Twelve string tuners that really work can be challenging. About the only options are individual Waverlys, Grovers or Schallers. To make them work, a lot of times you have to cut near the mounting holes, grind each plate down to "half a hole" on each side and screw 'em all down. The best you can do for 6 on a plate seem to be the German replicas (I forget the name) at $300+, or $1K for Alissi's. Most of us settle for the Stew-Mac vintage.
After thinking about it for a while, and some guessing and hope, I came up with these. They are built from 2 sets of Grover Stay-Tites and 2 sets of Grover 309 F-style mandolin tuners.
Basically, the two sets of mandolin plates are cut as shown, and the gears, worms and string posts are stripped from the Stay- Tites. I just cut the plates with a hack saw and ground them down on my 12" disc sander. Seems I ordered the wrong mandolin tuners as they have worm top and worm bottom, but it works out well anyway as I am trying to make the peghead as short as possible for the 12 string MJ, and didn't want the worm/button too high on the P/H. The joint is nearly invisible, and you end up with an 18 to 1 set of very smooth working gears for $160. Only two drawbacks are the buttons are pretty close, and the post spacing is about .016" off the SM vintage specs.
