage the hole to be vertical to the surface?if we use a vertical to the table drill ,the axis of the pot and the axis of the drill are not parrallel.Simply,how do you drill the pots?with angle?

[GooCart]

I've understood that the holes are drilled parallel to the table and reamed up to right size and angle.

[theodoropoulos]

with which tool do we drill with angle ?

[nuance97]

Originally Posted by theodoropoulos

hallo!
my question is this:the axis of the pots are vertical to the chambered surface.so if we drill a hole for the pot how can we manage the hole to be vertical to the surface?if we use a vertical to the table drill ,the axis of the pot and the axis of the drill are not parrallel.Simply,how do you drill the pots?with angle?

The answer to your question is right here...

Originally Posted by alk-3

...the pot holes were drilled stright down on a press and then reamed by hand to angle them....

[GooCart]

The angle and final hole size isn't drilled. I'm talking about one of these, a reamer.

[theodoropoulos]

in my opinion it's very difficult to achieve the same angle of the pot and the top surface with a reamer.
i would gauge the anlgle of the surface where the pot will be put and with a jig drill/route a hole with the same angle.i would also route the area around the hole just to put the whole pot vertical to the surface .Am i correct?

[gtrmaker]

You could do it that way and it would be fine, but it is not how the vintage guitars were done or how most clone builders do it. It's all about trying to make the best clone out there since most of us can't afford the real thing.

[nuance97]

You guys really lost me with all of this inverted v business.

I really liked the way the control cavity came out on Ex-nihilo's 2nd build, and when I get around to building a Lester I intend on replicating that method. Is it dead on exactly identical to a '59? I don't know. Nor do I care. I know it was functional, and the jig looks simple to make and use so that is why I would like to know a little more about it.

alk-3, I don't know if you even have the thing any more, but if you do please take a look at my crude illistration below of the jig that you and ex used (I don't have all of this fancy cad stuff so a pencil and paper had to do), and if you would be so kind, answer a simple question.

If you took the jig, and mark a line (dotted line in the drawing) square to the straight edge of the jig then measure the angle that is created between the jig along that line and the flat surface of the guitar back what would that angle be?

Would that be 8 degrees?

[gtrmaker]

The angles are interesting on Magnus's 53GT which he says has a low top arch height. Using a CAD program I get angles approximating 3 and 5.25 degrees :



and:



If you want to try this at home make sure you use the extra precision King Size Sharpie!

It would be great to see similar phots of a late 50's LP for comparison.

[gtrmaker]

Originally Posted by nuance97

If you took the jig, and mark a line (dotted line in the drawing) square to the straight edge of the jig then measure the angle that is created between the jig along that line and the flat surface of the guitar back what would that angle be? Would that be 8 degrees?

No, you're way off base. If you look at the angled routing jig that alk-3 shows in his jig photo below, the wedges shown under the main router board are at an 8 degree taper. It has nothing to do with the angle relative to the neck/body centerline.



Also if you look at the bottom photo I posted above, what shows as a 5.21 degree angle would be 8 degrees. This is the angle routed into the bottom of the control cavity relative to the flat back of the guitar.

[alk-3]

Originally Posted by nuance97

You guys really lost me with all of this inverted v business.

I really liked the way the control cavity came out on Ex-nihilo's 2nd build, and when I get around to building a Lester I intend on replicating that method. Is it dead on exactly identical to a '59? I don't know. Nor do I care. I know it was functional, and the jig looks simple to make and use so that is why I would like to know a little more about it.

alk-3, I don't know if you even have the thing any more, but if you do please take a look at my crude illistration below of the jig that you and ex used (I don't have all of this fancy cad stuff so a pencil and paper had to do), and if you would be so kind, answer a simple question.

If you took the jig, and mark a line (dotted line in the drawing) square to the straight edge of the jig then measure the angle that is created between the jig along that line and the flat surface of the guitar back what would that angle be?

Would that be 8 degrees?

The jig we used on Scotts guitar was a bit crude, and I have not used it in a long while but I will have a look for it. As mentioned I use an overarm pin router, so I may have to dig a bit for the jig, but I will certainly provide you with the required angle.
By the way, all of this will be on the plans magnus and I are making.

[nuance97]

Originally Posted by gtrmaker

No, you're way off base. If you look at the angled routing jig that alk-3 shows in his jig photo below, the wedges shown under the main router board are at an 8 degree taper. It has nothing to do with the angle relative to the neck/body centerline.

Also if you look at the bottom photo I posted above, what shows as a 5.21 degree angle would be 8 degrees. This is the angle routed into the bottom of the control cavity relative to the flat back of the guitar.

I'm not concerned with the angle relitave to the center line. The compund angle that the jig in the photo creates is not based off of the center line. It is based off the straight edge of the jig that runs from mid horn to a point a few inches to the right of the center line. That is why I'm only interested in the one angle.

[bfcg]

I use an adjustable angle jig and I adjust it until I match the angle of the top carve and go deep enough to leave the most wood possible while still allowing for short shaft pots.

[gtrmaker]

Originally Posted by nuance97

I'm not concerned with the angle relitave to the center line. The compund angle that the jig in the photo creates is not based off of the center line. It is based off the straight edge of the jig that runs from mid horn to a point a few inches to the right of the center line. That is why I'm only interested in the one angle.

Since alk-3 is no longer using this jig maybe he'll sell it to you. Or maybe you could work out a rental deal!

[nuance97]

Originally Posted by gtrmaker

Since alk-3 is no longer using this jig maybe he'll sell it to you. Or maybe you could work out a rental deal!

Is this comment meant to sound snide?

I just think that particular jig is an elegant solution to a pretty complex operation, and you can use a handheld router which is a must for me since I don't have a pin router.

[nuance97]

Originally Posted by bfcg

I use an adjustable angle jig and I adjust it until I match the angle of the top carve and go deep enough to leave the most wood possible while still allowing for short shaft pots.

I'd like to see yours.

[gtrmaker]

Originally Posted by nuance97

Is this comment meant to sound snide?

I just think that particular jig is an elegant solution to a pretty complex operation, and you can use a handheld router which is a must for me since I don't have a pin router.

Not at all. I just figured since you would have to build one like it and he's not using it that this could work out good for both of you. Since he may not want to sell it he may be willing to rent it when you eventually need it. There's nothing wrong with this jig in my opinion.

[gtrmaker]

Originally Posted by bfcg

I use an adjustable angle jig and I adjust it until I match the angle of the top carve and go deep enough to leave the most wood possible while still allowing for short shaft pots.

ditto.

[nuance97]

Originally Posted by gtrmaker

Not at all. I just figured since you would have to build one like it and he's not using it that this could work out good for both of you. Since he may not want to sell it he may be willing to rent it when you eventually need it. There's nothing wrong with this jig in my opinion.

Oh, okay. It's hard to tell sometimes if some one is being condecending or what when you're just reading words on a screen.

[Metamatic]

I have nothing to add or share on this subject. But I must say that I love this constructive discussion. Very interesting, indeed.

Last week I drilled the pot holes on my upcoming GT and I searched the forums how the LP was drilled. Found nothing so I just drilled some holes a bit smaller than the plans in a 90 degree angle. Now I know how it should be and I thank this thread for that.

[nuance97]

Originally Posted by Metamatic

...I love this constructive discussion. Very interesting, indeed.

+1