Bridge Thumbwheel questions

[McCandolin]

I'm coming to the end of my first build, a from scratch a-style mandola, and i want to make my own bridge for it. I don't trust my setup skills far enough to forgo the wiggle room of having an adjustable bridge so i was wondering where the posts and thumb-wheels can be bought at.

Also, i have read many times on the cafe that there is a style of bridge that lets you adjust it under full string tension, can the hardware for that kind of bridge be purchased?

And in both cases are there gold (plated? colored?) thumb-wheels? I'm using a lot of bronze in the instrument as an accent and gold tuners and i would like for the thumb-wheels to match.

Thanks for the help!

[sunburst]

"Standard" thumb wheels can be had from Steve Smith at Cumberland Acoustic in nickel or gold plating, along with the posts.

I think it's probably the Brekke bridge that might be adjustable under string pressure, I don't know if you can get that machinery, but contacting Vern Brekke might be a way to find out.

[Bob DeVellis]

There are mandos (like my Cohen C#) that use hex nuts instead of thumb wheels on the threaded posts. With an appropriately sized open-end wrench, those will allow adjustment at full string tension.

[Dave Cohen]

You can pay more through specialty shops lilke Stew-Mac or the individuals mentioned, or you can use hardware. Iirc, the Gibson adjusting posts are 5-40 setscrews. Or you could use 6-32. Or you could use threaded rod in either of those sizes. As for the adjusting nuts, or "thumbwheels", I use the appropriate size hex nuts, as mentioned. Or, you could find knurled nuts or something that could be trimmed into that configuration. Early on, I used some 6-32 brass cap nuts, and just cut off the caps leaving the knurled part, and filed and polished to make the knurled thumbwheels. I later decided that I liked the functionality of hex nuts. They give up something in appearance to the knurled thumbwheels, but as long as they are small, they are not terribly noticeable.

http://www.Cohenmando.com

[Bill Halsey]

Also, i have read many times on the cafe that there is a style of bridge that lets you adjust it under full string tension, can the hardware for that kind of bridge be purchased?

Any Gibson-style adjustable bridge under full string tension may be easily adjusted by inserting a screwdriver between the bridge and saddle near the adjuster, and giving it a twist to relieve the string tension on the thumbwheel.

[Mike Bromley]

Any Gibson-style adjustable bridge under full string tension may be easily adjusted by inserting a screwdriver between the bridge and saddle near the adjuster, and giving it a twist to relieve the string tension on the thumbwheel.


Doesn't that leave some kind of a mark?:disbelief:

[Bill Halsey]

I just outlined the principle. You could pad the screwdriver with cardboard, or use a different tool. Whatever. Mando players are a resourceful, clever lot.

[Timbofood]

Bill showed me this last summer and boy was it a "light bulb" moment! As long as you don't do something like drink a beer while you're doing it, it would pretty hard do too much mischief to your mandolin.
Thanks for showing me that one, Bill.

[Mike Bromley]

Resourceful indeed!

[Flowerpot]

Whatever you do, be careful that the wheels fit tightly on the posts with no slop in the threads.

I got a Loar-type bridge from First Quality (I believe it was a Sullivan); it looked good, and was cheaper than the Steve Smith. After fitting the bridge, the mandolin never sounded right, and after months of frustrated investigation, I found it was loose fitting thunbwheels, which allowed the saddle to rack back and forth. Replacing the posts and thumbwheels restored the tone.

[JGWoods]

Whew! I'm glad someone else uses a screwdriver. Folks sometimes claim it is butchery to do so, but I've done it for years with no bad results, no marks either if the tool used has rounded corners. I pry so that the blade of the tool is as close a possible to the post on the bridge top, and just enough pry to allow the thumbwheel to turn.

[WindinBoy]

Thanks for this tip

[McCandolin]

thanks for the info all, i'll just get the normal thumbwheels now that i know that little trick. Any endorsements of places to purchase said thumbwheels at?