Armrest keeps falling off

[Kash]

I have a McClung armrest for my Phoenix mandolin and I really like the way it makes my picking hand move around the mandolin. There's only one problem- it doesn't clamp quite right to the top/back. It will occasionally fall off while I'm playing. I'm pretty sure I have the armrest tension right. I think that is because the phoenix mandolin has a beveled top and back instead of the more typical binding arrangement. Try as I might, I can't think of a good way to make it fit better. I'm pretty handy with tools (was a professional furniture maker for a while) anyone have any ideas?

[Ray(T)]

Reminds me of a problem I had many years ago trying to keep a carpenter jack on an old Ibanez. The top and sides met at slightly more than 90 degrees so it kept sliding off. The backs and tops of most mandolins are slightly dished so this doesn’t happen and I remember improving “adhesion” with the judicial use of double sided tape at the contact points.

[soliver]

I'm about 99% sure that Doug uses the same hardware that I use on my armrests, and I too have had trouble with them coming off folk's Mando's when they don't have a well defined corner where the sides meet the top and back. Particularly if they are rounded over like on some Weber mandolins. I have thought of trying to create an additional "plate" made of a piece of 1/16" thick metal such as aluminum with padding that would have holes that the threaded posts of the clamping foot would fit through and would extend about 3/8" to 1/2" to go beyond the existing foot... Whatever is used as padding on the existing foot could be removed and the new plate could be glued in place with a small dab of something like JB-weld.... I'll try to include a sketch...

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This is just an idea I've had, ... I'm not sure if it would work or not.

[Kash]

Soliver,
I bet that would work. I'll have to take a look at the armrest & bracket to confirm that there's enough length on the mounting screws. I wonder if the top of the armrest needs a similar change as well, or if this would be enough.

[soliver]

Not sure, Kash... I've never seen one of the McClung's in person so I'm not sure what the underside of the wooden rests look like. Mine may have a wider base, I make them about 3/8" wide.

[UsuallyPickin]

The problem is one of no matching angles. The mechanical tension is not spread evenly across the gripping surface. So add cork to the gripping surface so it matches the angle of the face and back of the instrument. R/

[pops1]

Send me your Phoenix and I will see if I can figure it out, if I can't I'll send it back in a month or two. :mandosmiley:

[Mandobart]

The problem is one of no matching angles. The mechanical tension is not spread evenly across the gripping surface. So add cork to the gripping surface so it matches the angle of the face and back of the instrument. R/

Yep I add either cork or leather (chamois) to the contact point on my homemade arm rests.

[Phil Goodson]

Wonder what a glob of silly putty under the contact points would do?:confused:

[Zach Wilson]

Yep I add either cork or leather (chamois) to the contact point on my homemade arm rests.

The carpenter jack attached to LR Baggs radius kept slipping off at a gig. I'd have to "pop" it back on in between every song! So during a break in our set I took the small strip of leather laced between the strings behind the bridge and used it under the foot of the LR Bagg's. Worked like a charm!

This application may work for you.

[sblock]

As others have said, you need some kind of a padding or caul to better adapt the shape of the flat armrest to the curvy wooden side of the mandolin. A strip of cork or leather can work well for this purpose. However, cork will crumble over time, and you need to be sure to use a type of leather strip whose tanning chemicals won't interact with the finish (a bit of chamois is usually good for that). You can also use a short section of inert, silicone rubber tubing, slit down one side, and placed over the rounded edge of the mandolin, between the armrest and back. This material is both spongy and grippy, and it will not mar the finish.

[Kash]

It looks like more than cork is needed, at least on the back. Here's a couple of pictures.
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If you look closely, you can see how the bevel affects the clamping surface.

[HonketyHank]

Wonder what a glob of silly putty under the contact points would do?:confused:

Probly rot the finish. But a couple of big wraps of duck tape would probably hold it and damp the stray vibrations between bridge and tailpiece at the same time. < ;-)

[Kash]

I decided to go with Soliver's idea. I made a small plate and just glued it to the back of the clamp. The glue is setting now, so I'll try it out tomorrow.

I used aluminum, because i had some laying around. If it works well, I'll probably replace it with some stainless so that everything matches.
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[Kash]

Just put the modified armrest back on, it works great!
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[Zach Wilson]

Nice work!

[ajh]

Sorry to catch you so late in the process. I had a similar issue a few years back. What worked for me was (I only had to do it to the top surface):
1. Strip off the cork on the armrest
2. Wrap the entire mandolin body with a couple of layers of SaranWrap going right where the entire armrest contacts the body. Be generous to accomdate overflow.
3. Tape a sheet of aluminum foil over the armrest/mandolin top contact area with blue tape onto the SaranWrap.
4. Smear two part epoxy or JB Weld onto the bottom of the armrest.
5. Clamp the armrest to the body and allow the epoxy to smoosh out the sides.
6. Let dry.
7. Cut off overflow with a razor knife. Trim the bottom of the armrest as needed to keep the epoxy off of the mandolin top.
8. Apply cork using carpet tape. Be careful about what kind of cork you use. There are two different kinds. Forgot which one is inert.

Might not work exactly the same for your instrument, but should give you some ideas.

[mcgroup53]

My advice is also buy a proper armrest/chinrest tool. The homemade ones that come with most armrests are crap. Buy a tool that's designed to give you proper control and adjustment on the screws:

https://www.amazon.com/ammoon-Violin-Screwdriver-Wrench-Accessory/dp/B01JOQX2ZU/ref=sr_1_3_sspa?crid=291E2P8453QKT&keywords=violin+chinrest+tool&qid=1549848037&s=gateway&sprefix=violin+chinrest+tool%2Caps%2C165&sr=8-3-spons&psc=1

Works great and lets me perfectly dial in how tight I need the armrest to be

[Ray(T)]

..... and if it still comes off, you can always drill a couple of holes in it and screw it on :grin:

[Kash]

..... and if it still comes off, you can always drill a couple of holes in it and screw it on :grin:
:)):)):))

[soliver]

Hey, I'm late getting back to this... Good work Kash! I'm glad that worked out!

[Doug Edwards]

Another suggestion is to remove the barrels and back the top screws out a bit. This would allow the base of the armrest to sit farther away from the edge of the top. Adding a plate or such works too.

These beveled edges always present a problem.