Neck/Headstock Scarf Joint Jig

[Mateyboy]

Hi

I've been thinking of some way to make a jig where I could use a router to 'plane' a neck/headstock scarf joint with a router after cutting it on a bandsaw/handsaw/jigsaw/any-saw. I came up with the attached jig. I'm going to make it up out of MDF and give it a try. I suppose it might also be useful for sanding the scarf joint.

It's fairly cheap to make so can't see any reason why I shouldn't give it a go and try it out on some cheap wood.

Thoughts?

Edited February 24, 2017 by Mateyboy
Changed title.

[curtisa]

That's pretty much how all the standard scarf router planer-type jigs are done. Yours just flips the side rails so that the router travels horizontally instead of at the downward angle of the scarf cut.

My only suggestion is that you'll need some way of clamping your workpieces. At the moment I can't see how you can secure your work while the router is running. Also consider that whichever way you decide to clamp the pieces in, make sure the clamps can not come in contact with the router bit while in use.

[Mateyboy]

Hi Curtisa

Yeah, I didn't like the idea of running a router down the angle. I've seen people sanding down the angle.

I'm thinking that if one of the rails is extended I can clamp the neck to it (as attached), not sure how sturdy it will be though. Like I say it's cheap to make and not too time consuming, if it doesn't work it's no biggie. I guess the only pain would be if it damaged a neck blank.

[soggybag]

Nice idea. Might be good to add more platform on the top for the router to rest on. 

[Mateyboy]

I've used this jig about 4 times now and got fairly good results. I'm a bit better at making more accurate jigs now so I will probably make it again. ;-)

 

[Prostheta]

Sorry for coming in so late in the game; it's a great idea. Reducing the amount of work and thought processes required when handling a power tool is always a good thing.

In fact, I have been in the middle of documenting my compound scarfing jig, and this feature would be an excellent improvement upon it. If I incorporate this into an iteration of that design, I would want to give you full credit of course. That is genuinely excellent.

[Prostheta]

This is where the prototype for the existing design is. I'll have to put some thought into how it would best be flipped and still made adjustable.

[Mateyboy]

That looks much more fancy than mine. 

I'm never too keen to run the router at an angle. When I make my jigs if I can keep the router level I'm happy, although I can see how your design would make clamping the neck a lot easier. I generally use double sided  sticky tape to attach the two pieces together then clamp the longer piece to the jig. I've not had any issues yet.

 

7 minutes ago, Prostheta said:

Reducing the amount of work and thought processes required when handling a power tool is always a good thing.

 

I'm not too great with hand tools and my first build had loads of mistakes in it. I'm currently building another neck and if I can build a jig to eliminate some of the hand tool elements and almost 'machine' a job then up for making a new jig. That's just my preference and part of the learning process for me. 

[Prostheta]

I think the biggest issue with tape is minor play. All tapes have it under shear, so I'd be a little circumspect about using it on (relatively) heavy pieces of wood to hold them against gravity. Any movement can mean cleanup at best, disasters at worst.

In principle, yours has several advantages. Unless you want to bash heads together on a joint design, I am blatantly going to steal your idea! 

In all seriousness, that is excellent. Its upended my approach (no joke intended) and I think it is better for that. The obstacle that still exists is clamping. That isn't too much of an issue however.

[Prostheta]

23 minutes ago, Mateyboy said:

I'm not too great with hand tools and my first build had loads of mistakes in it. I'm currently building another neck and if I can build a jig to eliminate some of the hand tool elements and almost 'machine' a job then up for making a new jig. That's just my preference and part of the learning process for me. 

 

To me, that says a lot and it has definitely been one of the reason I've back-and-forthed over various approaches to describing builds. All of the builds documented in Season One will be done to a level that should be achievable for everybody, without expectation of expensive machinery or pre-existing skills. 100% accessible. This is entirely why I think your suggestion on re-orienting the jig has a lot of genuine traction.

It's a great part of the improvement process. Making jigs and "machining" a build is not sterilising it, it's planning to succeed. A well-designed and for-purpose jig will succeed on its strengths, and the workpieces they produce all benefit from that consistently. It's everything we're working towards.

[Mateyboy]

18 minutes ago, Prostheta said:

I am blatantly going to steal your idea!

Go for it.  I'm interested in how it turns out. It is something I'd be interested in seeing how you clamp the wood. One of the flaws in my design is that the neck has to hang over the edge of the bench because of the angle - I clamp  the two pieces to the overhang and then stick them together. If you can sort the clamping out then I don't see that being an issue.

 

21 minutes ago, Prostheta said:

Any movement can mean cleanup at best, disasters at worst.

Yeah, I generally have to do a bit of sanding to clean up afterwards. Getting the clamping sorted would be great. I will have a think but you will probably come up with something.. 

[Norris]

Just a thought on the clamping. Would making the jig taller, wider & longer then allow you to use a bar clamp across the top of the workpiece, securing down into the angled bed? In other words, two captive flange nuts set into the angled bed, then a bar the width of the bed that bolts down across the workpiece. You might also want to incorporate a side rail to allow for alignment of the workpiece with a cut-out for the clamping bolts

Sorry, I haven't got any CAD on my work PC or I'd knock up a diagram

[Prostheta]

I was thinking of drilling holes through, epoxying a couple of t-nuts into a strip of plywood and having a pair of knobs underneath (fnar). As long as the metal is out of the reach of the spinny thing, that would work.