[rficalora]

It's been a few years since I've been on this board; hoping someone can help with a how to technique...

I'm building an electric guitar with my son. The way it's made, there is a large pocket routed out of the back that houses the tone and volume switches. There is a cover that goes on the back of the guitar to cover that hole. We want to make that cover fit flush to the back so I need to inlay it.

I need to somehow use the cover to make a template so my son can route the recess.

I have several flush trim bits ( both top and bottom bearing versions). I also have a few spiral cut bits in 1/16, 1/8, and 1/4". I don't have an inlay collet but, I do have a rabit bit set with 6 or 7 bearings.

Before I go out and buy a collet set, any ideas how to do it without them?

 

[JMartel]

One easy way to do it, is to use double side tape to stick the cover down, and then use an exacto knife to trace around the cover. Make sure you get good deep lines around so you can easily see it. Make multiple passes. After you think you have it deep enough, take the cover off and you will see your outline. If it's a dark wood, I would take some chalk dust and rub it into the knife marks to help them stand out. Then, you would set the depth of the router bit to the thickness of the cover, and rout away. I'm not sure what your cover is shaped like, but I would use the 1/8" or 1/4", unless there is a corner with a radius smaller than that.

When you rout out the excess, watch very closely next to the router bit. You will see some fuzz. When you approach the cut line, the fuzz will be there, and then all of a sudden disappear. When it disappears, you know you are at the line. I would use a lot of light so you can see what you are doing easily.

That's how I did these cutting boards for a coworker:

 

[Quickstep]

JMartel's way is probably the easiest long run. Practice on some scrap first, but as JMartel says, you'll see that fuzz as you get to the cut line, but there's value in experiencing that on scrap before trying it on the real deal. A pair of high magnification glasses helps too.

You could make a template in a similar manner. Trace the outline of the cover on piece of MDF or good plywood and cut out the shape with a bandsaw or jigsaw. Then use a drum sander to make smooth curves and to get the template to the exact right size. This will make a template you can clamp to the back of the guitar and follow with a flush cutting bit with a top bearing. This will give you a repeatable way to cut the recess if you're making multiples, but for just one, JMartel's way will be quicker and easier.

 

[Wema826]

If the pocket that houses the electronics is already routed / bored out. why cant you just use your rabet bits and the correct bearing to make the recess for the cover? just go to the depth of the cover! IF you do not have the correct size bearing, you may need to get one.

I do not know whai kind of free hand router experience you have. but. If you are inexperienced or too nervious about doing the the way Jmartel suggests getting the correct size bearing with the correct depth bit would be the best option. In my opinion.

 

[rficalora]

Thanks guys. I'm comfortable enough with a router to freehand the cut, but I've been trying to let my son do most of the work. I've been making templates so he could do the machining on the guitar. He's 14 and we are pretty far along, so I don't think I want to take the risk letting him do it freehand.

Also, the switch pocket is 4 overlapping forstner holes and doesn't match the shape of the cover (a plastic piece we bought) so just using a rabbit bit won't work.

Since I won't have time to work on it again till the weekend, I went ahead and ordered the collars for my router. I think I could have figured out a way to do it with bits I have, but using the collars will be faster.

For anyone interested, here are a few pics showing what we've done so far...

 

[Quickstep]

Wow! Very Cool!

I'm curious how you cut the contours in the top and how you smoothed them.

 

[rficalora]

To "carve" the top, the first thing I did was visit our local Guitar Center. They let me use a carved top guitar to figure out the contours. I used a straight edge and caliper to figure out countour lines representing 1/16" drops.

I then transferred the contour "map" to some MDF. My son routed the 1st layer - the deepest (outer) layer. Then he cut the template along the next contour line and routed the next layer 1/16" less deep and repeated for each consecutive layer. We did end up having to double the thickness of the last few sections of the template to keep the router bit bearing in contact. If this doesn't make sense, let me know and I can shoot a pic of the template.

To smooth it, we used a mix of a 1/4 sheet sander, a "mouse" sander, and hand sanding with short pieces of various sizes of PVC pipe and cardboard tubing. He started with 80 grit and worked up to 120 so far. The shape is pretty good, but he has some more work to do to refine it. I think if I were doing it I'd use an angle grinder with a sanding disk to get most of the work done, but thought that was too aggressive for my son's 1st attempt.

If it warms up a little, we should be able to get the shaping finished and maybe get the finishing started this weekend. Plan is for a black/black cherry and red stain/dye technique to show off the figure in the wood.

 

[RogerC]

I have a side business building custom electric guitars, and I do it by making an outside template of the cover out of 3/4" mdf. Then I attach the mdf to the back with double-sided tape, and use a top-bearing bit lowered into the work at the depth of the cover.

 

[rficalora]

Right, but what's your process for making that outside template? Without an inlay collar, that's what I was struggling with. May be a moot point as I have a collar on order, but if you have a creative way that doesn't require it, please share in case the one I ordered doesn't come in by Saturday.

 

[frankp]

You can make the outside template by tracing the cover and then cutting with a scroll saw, router, coping saw, or whatever else suits your needs. I did ours freehand but didn't let my (then) 14 year old do it either. She wasn't too interested in that part anyway.

 

[RogerC]

I typically drill the corners with an appropriately-sized forstner bit, then set up a straight edge to follow with a router for the straight sides.