Template Routing Trouble ! HELP!!!!! - Woodworking Talk

tiorunder · 03-15-2008, 10:14 PM

Hey!

My name is John and I am a newbie to the forum. Having a BIG problem routing with a template. Here's what I'm doin':

I am using a template to rout a neck cavity into a guitar body. The guitar neck itself fits good and tight into the template but after I do the router work on the body I don't get the same tight fit when I install the neck into the body. I thought that there might be something wrong with the router bit and replaced it with a brand new one only to get the exact same results. I am about to go out of my mind! Please help!
Thanx in advance, Tiorunda John.

mmwood_1 · 03-16-2008, 07:47 AM

John,
Not clear just how you are going about it. Are you using an exact size template, and a bit with a bearing which rides against the template then cuts to the same size as the template? That's what it sounds like to me. If that's the case, then the obvious problem is that your bit is NOT cutting to the exact size as the template.

I guess the pertinent question is, did you already rout the cavity into the guitar body? Or just into a test piece? If it's just into a test piece, you are still ok.

Some possible remedies:
-You could get the bit ground down a little to reduce the diameter of the cutter. Regular sharpening accomplishes this. You did not indicate just HOW loose the fit is, but I'm assuming it's just a little.
-you could make a new template which is just a hair smaller, that way when you rout out the cavity in the guitar body, it should fit the neck just right.
-you could tape the edges of the template which the bearing rides against in order to reduce the size by just a hair. That MIGHT work.

On the other hand, if you've already routed it into the guitar body, and it fits loosely, it's a problem. I understand the construction of a guitar, but never having built them, I don't know how it would affect the instrument if you fudged that joint. In other applications, this problem could be remedied by cutting paper thin strips of wood and inserting them, with glue, as shims between the joints to take up the slack of the loose fit. I don't know if that would be appropriate in this application. It's certainly not ideal. I think the luthiers on this forum will have to help you, if that's the situation. Good luck.

tiorunder · 03-16-2008, 10:24 AM

Mark, thanks for the fast reply. Your first paragraph describes exactly how I am going about it. And yes I am practicing on scrap wood. After having slept on it I think I am going to make a new template that is a touch smaller as per your advice. I did try taping the template but with limited success. As for sharpening the bit to reduce its diameter - I am willing to try this also. How does one sharpen a double fluted router bit without taking more material off of one flute than the other?

Thanks again - John

pianoman · 03-16-2008, 11:04 AM

You might check the bit in the router with a dial indicater. Also... what is the template made of? What kind of router are you using? Rick

mmwood_1 · 03-16-2008, 08:06 PM

John,
I think you'll have success if you make the smaller template, and just use the bit as is. As for sharpening, I don't try. I send all of my router bits and saw blades to a machine shop for sharpening. I pay from $4-$6 per router bit, and they're done right. Screw up, and you could lose a $20 bit.

But I'm relieved, for your sake, that you did a test first. See if you can measure the difference in size between the template and the practice cut. Try making the new template either that much smaller, or even just a hair tighter. If it's just a hair tight, a little minute sanding can relieve the tightness. Either on the template, or on the neck end of the joint. I'm assuming this is a wedge shape, is that right?

KC7CN · 03-16-2008, 10:30 PM

I'm curious about the bit you are using. Can you describe it for us? Size, manufacture, how long have you been using it, etc. Another question comes to mind - does the bearing appear to be in good condition? It would be interesting to test your template with another bit.

-Don

tiorunder · 03-16-2008, 11:09 PM

I would like to thank everyone for their input. This is a great forum indeed.

The router bits (2) are new, both Amana. Double fluted template cutting plunge bits that have a bearing on top (obviously). The diameter of both cutter and bearing measure .500 with my digital caliper. The guitar is a copy of a Fender Telecaster and has a bolt-on neck. The neck sits flat into the body cavity which is 3" long, .625 deep and 2 and 3/16 at the heel end (bottom end). From here it slightly tapers toward the top of the body. After much trial and error and deep thought and all of your help, I think my biggest problem is with the material I am using for the template (MDF). I have successfully made the template smaller and now have a snug fit to my liking. Tomorrow I will make a Master template in a piece of red oak board that I have lying around in my shop. I would like to thank you all again for your input. John from Tiorunda.