The square ones sorta work OK if the slide ferrule is thick-walled.
Otherwise, they get pushed up on to the ferrule just like all of the others.
This is the #1 slide on my Miraphone 98. The o.d. of this tube is probably over 22mm, and the thickness of the ferrule (connecting the slide tube to the slide bow) is probably only about .5mm (c. .020") Particularly since ferrule edges get rounded off in the buffing room (in addition to not being very thick at all), they're not particularly good at supporting something, and preventing it (particularly not rubber) from being pushed up on to them.
Beginning a few years ago, I've bought these TINY gauge of rubber and TINY circle diameter (perhaps 3/8") O-rings for slides.
I have to S-T-R-E-T-C-H the crap out of them (it hurts!) to get them on to a slide (particularly on tubing THIS friggin' large), but
- they DON'T get pushed over on to the ferrules (no matter HOW hard they're banged on), and
- they DON'T suck up any tuning range (because they're so friggin' skinny - possibly only 1mm thick, and then S-T-R-E-T-C-H-E-D out a good bit less than that...I didn't even bother to read what it said on the pkg.)
These were 15 cents each, because I bought them at our "country" (patched wooden floor, wood stove) hardware store, behind the courthouse.
' disagree that these are far-and-beyond the best for this application...??
Keep on a-doin' what you're doin'.
again: You had better have STRONG fingers. (You gym-work-out-monkeys aren't going to be strong enough to get these on, unless you work out on some sort of "finger-reps" machine, and do tens of thousands of reps.) Mrs. bloke didn't think that I would be able to get them to go on... That having been said, I cheated and had her hold the slide for me.
