TromboneChat

Not sure which section to post this in, but having some trouble with my Cerveny Cimbasso. On really hot days (and I don't have AC), the peg / endpin doesn't hold (it is adjustable, and secured entirely by what I think is called a friction fit) and the whole instrument continuously slides down, making it impossible to play. I'm not sure about tightening the screws on the adjuster any tighter as I'm worried this may wear out the threads over time (I just make them to be finger tight.)

Any ideas what could be done here to help with the problem? Is it time to take it to a tech, or is there something (non-damaging) I could try?

Edit: uploaded some pictures!

I think a photograph would be worth a thousand words in this situation. Can you find a way to post a photo?

Over the years, some cello and bass players have come to me with similar "slipping" endpin issues. Similarly, they were concerned about "over torquing" the screw and stripping the threads. On some of them, I was able to put the rod on my lathe and "cut in" the slightest bit (for a section about a 1/2 inch long) at the exact spot that they wanted the screw to grip. It created an indented area that the screw would catch on and there was no more slipping. Of course, this is only possible if the original rod has a large enough diameter that a small indentation would not compromise the integrity of the rod.

A picture would definitely help, to see what the grip situation is. And if you can measure (accurately) the diameter of the rod... I make upright bass endpins, which are mostly 10mm. I'm sure there are ways to create a secure stopping point..

I'm not sure exactly what you're describing but I wonder if something like a collar with a set screw might do the trick if you add it to the peg and use the collar to set the depth you want.

https://www.homedepot.com/p/Climax-1-2- ... /203025022

--Andy in OKC

Hi guys, thanks for taking the time to show some interest. I've uploaded a couple pictures to the original post

As the screws are fastened the ends of the adjuster-cylinder-clamp-thing closes up and grips the peg, but despite the notches on the peg itself, those are only for keeping track of a player's height preference (they do not actually latch into the adjuster to provide any support.) As I understand it, the horn is kept in position entirely by friction battling against gravity.

Maybe afugate's idea would work? If that screw collar was able to tighten strongly enough on the lower half of the peg, just below the adjuster/clamp... and it would be far more expendable than the system welded onto the horn. IDK though, and I'm definitely not very hardware-wise! More of a software guy if I'm to be chatty

That looks like it probably is 10mm. I can make a brass collar with a setscrew for that. I need to make some of those anyway.

Wow.....wing nuts.....just like the old Bach convertible connectors. That is NOT what I was expecting to see!

I like the idea of the brass collar with a set screw. It should hold it firmly in place and be adjustable if the cimbasso were to be used by someone else.

Might be worth putting a rubber bumper or perhaps an O ring or two between the collar and the rest of the horn to minimize damage if the horn is lowered too quickly.

--Andy in OKC

Dumb question: Does the slot between the two halves of the wing nut clamp completely closed? If so the solution may be to widen the slot.

The problem I see with the collar is that you can't leave it in place if the peg has to be stored as shown and then extended later. If you wanted to leave the collar preset for your playing position you'd need to carry the post separately and insert as part of your setup.

Good point Bruce. That was a problem with a lot of the Bach convertible bell connectors and the old Bach removable leadpipe system.

I still think it is best to go with a brass collar. Those wing nut connectors really don't hold heavier objects very well. The OP is justified in being concerned about putting too much pressure on them to make it tight. I have seen several of those tear at the base of those cylinders that hold the threaded part. I had a convertible Bach 42 in the 1990s in which both of the wing nut cylinders tore at that spot.

A light coat of paint on the rod, or maybe nail polish, would give it more friction.

Doug Elliott wrote: ↑Sun Aug 15, 2021 8:27 am That looks like it probably is 10mm. I can make a brass collar with a setscrew for that. I need to make some of those anyway.

If you're offering to make me one, that would be great! I tried one from a local hardware store, and ran into a problem (picture attached. There was not enough space for the shaft collar to slide up, as it collided with the C valve.) It does seem like the idea would work though, as once it was screwed in there, it would've taken quite a lot of force to make it slide.

The peg measures around 14mm diameter.

BGuttman wrote: ↑Sun Aug 15, 2021 2:14 pm Dumb question: Does the slot between the two halves of the wing nut clamp completely closed? If so the solution may be to widen the slot.

The problem I see with the collar is that you can't leave it in place if the peg has to be stored as shown and then extended later. If you wanted to leave the collar preset for your playing position you'd need to carry the post separately and insert as part of your setup.

