Official Luthiers Forum!
http://www.luthiersforum.com/forum/

KD bolts on a dovetail neck?
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=23872		 Page 1 of 1
Author:  Corky Long [ Mon Sep 21, 2009 2:03 pm ]
Post subject:  KD bolts on a dovetail neck?
I'm pretty disgusted with my current attempt at a dovetail neck - somehow I managed to route the "channel" in the neck block way too far at the point of the "V", so that, even though the v of the neck fits into the channel perfectly, there's no contact at the tip. Thus, the joint doesn't resist in the most important direction - e.g. against the tension of the strings. oops_sign

On the next one, I'm going with a mortise and tenon, supported by KD bolts and cross dowels.

Can I use a set on this neck? e.g. can I use bolts and cross dowels to attack this dovetail neck to the nexblock? Clearly drilling the holes may be made more complicated by the angles in the dovetail, but I think this might be a workable solution to this self-imposed purgatory. In order to make the dovetail "right" I'd have to add significant mass (customized shims) in the neck block - I don't like the odds for that holding well. Thanks for your help.
Author:  truckjohn [ Mon Sep 21, 2009 4:15 pm ]
Post subject:  Re: KD bolts on a dovetail neck?
I think it would work just fine. Screws do a fine job of lining everything up properly...

Just take some time lining up the neck-body joint good and straight, clamp, and drill.

I like to drill M/T neck holes before the back is glued on, but you can do it just fine with an 90* angle drill and an extra long drill bit.. I ended up using an Air 90* drill for drilling the holes in the neck heel... the Air unit was $20.00 where the electric unit was $200.00

1st step is to drill 2 holes in the neck block from the outside. These need to be a generous slip fit for your knockdown screws.

Then line up the neck -- properly straight, on centerline, etc... and clamp it to the body for drilling.

Using the same size drill bit as in Step 1, drill back through those holes from the inside into the neck.

Now, you have located your holes in the neck for the threaded inserts. You can take the neck back off and drill the neck holes larger for the inserts with a hand drill, as subsequent drill holes will follow those 1st accurately placed holes.

3 cautions:
Don't drill thru the neck (Duh)

Make sure you don't leave the insert holes too tight... or you will split out your heel. The hole has to be at least as big as the largest unthreaded diameter of the thread insert.

Be sure to drill deep enough to leave clearance past the end of the insert for your screw... or you will split out your heel when you tighten down the neck.

Good luck

John
Author:  Barry Daniels [ Mon Sep 21, 2009 6:32 pm ]
Post subject:  Re: KD bolts on a dovetail neck?
Shims do not add weight and would be the proper way to address the problem.
Author:  Corky Long [ Tue Sep 22, 2009 2:04 pm ]
Post subject:  Re: KD bolts on a dovetail neck?
John - Thanks for the detailed instructions - and especially the cautions!
Barry - I think in my description of the issue I wasn't clear about my concerns. It's not weight that I'm worried about - it's the effectiveness of a shim on the "nose" of the dovetail. I've got lots of experience with shims on the sides - unfortunately - and they've worked fine. I just don't think this joint will ever be right without some creative solutions. Thanks
Author:  Terence Kennedy [ Tue Sep 22, 2009 2:29 pm ]
Post subject:  Re: KD bolts on a dovetail neck?
I recently converted an old Harmony to a bolt on neck after doing a reset. I drilled two 5/16" holes in the midline of the mortise and used transfer punches to mark the tenon.
Drilled generous holes for the inserts and used epoxy to help anchor them. So far so good, seemed to work just fine.

Image

Transfer punch coming through

Image

Tenon Marked

Image

Image
Author:  Mike Mahar [ Tue Sep 22, 2009 3:52 pm ]
Post subject:  Re: KD bolts on a dovetail neck?
I've done this once and it worked very well.
Get some epoxy putty. It looks like a gray Tootsie Roll.
Cut off a piece and kneed it.
Place it in the area of your dove tail mortise that needs to fill.
Cover your dovetail tenon with plastic wrap.
Set the neck. Some putty will squeeze out. Remove the neck and scrape off the excess.
Re-set the neck and remove and additional squeeze out. repeat.
Once the neck is firmly set in position, remove it. The plastic wrap will probably be stuck to the epoxy putty. Remove it.
Wait for the putty to harden.
Reset the neck. The putty can be shaved with a chisel just like wood.
Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/