Secondary control cavity route..how do YOU do it?

Taller76

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Interested to see the different methods of making this route in one thread.
So how do you guys make these PITA routes? Ive seen a bunch of different jigs/methods, but thought it would be nice to try and put them in one thread...please discuss and post pics of your jigs.

Cheers
:cheers:
 

nuance97

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Taken from my build thread:

The control cavity route...This one confuses a lot of folks, but with the Bartlett plan it couldn't be easier. All the info you need to make your template is there! And BTW you'll need a huge router bit to preform this step. Mine was a 3/4" 1/2" shank bit that was over 4 inches long!!

It should end up looking something like this



Then clamp 'er up.


I lined mine up by eye...not the best idea. After I routed I had to reposition and reroute to get it exactly right.


 

Stephmon

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My approach isn't historically 'correct' but I don't mind avoiding the hazards of that route, with something simple. I roll the carved top on the drill press table and hold the bound edge down firmly. Then, I hit the pot positions with the Forstner.


 

Taller76

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I've read in various places that a 1" counterbore with a 3/8" pilot was used to make the "flats" where the pots sit so they would be 90º to the top...that appears to be how Fletch did his.

Hopefully he will chime in with details as the results are perfect...

Anyone have evidence of the tool marks the counterbore would have left on the floor of the cavity? e.g. a burst or goldtop with the pots removed.

Found one...not my photo, if its yours and you dont want it here let me know..


More:


 

nuance97

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I've read in various places that a 1" counterbore with a 3/8" pilot was used to make the "flats" where the pots sit so they would be 90º to the top...that appears to be how Fletch did his.

Hopefully he will chime in with details as the results are perfect...

Anyone have evidence of the tool marks the counterbore would have left on the floor of the cavity? e.g. a burst or goldtop with the pots removed.

Found one...not my photo, if its yours and you dont want it here let me know..
Yes I do believe that to be the case, and if absolute historical accuracy is the goal then I'd go the counterbore route.
 

RibbonCurl

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I don't quite understand ... Is the goal of the "secondary control route " to ...

1) Make "all" the pots sit 90° to the carved top? Or to make just a couple of pots sit more accurately (90°) to the carved top?

2) If I utilize the "Secondary Control Route" jig-angle stated in the Bartlett plans, how will that guarantee that the pots will be 90° to the carved top if mostly all carved tops are carved differentIy? I assume a specific jig-angle as stated in the plans is meant to be used for a specific carved top pattern?

Thank you
 

nuance97

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I don't quite understand ... Is the goal of the "secondary control route " to ...

1) Make "all" the pots sit 90° to the carved top? Or to make just a couple of pots sit more accurately (90°) to the carved top?

2) If I utilize the "Secondary Control Route" jig-angle stated in the Bartlett plans, how will that guarantee that the pots will be 90° to the carved top if mostly all carved tops are carved differentIy? I assume a specific jig-angle as stated in the plans is meant to be used for a specific carved top pattern?

Thank you
It’s probably not gonna guarantee a 100% 90 degree pot. It will be close enough, and for a lot of us replicating how Gibson did it is the goal.

The Bartlett Plans don’t have any carve contours or profiles unless they have done an update since I bought my most recent copy...so it’s hard to say what your carve will be specifically.
 

RibbonCurl

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It’s probably not gonna guarantee a 100% 90 degree pot. It will be close enough, and for a lot of us replicating how Gibson did it is the goal.

The Bartlett Plans don’t have any carve contours or profiles unless they have done an update since I bought my most recent copy...so it’s hard to say what your carve will be specifically.
Ok, but let's say I utilize the Bartlett-angle for the secondary-control-route and simultaneously utilize Scott's "Gold Standard Vintage Correct" carve-top patterns on his plans, would the results make the pots an acceptable or close-to 90° + - to the top??

This is my first build and trying to obtain all correct info before making jigs and such.

