How do you make your control cavity cover?

dinkyguitar

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Hi All,

I'm working on routing the control cavity on my super strat model.

I have the template for the control cavity, then the template to route the channel so the control cavity sits flush on the body.

But, is there a way to use the templates I already have to route out a control cavity cover? Using either a top bearing or bottom bearing router bit?

I've been brain storming this idea but don't know if it's possible.

Is there another way? or do I just make a control cavity cover and size it to fit.

dinky,
 

buyusfear

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Easiest way I've found to to trace the cover shape onto a piece of paper, spray adhere that to some mdf, band saw out as close to the line as possible and belt sand to the line testing the fit.
Then just double stick your pickguard material to that shape, stick that to a sacrificial board and flush trim route the cover.
 

pshupe

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Probably the easiest way is to trace out from your control cavity cover recess template and then make that the template for the cover. You could try and offset in a little bit, like 1/64" or so, or just use a bit with a bearing a little bit smaller than the bit. I can't think of an easy way to cut a positive that is close in size to the negative, if you know what I mean? You may be able to cut your cavity cover recess using the cavity template.

Good luck.

Cheers Peter.
 

dinkyguitar

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That's what I thought.

pshupe,

Had the same thought using a smaller bear on router bit, since I have an assortment.

thanks guys,
 

cmjohnson

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You do it with two bits with the appropriate guides and bearings, and here's the explanation:


In one sentence, make a template 1 inch larger than the original with a suitable pattern bit and bearing combination, then rout with a 1.5" guide and a 1/2" cutter.



Let's say you're copying a circular cavity cover that's 3 inches in diameter.

If you were to copy this with a regular flush cutting template bit, let's say a 1/2" diameter bit with a 1/2" diameter bearing, the first thing you do is use this to make an OUTSIDE template, that is, the template is a piece with a big hole in the middle of it. In this case the hole will be 4 inches in diameter because obviously the template bit will cut a half inch on each side of the original piece.

Now you will use your new template with a guide/bearing and cutter combination that
will give you a SMALLER piece than the template.

If you were to use a 1.5 inch guide and a 1/2 inch bit, what you end up with is pieces that are the same size as your original.

Be sure to mark your new template with the required bit and guide/bearing sizes so you don't forget in the future. I recommend engraving that information on them with a dremel and a small pointed bit.


By adjusting guide and bearing diameters, you can use this method to make smaller or larger covers having the same base shape,
if you need to.
 

TheHarleyMan2

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If the cavity is already there but no cover, I always just use a piece of paper and put over the cavity and use a pencil to shade in the area where the edges of the cavity is, then I have an outline of the cavity on paper.

Then I go from there and make a cover for it.
 

Bill Hicklin

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You do it with two bits with the appropriate guides and bearings, and here's the explanation:


In one sentence, make a template 1 inch larger than the original with a suitable pattern bit and bearing combination, then rout with a 1.5" guide and a 1/2" cutter.



Let's say you're copying a circular cavity cover that's 3 inches in diameter.

If you were to copy this with a regular flush cutting template bit, let's say a 1/2" diameter bit with a 1/2" diameter bearing, the first thing you do is use this to make an OUTSIDE template, that is, the template is a piece with a big hole in the middle of it. In this case the hole will be 4 inches in diameter because obviously the template bit will cut a half inch on each side of the original piece.

Now you will use your new template with a guide/bearing and cutter combination that
will give you a SMALLER piece than the template.

If you were to use a 1.5 inch guide and a 1/2 inch bit, what you end up with is pieces that are the same size as your original.

Be sure to mark your new template with the required bit and guide/bearing sizes so you don't forget in the future. I recommend engraving that information on them with a dremel and a small pointed bit.


By adjusting guide and bearing diameters, you can use this method to make smaller or larger covers having the same base shape,
if you need to.


What's wrong with just using a flush-bearing bit?
 

cmjohnson

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Because while you can use a flush bearing bit to make one direct copy, there are times when you want to be able to make not just a copy but make a template to make many copies, and using the method I described also has the very large advantage of being a means to create a fitted cavity template using its cover as the master.

If you've ever had to try to make a custom shaped cavity cover, that's easy. But making a matching recess in the body that cavity fits into, that's a bit trickier but the method I describe is IDEAL for that job.

I actually should have specified that from the start. My fault I didn't make that clear.
 

Bill Hicklin

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Okay, got it. Makes complete sense now.

All I ever make is one-offs, so repeatability doesn't really enter in
 

cmjohnson

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If I do a singlecut with a 2V2T control layout, I use the same layout and the same cavity pattern every time. So yes, I have made templates and fixtures for making covers and cavities that match. If nothing else I'd like to use standard cavity types
on custom guitars whenver possible, so I don't have to invent another wheel every time a guitar build starts.
 

geoffstgermaine

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I use a kit from Lee Valley like the one D'tar posted to do my work like this. As cmjohnson has said, this probably works best in the situation you're in.

As a suggestion, I have had all of my cavity and cover templates (and pretty much all other templates I require) laser cut by a local engraving place in various thicknesses of clear acrylic sheet. I sent out a quote request on a whim and when I got back the very low cost I did up a lot of work for them to cut. It's worth considering if you're able to do the drawings up in anything like Illustrator or a CAD program.
 

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