TBQ Alessi Trigger Screw Coming out

[BigB]

So I recently got the Shires TBQ Alessi trombone and it’s great, other than the simple fact that there is the screw the spring is attached to, and it doesn’t want to stay in. I have to get a tiny screwdriver, which is hard to find, then screw it in about once a day. Anything that could stop it from coming out?

[GabrielRice]

https://www.loctiteproducts.com/en/prod ... ue242.html

[Crazy4Tbone86]

My experience has been that whenever a trigger “unscrews itself,” the source of the problem is that the screw cylinder (the part of the trigger that the hinge screw goes through) is either too tight or it is out of round. The cylinder is essentially gripping the hinge screw on every back stroke and undoing itself in a counter clockwise motion. The solution is to have a tech adjust the screw/cylinder relationship so that there is no gripping. This is usually a matter of only 1 or 2 thousandths of an inch. If too much is taken out of the cylinder, the trigger will have wiggle on every stroke and have loss of motion (you will press on the lever, but it will not actuate the trigger until it has moved a certain distance).