Sax on the Web Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter #1
Hi, wondering if anyone can suggest what to do here. I have a stuck rod screw on the palm D key on a buescher tru tone alto. One side of the screw remains but the other has corroded away leaving no way of uncrewing with a driver.
 

·
Distinguished Technician & SOTW Columnist. RIP, Yo
Joined
·
17,204 Posts
I would use a dental micromotor with a very small inverted cone bur to make a new slot in the screw without attacking the post.
I would repeatedly smother the area with penetrating fluid such as PB Blaster, and heat the area quite hot, say 150C. Leave overnight and repeat the repeated process.
I would determine whether the stuckedness i within the post or the pivot tube.
I would then use a screw driver specialised for the purpose - a perfect fit, t5op quality steel, with long handle and decent diameter handle.
I would have the experience to know when I have reached the limit of what the metal of the screw can stand, so as not to do further damage to the screw!
If this fails, which is very rare, then I would either
a. Use the micromotor and an inverted cone bur to start a hole, then drill a hole through the steel which remains in the post, then wrench the key up, breaking off the threaded end. Then use the the micromotor to drill a hole through the threaded part, probably about 1.5mm diameter - a short drill with 2.3mm shank for rigidity - then use a pentagonal broach to jam in that threaded part and unscrew it.
or
b. Unsolder the mounting assembly from the sax body and wrench the post from the key-with-rod, etc, etc. Or that failing, use a long hot soak in strong alum solution to dissolve away the steel.

In all cases I would spend about 10 minutes making a new rod from stock metal.

Apart from the micromotor part I think this is pretty standard stuff for technicians.
 

·
Distinguished SOTW Member, Forum Contributor 2016
Joined
·
18,000 Posts
The 'nutshell' here being, due to the fact that both the rod is stuck and the original head slot is shot, a home-job is probably not the best scenario for this one.
 

·
Distinguished SOTW member, musician, technician &
Joined
·
4,983 Posts
One side of the screw remains but the other has corroded away leaving no way of uncrewing with a driver.
The photo shows a slot, why isn't it possible to use it to unscrew with a screwdriver? Maybe it only looks this way but the slot is too short, or is it just brightness difference and it's not there at all (just different reflection on an almost flat surface)?
 

·
Distinguished SOTW Member
TENOR, soprano, alto, baritone
Joined
·
7,444 Posts
Illusion - one side of the slot is broken off. Its a tough problem.
 

·
Distinguished SOTW Member/Technician
Joined
·
4,690 Posts
I am not as patient as everyone else it appears.

I would waste no more than 5-10 minutes on the job, broken screw = drill it out, if you cannot drill it out, then heat and remove key and saddle, splay the posts apart slightly, use a saw and cut through the steel and remove the key and then the broken rod, reshape the saddle / solderback in place and cut new rod.

Steve
 

·
Distinguished Technician & SOTW Columnist. RIP, Yo
Joined
·
17,204 Posts
... One side of the screw remains but the other has corroded away...
Actually that is highly unlikely. One side breaks off when an inexperienced person tries to remove a stuck screw, and or the tools used are not satisfactory.
 

·
Registered
Joined
·
5,482 Posts
Well, first of all, this is NOT a job for the everyday home mechanic (and I think most people could do a lot more repair at home than most people think).

I've faced things like this before and it's a real bear.

How about using the micromotor to make a slot on the other end (the threaded end), and screwing it in to screw it out (assuming you have access)?

I think the original root cause is that the rod has corroded into the post. Everything else has followed from that, so you're going to have to get it looser in the post. (Thus Gordon's points on using penetrating oil and heat, repeatedly.)

I have to say that these little rods are a weak point of the saxophone design. Add to the frequency with which they get corroded and stuck, the fact that the short length doesn't really do a very good job of preventing side to side motion.

I have a bunch of old saxes, many of which are Conns with the little microscopic set screws, and part of my regular lubrication routine is putting a tiny little bit of oil on the tiny set screws and a few other places that are prone to corrosion. The little rod screws' threaded parts will get oil wicked to them if you periodically oil the mechanism; but on an old horn it may have gone years or decades without ever having any oil there.
 

·
Registered
Joined
·
5,482 Posts
Actually that is highly unlikely. One side breaks off when an inexperienced person tries to remove a stuck screw, and or the tools used are not satisfactory.
Agreed. There's probably some rust in there that makes it look like one side rusted off, but it was probably broken off.
 

·
Distinguished SOTW member, musician, technician &
Joined
·
4,983 Posts
If it's an optical illusion and one side of the slot is broken (I didn't understand that by "screw" it meant "slot" in the original post), then I'd do pretty much what Gordon described. Re-slotting in the post (essentially deepening the original slot) has worked for me in probably 99% of cases, with (or sometimes even without) penetrating oil and heat.

I almost never have to resort to drilling out screws, but if you try it, consider that you have to preapre the surface somehow. It's unlikely you can drill the half broken slot, the drill will just slide off of it and likely grab on its side without drilling. You might be able to drill the other side, but that has a bunch of other risks. It's all possible but there are a few thigns to consider before doing it.
 

·
Distinguished SOTW Technician
Joined
·
998 Posts
I pretty much attack this as Gordon suggested, most of the time, because I am stubborn and it's about 50 50 to whether i grind out the rod, or get it to come out by cutting a new slot. I have even gotten lucky a few times taking a piece of drill rod the same diameter are the hinge rod. Then cut a section out of the end so that the remaining portion cradles what is left of the end of your hinge rod. The interior of the post holds the tool in place until it backs the rod out a bit. it is best to harden the rod after making the cut,and this to is about 50/50. usually grinding it out is the easy fix, and fastest. As others have said, best done by skilled hands, it is easy to mess up.
 

·
Banned
Joined
·
566 Posts
broken screw = drill it out, if you cannot drill it out, then heat and remove key and saddle, splay the posts apart slightly, use a saw and cut through the steel and remove the key and then the broken rod, reshape the saddle / solderback in place and cut new rod.
this is the go.
 
1 - 12 of 12 Posts
Top