Todd Stock's and Bob Gleason's router jigs for mortise and tenon and dovetail neck joints [Pictures] - created 08-31-2007

Stock, Todd - 09/07/2007.06:44:10

This one works well - close to the SM directions, but a little stiffer and uses a 1/2" baltic birch caul to keep the body in place.

Front

Back. The two full-length ply pieces make the jig very stiff.

All in inches.

Cheap Borg hardwood ply works for everything but the top and the 3 wide by 20 long baltic birch caul.

20 wide x 24 tall for the main component; the base is 8" wide by 20" long; verticals are 4 wide x 24 tall, and the top is 16 x 16 to take the SM templates.

FWIW, these template vary from less than .300 thickness to more than .375, so have the templates on hand before routing the top - level or slightly proud of top is a good idea.

Cheers...

Todd

Todd, What keeps the guitar body from shifting side to side in your holding jig? Also are you mounting the neck in the same jig? I currently clamp my jigs onto the body and neck for cutting dovetails, but it's a lousy system!Yours look simple and cool. Thanks for posting the photos.-Bob

I use a separate Woolson-style neck jig for cutting the tenon or dovetail, and for doing the initial shaping on the heel.

On the mortise/dovetail socket jig, the 1/4" cork pads shim the body so the neck area is parallel with the top, and the caul flexes enough to firmly clamp the body without any side-to-side movement. Thought about clamping a block to each side of the guitar to prevent movement, but turned out to be overkill - the caul alone is fine, given that the cork compresses a little.

One note on the templates used for these jigs - check the width of the tenon and of the mortise if you have purchased ready-made templates...mine were not even close to .750 as shown in the specs - the mortise template was nearly 1/16" wider than the tenon...very sloppy fit requiring shims in the neck mortise. If the dimensions are not in agreement, return the templates and fabricate a set or buy from another vendor.

FWIW, Luthiers Tools mortise and tenon and dovetail templates are CNC cut aluminum, and are very well machined. Also less expensive than the less durable acrylic or ply templates offered by other suppliers. No interest - just an incredible company making very useful jigs and fixtures for builders.

Todd, So you inspired me to do something I've been wanting to do for 25 years! I've lived with multiple variations of dovetail jigs for all that time, swearing that I'd never make another instrument until I made a really good jig. Of course, when it came to neck joint time it was always "Just one more time, then I'll fix it." I wanted a jig that would do both the neck and body of any size instrument from ukes to guitars. Many T-nuts,lots of wasted plywood cuts, a day and a halfs work, and this is what I came up with. Unfortunately I don't visualize well, so I have to make a piece several times over to get it right. I did one guitar joint with it yesteray. Came out better than any I've ever done. I'll attach the photos in several posts. The thing with all the holes that you see through the plexiglas is the top of my downdraft sanding table which is built as an outfeed table for my tablesaw. Makes the photos a little confusing, but the dovetail jig is actually a foot or so above the table. The holding brace across the back of the guitar rides on cork just over the sides and does not press on the back. Ther plexiglas templates slide in the holder so any depth of guitar can be done. For smaller instruments I'll make a second set of templates.

And here is the mess that all this replaces!

Looks great. Are the plexiglass templates bought or did you make them? If you made them, how did you cut them accurately?Like Mark said,big pictures would be great.Thanks.

Just a note to follow up on the neck template caution I posted earlier in the thread. I emailed SM and got the straight scoop WRT the apparent mismatch between mortise and tenon widths on their template set.

Stew Mac sizes their neck templates such that there is an intentional 1/16" difference in width between the tenon and the mortise. This is to provide the ability to shift the neck for best alignment with the centerline. Same deal on their kit necks and neck blocks.

I stand corrected - the difference in width is an intentional feature, rather than a manufacturing issue or flaw.

Bob,

One quick question on your jig. I understand the two sets of lateral sliding guides to hold the work piece steady left to right and the bar accross the back to hold the whole thing in place. However, there seems to be a large plate at the bottom with slots cut into it to allow it to be positioned up or down. What does that do? In the pictures it doesn't seem to be doing anything.

Thanks,

To make the guitar templates for this jig, I used a router pattern bit to copy a set of templates of unknown origin. They were given to me a few years ago. The ability to slide the templates in my jig lets me do that adjustment that Todd related to. 1/16" is too close for me. I need a little more working room to get everything right so I leave the neck about 1/8" proud of the body and hand work it from there. Maybe I can get closer with this new jig.As far as making dovetail templates goes, I've made a lot of them in different sizes though and it is not difficult. I just have to carefully draw a long triangle on wood. I cut the wood template to size using a router run along wood guide strips. I don't think you can make good clean templates on the bandsaw. I then use the wood template to cut the final plexiglas one. One tip is to make sure you use the final template to make a spare by using a flush trim bit or pattern bit. You will most certainly hit that first one with a router at some point, and, with the spare you'll be back in business. That board at the bottom of my jig has a piece of cork on the top edge and it slides up against the body to keep it from slipping down.