Double Bass Adjuster screw thread question

[wayne holmes]

I should clarify- I leave a space just wide enough to see light through ---it doesn't take long, probably a few days till there is no space once everything settles. Then, there is no space but the wheels are still easier to turn-I used to intall them with a void, but like the micro space that becomes no space method better. One thing that I have always wondered about is why it is recommended that some thread be showing. I realize that there needs to be some so the wheels can be turned into the feet(down installation)so the bridge can be lowered. Some say that a couple of turns out with the thread showing a few mms helps vibration also. If this is true, can anyone explain-please.
After saying all this - I really think that no adjusters, period,
produces the best vibration. I have to admit that I installed my first adjusters on my first carved bass many years ago just because they looked cool.

 

[arnoldschnitzer]

I am not married to these spaces and no void in the legs and I am open to anything that improves the vibration. Maybe others have opinions on this.

A certain shop in the NY area (and another out west) installs their adjusters with a space between the wheel and the bridge top. The threads face downward. So, the transmission of energy passes only through a small bearing surface at the top of the shaft. (Sometimes I find a wad of teflon tape in there.) Intuitively, this seems like a bad idea to me. I like the bridge top to make excellent contact with the adjuster wheel, and fitting this part takes a good amount of time. Sure, an adjuster may occasionally get stuck, but that's a minor nuisance. I have altered the adjusters on many of those top-bearing bridges, to ride effectively on the wheel, and in each case the player felt their instrument became more responsive. Perhaps this was power of suggestion, but I don't think so.