Banjo mandolin heel problem

[Peter Wilcox]

An acquaintance wants me to make this instrument playable - looks are not important. She says somebody else worked on it in the past without success.

To me it looks like the heel and the rim where it attaches have been messed with (in several ways) so the neck angle is way off and the action way too high. The neck is bolted on, both with a probably original bolt from the inside into an insert in the heel, and from the outside (probably a later try at a fix) by a machine screw into an insert in the rim. Both the heel and the rims have random chunks carved out. It may be this is not the original neck, and somebody tried to make this one fit.

My thought is to fabricate a wedge to put between the heel and the rim to hold the neck at the correct angle and just bolt the neck back on with the existing hardware.

Also, the tailpiece, such as it is, doesn't hold the strings off the rim and head where they cross - I don't know if this needs to be addressed also.

Any suggestions appreciated.

[Peter Wilcox]

More pics.

[Peter Wilcox]

Moree pics.

[Michael Lewis]

Does the end of the fingerboard contact the metal rim? I think it needs to have more support than just a bolt through the resonator wall. This is a cheap grade of instrument, so if you want to make it playable you will need to put some structure into it.

If the fingerboard contacts the metal rim that should provide enough structure so the neck should not pull up more than it is, but you must make sure the heel is made solid to the resonator. You may need to put a shim between the end of the fingerboard and the metal rim.

Remember, no good deed goes unpunished.

[Peter Wilcox]

You may need to put a shim between the end of the fingerboard and the metal rim.

No, the fretboard doesn't contact the rim when the neck is set at the proper angle. That shim is a good idea - thanks.

[Wayne Brown]

Peter, thanks for posting this. I had one of these banjo-mandolins to come through my shop about two years ago. It was exactly like yours and had the same problem. There was no label and my research said it came from Sicily. The neck was attached with two "nails", making it nearly impossible to remove. It looks like someone encountered the same problem with nails (maybe) and tried to fix it. What it really needs is to have a dowel or metal rod going from the neck to the opposite side of the resonator. Also, on mine someone had installed a mandolin tail piece and bent it upward to fit.

[Peter Wilcox]

Thanks, Wayne. I tried wedging the neck at the correct angle, but over night it slowly pulls forward. My plan now is to put in a dowel stick toward the floor of the resonator, and a shim under the end of the fretboard to the metal rim.

[Peter Wilcox]

The shim on the fret board was no help - the board started to bend. I back set the neck and added a 'maple bar' in the floor of the resonator with deck screws (if glue doesn't do it, screw it).

[Peter Wilcox]

The action at the 12th fret is still a little high (3/32") but playable. Thanks for your suggestions.

[Michael Lewis]

A strut from the highest point available on the heel and under the head and metal rim, running to the back end of the "pot" where the tail piece is attached. It should be snug with no gap so it supports the upper part of the neck. You have the lower part of the neck screwed to the maple bar, so that takes care of the tension side of the neck, the strut I suggest should take care of teh compression part of the stress.

[Peter Wilcox]

The metal rim is thick and strong, and fits tightly into the resonator, so takes care of the compression aspect. I just had to rework the heel joint to get the action down to 1/16". The problem as I see it is the head, which sags under the bridge to varying degrees depending on the string tension, humidity and probably other factors, so you can't shoot a straightedge along the fretboard to see where it hits the bridge like a guitar. It's a little by little adjustment for me, and each time I have to re-attach the neck, restring and re-tune it. It must be tough setting up banjos.

What a PITA, but it's done. I hope I get it back to her before it explodes. Thanks again for the advice.