Tips on neck joint creation

[eliseguitars]

Hi everyone - I am an amateur builder and I am working on my first non-kit scratch build.

I am trying to figure out the best method for creating my neck joint. I want to use a mortise and tenon joint and I am leaning towards the Robbie Obrien LMII neck joint rig. I plan to be making quite a few more guitars so I am willing to spend the money.

Alternatives include a simple mortise/tenon routing template from stewmac or the more solid elevate guitar neck joint template (that allows for an angle to be set).

What are folks using to make their neck joints? Anyone like the obrien rig?

Thanks!

[Rudy4]

Originally Posted by eliseguitars

Hi everyone - I am an amateur builder and I am working on my first non-kit scratch build.

I am trying to figure out the best method for creating my neck joint. I want to use a mortise and tenon joint and I am leaning towards the Robbie Obrien LMII neck joint rig. I plan to be making quite a few more guitars so I am willing to spend the money.

Alternatives include a simple mortise/tenon routing template from stewmac or the more solid elevate guitar neck joint template (that allows for an angle to be set).

What are folks using to make their neck joints? Anyone like the obrien rig?

Thanks!

The O'Brien joint could be more correctly referred to as the Compiano neck joint, although he doesn't claim to be the creator.

I think O'Brien's joint has too short of a tenon, but it obviously works. Compare that to Compiano's joint:

https://www.cumpiano.com/an-improved-neck-body-joint

I use a variation of that system, with two barrel nuts embedded vertically, similar to the Taylor neck joint. You can find the full size downloadable pdf of this plan here in my posts.



Embrace the art of making your own tools and jigs as generations of instrument makers have done. The supply houses are quick to market something to extract your money from you, though.

[Fathand]

The Obrien jig likely works fine but it appears expensive and takes a lot of room to store it.


I made matching mortise and tenon templates from mdf about 5 or 6 inch square.

I cut the heel end of the neck to the required angle on the bandsaw, about 1 or 2 ° off square as needed to match the guitar top. https://www.flickr.com/photos/194462...7720296630125/
I drywall scew the template to the neck through 2 holes in the template. I put it all in a vise then use a router to cut the tenon. Since it is indexed to the already angled neck end, the cheeks follow the same angle and there is usually little final fitting to do later.

https://www.flickr.com/photos/194462...7720296630125/

In the picture I clamped the neck in the vise but I now prefer to clamp the template and let the neck hang.
The 2 screw holes are later enlarged for threaded inserts.

The matching mortise template is clamped to the guitar through the soundhole and screwed to the workbench. https://www.flickr.com/photos/194462...7720296630125/

More pics

https://www.flickr.com/photos/194462...7720296629122/
https://www.flickr.com/photos/194462...7720296629122/

https://www.flickr.com/photos/194462...7720296629122/
https://www.flickr.com/photos/194462...7720296629122/

Some builders are also known to forego the M&T joint and butt joint the neck on with bolts or just glue like in the old David Russell Young book.

Good luck, practice on scrap

[eliseguitars]

Originally Posted by Fathand

The Obrien jig likely works fine but it appears expensive and takes a lot of room to store it.


I made matching mortise and tenon templates from mdf about 5 or 6 inch square.

I cut the heel end of the neck to the required angle on the bandsaw, about 1 or 2 ° off square as needed to match the guitar top. https://www.flickr.com/photos/194462...7720296630125/
I drywall scew the template to the neck through 2 holes in the template. I put it all in a vise then use a router to cut the tenon. Since it is indexed to the already angled neck end, the cheeks follow the same angle and there is usually little final fitting to do later.

https://www.flickr.com/photos/194462...7720296630125/

In the picture I clamped the neck in the vise but I now prefer to clamp the template and let the neck hang.
The 2 screw holes are later enlarged for threaded inserts.

The matching mortise template is clamped to the guitar through the soundhole and screwed to the workbench. https://www.flickr.com/photos/194462...7720296630125/

Good luck

This is great! I may have been overthinking this whole process. I worry a lot about the neck joint angle - probably more than I need to. I might try making some test necks using some scrap wood.

[Fathand]

Originally Posted by eliseguitars

This is great! I may have been overthinking this whole process. I worry a lot about the neck joint angle - probably more than I need to. I might try making some test necks using some scrap wood.

I tested my templates with just some laminated 2x4 blocks about 4 inches cubed rather than making whole necks.

[printer2]

I also took pieces of a 2x4 and routed dovetail joints into them and made adjustments and did the next one, done many times until I was satisfied I would not (hopefully) screw it up on a guitar. Ended up working. Nothing like getting your confidence up by practice, practice, practice. Applies with building also. Can not really hurt a test piece.

[Brad Howard]

I have decided to use the Compiano type joint on a current build and considered the O'Brien jig but decided it required too much room for storage so am working on building my own templates. The idea of cutting the neck stock to the correct angle before routing and these photos are very helpful and timely!

