Mortise-Tenon Jig Improvements

[DJ Parker]

Well, I'm at it again,,,re-working an already decent jig to make it better. I'm sure many of you use a variation of this mortise/tenon jig made famous by Robert O'Brien. I believe it is a good design and I see that even he has improved his over the years especially by adding a centering guide which I too have implemented.

Although not quite complete, I have been replacing parts of the overall jig with Plexi. I like being able to see through the jig as it helps me align the body and since I have access to the CNC, recreating the parts with plexi is fairly easy (lucky me). Lining everything up is so key in building and this approach really gives me a comfort.

Notice the cradle strap, which is simply a guitar strap. I want to make a ratchet assembly so that it can be tightened easily. The last thing you want is the body slipping out !

Thanks for looking and please add your 2 cents.
Regards,

[Bob Shanklin]

I like the improvements, especially the strap. Great idea.

Bob

[Randolph Rhett]

I've been thinking of adding an O'Brien style jig to my shop. Are there detailed plans somewhere? I was under the impression that O'Brien sold them, but can't find it on his website. I know LMI is selling it as an assemble it yourself kit, and for $200 it probably isn't worth my time making one. But I am loathe to spend that kind on money on some MDF and plexi.

[DJ Parker]

Well Randolph,

I have around $50 in this jig with materials plus I gave my friend a few bucks for the CNC use. The store-bought jig looks of decent quality but you're right, it is MDF. I used good plywood that I had. I don't know of any plans but I believe there are some. I do know that O'Brien has a YouTube video of him building one from scratch and that is where I started. He mentions some of the sizes for pieces but it really is a flexible jig and can be made pretty much to your specs.

Thank you,

and Thank you as well Bob,

I appreciate your comment. I must admit though, the strap wasn't my idea. I saw it or something like it used somewhere else and just adapted it.

Regards

[Steven Smith]

I've been thinking of adding an O'Brien style jig to my shop. Are there detailed plans somewhere? I was under the impression that O'Brien sold them, but can't find it on his website. I know LMI is selling it as an assemble it yourself kit, and for $200 it probably isn't worth my time making one. But I am loathe to spend that kind on money on some MDF and plexi.

Ask Robbie. He's good about answering inquiries.

[Randolph Rhett]

I contacted Robbie and he sold me some plans. Nice to have actual plans, even if the jig seems obvious. Saves me from making dumb mistakes.

[Steve Sawyer]

DJ - for that strap, go to one of the big-box stores and pick up a light set of load-binder straps. They come in widths as narrow as 1".

Get out your dremel with a cut-off wheel (or an angle grinder with a cut-off), and cut the big "S" hook off the end of long strap (they're hard as hell, so a hack saw might be tough going). Cut or drill out the pin on the ratcheting mechanism where the short strap and S-hook attaches, discard the short strap and S-hook, replace that pin with a bolt and a nylock nut, running the bolt through the loop on the long strap that you freed up when you took off the "S" hook. You'll end up with a ratcheting strap perfect for this purpose.

See the pic which hopefully makes all of this clear.

[DJ Parker]

Thank you very much Steve. Great idea!

[Steve Sawyer]

Thank you very much Steve. Great idea!

I came into some 8020 aluminum extrusions, and am in the process of cobbling together my version of that gollywog StewMac neck jig, and needed some of these to make that work.

[Randolph Rhett]

I know this is an old thread, but I'm just finishing up making one of these. On the guitar body side, obviously it has to be placed right at the edge of the table because the guitar hangs below the bottom edge. So how do I clamp it to the table?