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Dovetail Problem

Posted: Tue Nov 05, 2019 10:42 pm
by oldlefty
Hi gang- first post here. I've built a few electrics, a few dulcimers and a uke, this is my first acoustic. StewMac OM kit, mostly going well until.... "the dovetail". I've memorized the John Hall videos (THANK YOU!), but I got a little carried away on the cheeks trying to get the neck angle right and now the end of the neck is up against the neck block with a gap still on the sides of the heel cheeks.

I'm thinking I can still take a little off the end of the neck tenon to buy me some room without having to move the bridge very far and get into problems with its location over the bridge plate? Just 1/8" or less. Any other ways to attack the problem I've created for myself? Thanks!

Re: Dovetail Problem

Posted: Wed Nov 06, 2019 1:27 am
by Diane Kauffmds
I did the same thing on my first build. I would take a little off of the tenon, and assuming you have established all of your angles, and the only problem is closing this gap, scribe sand to close the gap.

If you look closely at the photos, you'll see that I've removed material from under the cheeks, making a small "valley". This ensures that the outside edges of the heel sit on the shoulders of the guitar, and that there are no rounded areas of wood holding the heel off of the shoulders.

John Hall demonstrates this in his video.

https://youtu.be/mokxzeYOd_0
PicsArt_01-10-07.03.24.jpg
PicsArt_01-10-07.02.30.jpg

Re: Dovetail Problem

Posted: Wed Nov 06, 2019 6:20 am
by MaineGeezer
It is really easy to chase your tail trying to get the angles and fit to converge.
As Robbie O'Brien oten says in his instructional videos, "Of course it's never happened to me, but it happened to a friend of mine...."
You might also be able to make the dovetail pocket a little deeper so you don't lose bearing surface on the tenon.

Re: Dovetail Problem

Posted: Wed Nov 06, 2019 9:43 am
by jread
fwiw, i did the same thing on my kit. I made the mortise a lil deeper as it didn't seem to be so much as to weaken it. Good thoughts on which direction the saddle would move as you correct that! I didn't think of it and along w/ some other mis-calculations when gluing it in ended up w/ my bridge pin holes pretty close to the the back edge of my bridge plate. Was nervous about that but it all worked out fine and I don't expect that this will cause me issues. If the holes were on the front edge, i'd be considering moving it, i guess.

Re: Dovetail Problem

Posted: Wed Nov 06, 2019 4:32 pm
by Diane Kauffmds
jread wrote:fwiw, i did the same thing on my kit. I made the mortise a lil deeper as it didn't seem to be so much as to weaken it. Good thoughts on which direction the saddle would move as you correct that! I didn't think of it and along w/ some other mis-calculations when gluing it in ended up w/ my bridge pin holes pretty close to the the back edge of my bridge plate. Was nervous about that but it all worked out fine and I don't expect that this will cause me issues. If the holes were on the front edge, i'd be considering moving it, i guess.
Depending on where your fretboard lands on the neck when you place your 14th fret at the correct location (,or 12th fret, for a 12 feet guitar), you can move your nut onto the headplate, instead of sitting it on the neck level with the board. This simply requires that the bottom of the nut be ground with an angle matching the headstock.

Hopefully my drawing isn't confusing. This will keep your bridge in the right position to your bridge plate. If you find that you're only losing a little depth between your fingerboard and headplate veneer, when your fret 14 is free of the body, you can just thin the nut a bit instead and stick that puppy right in there.

Re: Dovetail Problem

Posted: Wed Nov 06, 2019 10:26 pm
by oldlefty
Thanks everyone for your quick replies! I'll give it a try and let you know.

Re: Dovetail Problem

Posted: Thu Nov 07, 2019 11:16 pm
by phavriluk
Plagarizing the OP a bit, the only way I was going to become an 'old lefty' was to not go near dovetails. I found I could do bolt-ons that satisfied me without blowing a gasket, which was going to happen if I tried to do a dovetail. I regard dovetails as a confusing high-skill process that would eat up way too much time and heartache when something I understood was available behind a different door.

Re: Dovetail Problem

Posted: Sat Feb 29, 2020 2:39 pm
by oldlefty
Well it all worked out in the end. I did take enough off the tenon to leave a gap, ended up using two shims on one side and one on the other to get the neck straight and level at the top. I'd walk away from it for a few days or a week a few times to let my head clear. Finally got it to where I could move on. Not perfect, good enough, next one will be better.

Just finished it up and I'm delighted so far. It was the "Limited Edition" kit with old growth red spruce over Madagascar rosewood. I built it as a lefty, so I reversed the tone bars, cut a lefty pickguard, nut, and bridge, and (gasp) made a lefty bridge out of a block of ebony! Lefty bridges with a 2 5/16" spacing are not easy to find. But it was a real confidence-builder! I made three and picked the best one.

Thanks again for the help and encouragement getting over a rough spot.

Re: Dovetail Problem

Posted: Sat Feb 29, 2020 3:50 pm
by jread
So nice!!

Re: Dovetail Problem

Posted: Sat Feb 29, 2020 5:52 pm
by tippie53
winner