Would you mind sharing which router bits you use? It looks like the routed area is deeper than the cutter so I was wondering if the bearing just rides on the previously routed area as you continue to plunge.

Thanks.

[phavriluk]

I started scratchbuilding using the neck attachment system offered by 'Luthier's Cool Tools' (Bolt-on Neck Kit). Sixth one so far. Excellent documentation. Buy their string spacing guide, too (I've used their 6-string and 12-string templates).

[Fathand]

Originally Posted by Brad Howard

I have decided to use the Compiano type joint on a current build and considered the O'Brien jig but decided it required too much room for storage so am working on building my own templates. The idea of cutting the neck stock to the correct angle before routing and these photos are very helpful and timely!

Would you mind sharing which router bits you use? It looks like the routed area is deeper than the cutter so I was wondering if the bearing just rides on the previously routed area as you continue to plunge.

Thanks.

I use pattern bits, similar to these. https://www.amazon.ca/Flush-Trim-Pat...NsaWNrPXRydWU=

Yes the bearing can ride on the previously routed area or you can switch to a longer bit or you might have to do both depending on depth of mortise and thickness of template.

You can also cut out the mortise and tenon on a bandsaw and plug the bottom of the mortise before gluing the back on, then hiding the plug with binding but it's more work and trickier to be accurate. You wind up with a square bottomed mortise and tenon which doesn't really matter.

https://www.flickr.com/photos/194462...7720296630125/

https://www.flickr.com/photos/194462...7720296961058/

[eliseguitars]

Originally Posted by Fathand

You can also cut out the mortise and tenon on a bandsaw and plug the bottom of the mortise before gluing the back on, then hiding the plug with binding but it's more work and trickier to be accurate. You wind up with a square bottomed mortise and tenon which doesn't really matter.

This was going to be my next question - what are the other ways to cut the mortise and tenon other than a router. I can see cutting the tenon with a saw is doable, but the mortise is a little more tricky.

[Fathand]

Originally Posted by eliseguitars

This was going to be my next question - what are the other ways to cut the mortise and tenon other than a router. I can see cutting the tenon with a saw is doable, but the mortise is a little more tricky.

The mortise is easier because you don't have the compound angles like on the neck heel cheeks. I did a couple ukes and my first guitar this way.You cut it before the back is on the guitar. The top can be on or not. i think I did it with it off. You just cut into the neck block the width of the tenon then fill the bottom 1/2" or so with wood that will be covered with the neck heel and binding. In this pic, you can see the shape of a sawn out mortise and the plug at the bottom.

https://www.flickr.com/photos/194462...7720296961058/

Overall, I find the router easier and more accurate once you make templates but there is so much invested in a first build, sometimes you have to make do.

[Brad Howard]

Thanks for the additional info.

Routing the mortise and tenon has worked OK for me in the past doing both pieces on a router table before the neck block is assembled to the sides but that requires a lot of hand work later on to get the neck angles just right. This time I want to switch from threaded inserts to barrel nuts and route the mortise after the body is assembled. The longer tenon requires a deeper mortise than I can cut with using a guide bushing with my current plunge router. Pattern bits might be a better choice.

[redir]

Originally Posted by eliseguitars

This is great! I may have been overthinking this whole process. I worry a lot about the neck joint angle - probably more than I need to. I might try making some test necks using some scrap wood.

It's crucial. You need to get that set right from the start. I used to worry about it too so I sat down with pencil and poster board and drafted it out 1:1 scale and built up a system to get it right. Now I don't worry about it.

What ever joint you decide to go with definitely consider neck angle.

[Fathand]

Originally Posted by Brad Howard

Thanks for the additional info.

Routing the mortise and tenon has worked OK for me in the past doing both pieces on a router table before the neck block is assembled to the sides but that requires a lot of hand work later on to get the neck angles just right. This time I want to switch from threaded inserts to barrel nuts and route the mortise after the body is assembled. The longer tenon requires a deeper mortise than I can cut with using a guide bushing with my current plunge router. Pattern bits might be a better choice.

I used to use the barrel nuts but I switched to inserts, they are easier for me and I can't see them ever coming out. I don't like the sideways ones, I feel they weaken the tenon unless it's quite long which requires a deeper mortise. The vertically mounted ones like Rudy uses are good but I find tricky to get accurate position.

The pattern bits made it easy to make my templates without calculating the guide bushing. Just tape a tenon shaped piece of wood to mdf and copy it with the pattern bits.

By cutting the neck end to match the side to top angle then attaching the template, the cheeks are routed to the same angle. The last one required no flossing at all, a bit lucky but most didn't require much.

[Brad Howard]

I've never had a problem with threaded inserts though my experience is limited to a small number of builds, the oldest now in service for about 5 years. Barrel bolts are interesting but thinking this through, the best step on this current build is to route using templates and fasten with threaded inserts, limiting process change to one variable at a time.

Thanks again for sharing your approach.