emergency repair #1
Posted: Wed Oct 18, 2023 1:07 pm
Vito bass clarinet...
lost tension screw (unique to bass clarinets, and individually-fit to various makes)
With all of the summer repairs, we used up these parts on all of the Vito bass clarinets sent it whereby these parts had been carelessly lost...and they are asking if we can repair it in a shorter amount of time (and it needed a whole bunch of ACTUAL pad/corks/key regulating work mostly...) than it would take to get these parts (IF ?? in stock anywhere) shipped in.
The odd-shaped head (either this funny rectangle or a pin) secures the screw at a certain angle/orientation. The threads of the screw barely descend into the hollow cylinder - with the part that is inside the cylinder being smooth, yet with a specifically-located and specific depth "quarter moon" ground into it.
When the floor peg is in place, the wingnut (or knob, depending on make) pulls the screw towards the wingnut and puts tension on the floor peg. This allows the floor peg to be tightened in place but WITHOUT marking it all up.
Both the special screw and the wingnut were missing.
I could have swapped complete assemblies, but this bracket is SILVER BRAZED to the lower joint receiver, so we didn't want to get into hacksawing, grinding, filing.
I found a 2-1/2" SAE 1/4 x 20 screw (with a smooth area, before the threads begin) with a hex head. I ground the head down to the specific rectangular size needed (.180" wide), cut the threads off, re-tapped the same thread size down to the point where they would just barely enter the cylinder, eyeballed where the filed away 1/4 moon area needed to be (in the screw, filed it down the correct depth (via measuring by sticking drill bits in there - until I found the one that would not pass and doing the arithmetic), filed the shape, found a metric wing nut, tapped it to 1/4 x 20, installed everything, checked the fit, and then added a solder blob to the end of the screw's threads - so they could not carelessly lose these parts again.
(Somehow, they did not manage to lose the floor peg...??)
I didn't use the lathe, nor the press, nor a mill.
I used a grinding stone/wheel (floor-mounted), a file, a hacksaw, a nail (to mark the center of the quarter moon), a few drill bits (to measure how deep the 1/4 moon shape needed to be), a tap, a die, solder, flux, torch, and the crappy bench calipers. ...The head of the alter screw bears some of the original screw-identifying stamping...I saw no reason to grind off that zinc coating.
lost tension screw (unique to bass clarinets, and individually-fit to various makes)
With all of the summer repairs, we used up these parts on all of the Vito bass clarinets sent it whereby these parts had been carelessly lost...and they are asking if we can repair it in a shorter amount of time (and it needed a whole bunch of ACTUAL pad/corks/key regulating work mostly...) than it would take to get these parts (IF ?? in stock anywhere) shipped in.
The odd-shaped head (either this funny rectangle or a pin) secures the screw at a certain angle/orientation. The threads of the screw barely descend into the hollow cylinder - with the part that is inside the cylinder being smooth, yet with a specifically-located and specific depth "quarter moon" ground into it.
When the floor peg is in place, the wingnut (or knob, depending on make) pulls the screw towards the wingnut and puts tension on the floor peg. This allows the floor peg to be tightened in place but WITHOUT marking it all up.
Both the special screw and the wingnut were missing.
I could have swapped complete assemblies, but this bracket is SILVER BRAZED to the lower joint receiver, so we didn't want to get into hacksawing, grinding, filing.
I found a 2-1/2" SAE 1/4 x 20 screw (with a smooth area, before the threads begin) with a hex head. I ground the head down to the specific rectangular size needed (.180" wide), cut the threads off, re-tapped the same thread size down to the point where they would just barely enter the cylinder, eyeballed where the filed away 1/4 moon area needed to be (in the screw, filed it down the correct depth (via measuring by sticking drill bits in there - until I found the one that would not pass and doing the arithmetic), filed the shape, found a metric wing nut, tapped it to 1/4 x 20, installed everything, checked the fit, and then added a solder blob to the end of the screw's threads - so they could not carelessly lose these parts again.
(Somehow, they did not manage to lose the floor peg...??)
I didn't use the lathe, nor the press, nor a mill.
I used a grinding stone/wheel (floor-mounted), a file, a hacksaw, a nail (to mark the center of the quarter moon), a few drill bits (to measure how deep the 1/4 moon shape needed to be), a tap, a die, solder, flux, torch, and the crappy bench calipers. ...The head of the alter screw bears some of the original screw-identifying stamping...I saw no reason to grind off that zinc coating.