Dovetail joint fit need help with correction

[ken cierp]

I should also point out that in photo #2 the bottom of the finger-board is not yet touching the top -- so that means the straight edge end at the bridge is still lower then the top of the bridge. In other words the angle of the FB plane is still not sloped enough. Head stock needs to be tipped more away from the sound-board. In the end you may have to install a tapered shim under the fingerboard extension --- also not uncommon -- one professional maker here in Michigan does that all the time.

[rusty999]

I should also point out that in photo #2 the bottom of the finger-board is not yet touching the top -- so that means the straight edge end at the bridge is still lower then the top of the bridge. In other words the angle of the FB plane is still not sloped enough. Head stock needs to be tipped more away from the sound-board. In the end you may have to install a tapered shim under the fingerboard extension --- also not uncommon -- one professional maker here in Michigan does that all the time.

You are correct there ken, but I had to pull out the neck a little to take the photo and show you my problem. In actual fact I can push the joint tight together thereby having the bottom of the fingerboard sitting on the soundboard---but then as you said my straight edge will be below the bridge by about 1/8th.
I would be one very happy chappie if I even thought I could get away with a tapered shim and make this all come together as its cracking me up at this stage

I intend to take your advise and get the book you mentioned.

Just one other thing. When I insert a tapered shim as you suggest how will I fill the gap between the Rim and the Heel as I can see there will be a gap left even after shimming. Will I need a piece of mahogony to push in and fill it ?

[ken cierp]

The gap at the body is going to close because you are going to change the angle on the neck heel cheek --- are you getting that idea?

[rusty999]

The gap at the body is going to close because you are going to change the angle on the neck heel cheek --- are you getting that idea?

ahh ...Just let me digest that Ken, certainly looks like it may work so I'm going back to the workshop again--no computer signal out there unfortunately.

[ken cierp]

Excuse me -- may work????

Its how its done -- I was once given some very good advice.

"Don't start vast projects -- with half vast ideas"

Proven method (which you have been given here and detail in Bill's book) -- mathematics --execution -- patience

Good luck if you take a different course. $.02

[rusty999]

Excuse me -- may work????

Its how its done -- I was once given some very good advice.

"Don't start vast projects -- with half vast ideas"

Proven method (which you have been given here and detail in Bill's book) -- mathematics --execution -- patience

Good luck if you take a different course. $.02

Sorry Ken, I was not being flippant by my comment but merely saying that it looks like that might work for me--thats Irish for Looks Good !!
This is a first time experience for an old guy like me so be gentle with me man lol


Ok, I did what you suggested but I still had no option but to use shims and heres where i am right now.

The joint is not as loose as it was--just lets say it has tightened up a bit--but the neck angle is slightly out so I was wondering is it common practise to shave a little from the bridge ? My straight edge just barely comes to the top of the bridge but could do with more clearance

I have not yet glued in the neck so I'm open to suggestions. And with regard to the joint I assume its the tightness of the joint that holds the neck from pulling forward when the strings are on full tension and not the glue ? So with that in mind maybe I need to get more shims in there ?

Thanks again for all your suggestions and help thus far
Rusty

[ken cierp]

Why would you glue anything before the parts fit?

How much material did you remove from the heel cheeks? If you did not change the angle you did not remove enough material -- simple geometry.

Need more pictures and will need many more measurements -- sorry this is a tedious process when its done long distance (ten minutes in the shop). I understand that you may not want to interact to that degree and that's perfectly OK, but lets not waste each other's time. Trial and error -- crossing ones fingers doing this and that and hoping for a miracle is not my style -- my background instills in me the need to have and use an organized plan of attack. The true fix for this issue requires precision. Not having a sound mathematical plan can yield a joint that looks OK but could very well lead to other serious problems when it comes time to string up and make the guitar playable. Now is the time to get it perfect.