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Okay, things have ground to halt in the workshop while I work out exactly how to use the Stewmac mortise and tenon templates.

Ive made up the jig as per Stewmac instruction sets and have their angled dovetail bit and the guide bearing.

The Stewmac instructions are vague and the jig is very fiddly with not much room forerror. I guess what Im after is instruction and tips from people who are using the same set up. Some pics of the bit/jig in action or direction to a website with same would be greatly appreciated.

Many thanks in advance.

s-m's shop tips video of a few years ago had a good segment on the use of the templates and the jig.

i have the video somewhere but even if i duped it, it wouldn't do you any good because it is ntsc, not pal.

Thanks Michael,

Ive just been out for a long boozey lunch with some fellow Geologists and like a true luthier I spent most of lunch thinking about Mortise and tenon joints. In between the copious amounts of food and alcohol I managed to nut out a plan. Ive locked a piece of spare Honduras mahogany into the SM jig and have set the template for a cut outside the line of the desired neck tenon. Ill rough out the wood with a straight cutter and then go in with the dovetail cutter. Once thats done Ill move the template up a fraction at a time untill the dovetail cut is in the right place. Ill then note the template and cutter settings and use these as settings for the real thing.

I guess its the age old plan of action whenever youre not sure about what youre doing....do a test run on a pice of scrap wood.

Sounds like your talking about a dovetail joint, not a mortise and tenon (M&T).

[QUOTE=BarryDaniels] Sounds like your talking about a dovetail joint, not a mortise and tenon (M&T).[/QUOTE]

Yes youre absolutely right....making a dovetail joint. Thanks for the correction Barry.

Im making some progress with the problem. Have installed a mahogany neck offcut in the jig and rough routed to dovetail depth with a straight cutter. With the template adjusted to cut outside the final line of the neck dovetail Ill next make progressive cuts with the dovetail cutter untill Im on the line and note template and cutter settings. Actually not as hard as I thiught it would be..just fiddly like alot of jigs but once its set up using it is alot easier.

Getting there....

Ive managed to route up a half decent dovetail set on scrap mahogany. The fit wasnt perfect due to the bit slipping in the collet at one stage but I managed to shim things up with some veneer and the fit is pretty good.

The dummy heel block I used was routed at right angles to grain direction and there were problems with tear out on one side of the dovetail. As most heel blocks are glued in with grain running parralel to long axis of the dovetail I dont imagine this would normally be a problem. Any thoughts on avoiding such tear out if wished to install a heel block with grain oriented as in photos?

kiwigeo38955.305625

technically speaking, a dovetail joint is a mortise and tenon joint, just a far more complex version than the straight mortise and tenon.

you do a short climb rout on that side.

as i recall, when s-m included the segment on the shop tips video they demonstrated using the dovetail bit for the whole task, rather than the more customary preliminary hogout with the straight bit.

remember that the mortise has to be about 1/8" deeper than the tenon's customary 3/4".

Michael,

Thanks for clarification on the dovetail/ M and T terminology.

Will try a climb cut. I suspect grain orientation is the main problem as well as taking alot in one cut with the dovetail bit. On my guitars the grain of the heel block normally runs at right angle to sound board so I would expect less problems with run out.

Roger on the clearance between bottom of dovetail male tounge and the cavity. My tounges are 16mm deep and cavity is 19mm deep. This is one thing thats pretty clear in the brief instruction sheet that came with the Stewmac router bit.

Cheers kiwigeo38955.8373032407

[QUOTE=kiwigeo] I suspect grain orientation is the main problem....On my guitars the grain of the heel block normally runs at right angle to sound board so I would expect less problems with run out.
[/QUOTE]
Careful, though. You also don't want to blow out a chunk of your soundboard while routing your mortise.

Thanks Carlton...thats one more thing to worry about.

Ive been playing with this &&&&&&**%%% jig and bit for 5 days now and its starting to drive me nuts. Holding the work tight in the jig is one issue that needs addressing. Forward plan is to build an adjustable cradle ala LMI manual to hold the neck firmly. The tenon template also needs some repair work after I stupidly raised the cutter without stopping the router and making sure the cutter was going to clear the template.

Had a nightmare in bed last night in which the jig featured prominently which means Im thinking too much about the thing.

HI Martin

Sorry to hear about your troubles with your dovetail cutting. I use a M and T joint.

The link below shows the clamping system I use and further down you can see how others hold the neck, hope this helps.

Woolson Jig Link

Thanks Russel,

Got a French Polish job to do on a classical so the break from the dovetail jig will give me time to think more about the forward plan.

Cheers

to me the problem in russell's interpretation of the woolson jig is that it is not usable to cut a mortise in the body, either straight or dovetail, because the template is off to the side of the jig. this may not be a problem if one uses pre- mortised neck blocks, but i prefer to cut the mortise after the body is together.


the version of the layout shown in the post later in the link by terken, if a bit wider, would have room to do the mortise rout as well.

for those who have not settled on a particular assembly methodology, it might be less restrictive to build the jig so it is usable for both the mortice and the tenon.

Okay I decided to make up a neck jig following photos in the LMI Catalog/handbook and heres the end product of 3 days of work. It hasnt got all the fancy plastic handled knobs and other fine touches like the one in the LMI book but it works.


kiwigeo38960.0142708333

WOW Martin, one nice jig!

Martin,

I am in just about the same point in the process as you. Do you have a jig for cutting the mortice in the body yet? I have been sketching things out for about a week now but I haven't decided how to go about it.

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as i mentioned in my posts above, the same jig can be used to cut both the mortice and the tenon. it of course has to be wider than the one shown immediately above, and has to have slots to be able to interchange the different holddowns used for the body.

why build two when one will serve both purposes?

Not sure whether or not to build a seperate cradle for routing the body mortise. Need to have a think about it first. Primary aim of the exercise was solving the problem of having to fiddle with multiple clamps to hold the neck in position. The body merely has to sit with mortise surface flush against the template...a bit easier to achieve than with the neck.

[QUOTE=crazymanmichael] as i mentioned in my posts above, the same jig can be used to cut both the mortice and the tenon. it of course has to be wider than the one shown immediately above, and has to have slots to be able to interchange the different holddowns used for the body.

why build two when one will serve both purposes?[/QUOTE]

Michael, I can actually fit a dreadnaught body into my jig and get the mortise area sitting flush against the top of the jig. The neck clamping cradle can be pulled out and replaced with a suitable insert set up for holding the body secure. Still working on exact design of this.

Cheers

martin, i am surprized that it is wide enough given that you need room at the sides for the holddowns. the photos don't do it justice.

when doing the mortise it is very helpful for your mounting system to have have a pin, which can be accurately centered on the jig centreline, which engages the end pin hole. makes it easier to keep everything centred.

with enough width, the same tiltable mounting plate which is used for the neck can be used for the body by making the holddowns for the two parts interchangeable.crazymanmichael38961.4014236111

Yes, an end pin locater is an option. Dont think the main jig is long enough though. I built it from the Stewmac plans and I think they just expect you to use a couple of cam clamps in the waist area. In the LMI handbook Im using as a guide their body jig has an end pin locator.

Thanks for the comments and suggestions

Martin

WOW Terry, you just come up with great ideas all the time bud, nice jig too, thanks for sharing this bud!

Serge