Thank you kindly
 

nuance97

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If you’re using Scott’s (aka my) plan you need to shoot for 7-7.5 degree wedges to angle the template up. The Bartlett plan was designed with a 5/8” thick top in mind. Mine and Scott’s was something closer to 9/16” thick. That 1/16” makes the angle slightly shallower
 

RibbonCurl

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If you’re using Scott’s (aka my) plan you need to shoot for 7-7.5 degree wedges to angle the template up. The Bartlett plan was designed with a 5/8” thick top in mind. Mine and Scott’s was something closer to 9/16” thick. That 1/16” makes the angle slightly shallower
Sorry, still trying to figure out who's who in this forum. Are you Daniel or Frank?

Ok, thus according to your plans, the 7-7.5 degree wedges for the template angle are to be used with a top measurement of around 9/16". Does that angle of 7-7.5 degrees take into account the thickness of the MDF or plywood jig-plate that the wedges are glued to? If so, what is the material and thickness of the jig-plate that the wedges are glued to?

Thank you very much
 

nuance97

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Sorry, still trying to figure out who's who in this forum. Are you Daniel or Frank?

Ok, thus according to your plans, the 7-7.5 degree wedges for the template angle are to be used with a top measurement of around 9/16". Does that angle of 7-7.5 degrees take into account the thickness of the MDF or plywood jig-plate that the wedges are glued to? If so, what is the material and thickness of the jig-plate that the wedges are glued to?

Thank you very much
I’m Daniel. The thickness of the template material is irrelevant in achieving the proper cut. I used 1/2” MDF with some little pine 2 x 4 scrap to make my jig
 

nuance97

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Sorry, still trying to figure out who's who in this forum. Are you Daniel or Frank?

Ok, thus according to your plans, the 7-7.5 degree wedges for the template angle are to be used with a top measurement of around 9/16". Does that angle of 7-7.5 degrees take into account the thickness of the MDF or plywood jig-plate that the wedges are glued to? If so, what is the material and thickness of the jig-plate that the wedges are glued to?

Thank you very much
33E8557B-F5FC-4BB6-AC1A-BB85A9A699AE.jpeg
 

nuance97

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Everything you need is in the drawing. Cut out the red area, and cut your wedges (in yellow) and put at blue locations. That’s all there is to it
2E4E540F-047C-4668-9BBE-61DC8996AB96.jpeg

Verify that the wedges are 7-7.5 degrees. I never checked. I just told Scott that’s what they should be. When I made mine I just used an adjustable angle gauge
 

RibbonCurl

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Everything you need is in the drawing. Cut out the red area, and cut your wedges (in yellow) and put at blue locations. That’s all there is to it
View attachment 493165
Verify that the wedges are 7-7.5 degrees. I never checked. I just told Scott that’s what they should be. When I made mine I just used an adjustable angle gauge
Daniel, just trying to understand please. How is the thickness of the MDF irrelevant? The thicker the MDF the more it increases the angle? In fact any thickness of the MDF will add degrees to the already 7-7.5 degree wedges? Thank you.
 

pshupe

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Daniel, just trying to understand please. How is the thickness of the MDF irrelevant? The thicker the MDF the more it increases the angle? In fact any thickness of the MDF will add degrees to the already 7-7.5 degree wedges? Thank you.
The angle is the important part. The thickness is irrelevant. The thickness does not change the angle just offsets the distance so you would need a longer bit.

Regards Peter.

PS - quick cad dwg - the thickness of the template itself doesn't make any difference. I have 3/8" shown. It could be 1/2" or 3/4" it would not change the angle.

Capture.JPG
 
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nuance97

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Daniel, just trying to understand please. How is the thickness of the MDF irrelevant? The thicker the MDF the more it increases the angle? In fact any thickness of the MDF will add degrees to the already 7-7.5 degree wedges? Thank you.
The wedge you cut is literally the only thing that affects the angle. I’ll take a pic of the underside my template for you
 

nuance97

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The angle is the important part. The thickness is irrelevant. The thickness does not change the angle just offsets the distance so you would need a longer bit.

Regards Peter.
Yes ^^
 


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