The slot does completely close up, yes. And you're right about the setup, it would require moving the collar around a lot, which wouldn't be ideal, but might be tolerable

14mm is huge for something like that. If the rod is solid it must weigh a lot.

I would need some detailed measurements, but a much better solution in my view, what I would do, would be Lexan sleeves at the clamp points, with a smaller 10mm rod. There would be more friction so it wouldn't slip, and you wouldn't need a collar.

Doug Elliott wrote: ↑Mon Aug 16, 2021 1:00 pm 14mm is huge for something like that. If the rod is solid it must weigh a lot.

I would need some detailed measurements, but a much better solution in my view, what I would do, would be Lexan sleeves at the clamp points, with a smaller 10mm rod. There would be more friction so it wouldn't slip, and you wouldn't need a collar.

It does weigh a ton, as much as, if not more than, the fully built horn

I'm not sure what Lexan sleeves are, but it sounds like stuff that a pro tech would have to do anyways. Don't know if I'd trust my local Long&McQuade (Canadian music store) technicians with that kind of job, but I could bring it to them and get them to assess the situation anyways.

I built one of Ken Lee's cantilever ergobone supports.

I used a conduit hanger like a hose clamp to connect to the receiver, but it slipped and I didn't want to tighten too much and maybe damage the horn.

So what worked was to wrap a one layer of a thin piece of rubber around the receiver first. I had a good bit of very thin rubber from an exercise band set that people use for rehab. It worked very well. I tried masking tape first but that was ever more slippery than the brass. If you didn't have that handy, I would think maybe a piece of a balloon or a latex glove might be about the same.

timothy42b wrote: ↑Mon Aug 16, 2021 2:04 pm I built one of Ken Lee's cantilever ergobone supports.

I used a conduit hanger like a hose clamp to connect to the receiver, but it slipped and I didn't want to tighten too much and maybe damage the horn.

So what worked was to wrap a one layer of a thin piece of rubber around the receiver first. I had a good bit of very thin rubber from an exercise band set that people use for rehab. It worked very well. I tried masking tape first but that was ever more slippery than the brass. If you didn't have that handy, I would think maybe a piece of a balloon or a latex glove might be about the same.

Worth a shot, just might do it

No problem for me to make what I'm talking about. I do that sort of thing all the time. I do need good measurements.

Doug Elliott wrote: ↑Mon Aug 16, 2021 6:41 pm No problem for me to make what I'm talking about. I do that sort of thing all the time. I do need good measurements.

Thanks for the offer; what kind of measurements would you need?

I also am wondering if a 10mm peg would have enough support. Maybe Cerveny had a reason for going with their massive 14mm one, as the horn does stand at a slight angle, and it's noticeably larger than a normal Cimbasso (much bigger bell.) Could it be they thought extra support was appropriate? I'd think an even thinner peg would be even more prone to bending.

Measurements I would want:

Actual diameter of the rod, measured with calipers or micrometer. Is it loose in there? You say the slots close down all the way when the clamps are tightened? - so maybe the rod could be slightly bigger to be a better fit, and the clamps would hold better. You probably don't have a good way to measure the inside of the tube.

Length - total length of the rod. How far does it extend past the bottom clamp when in playing position?

Length of the tube - clamped section, top to bottom. Length of the clamps themselves, the slot area.

There's one really easy solution, that I use on music stands - a hose clamp. You can get them with a wing handle to tighten by hand. They're hard to find but I have some and I can send you one.

Where are you? In the US or not?

Doug Elliott wrote: ↑Tue Aug 17, 2021 8:34 am Measurements I would want:

Actual diameter of the rod, measured with calipers or micrometer. Is it loose in there? You say the slots close down all the way when the clamps are tightened? - so maybe the rod could be slightly bigger to be a better fit, and the clamps would hold better. You probably don't have a good way to measure the inside of the tube.

Length - total length of the rod. How far does it extend past the bottom clamp when in playing position?

Length of the tube - clamped section, top to bottom. Length of the clamps themselves, the slot area.

There's one really easy solution, that I use on music stands - a hose clamp. You can get them with a wing handle to tighten by hand. They're hard to find but I have some and I can send you one.

Where are you? In the US or not?

I'm located in Canada; Kingston, Ontario. I'll see if I can get some precise measurements.
Apparently the hardware store around here should be carrying some hose clamps so I'll take a look around.

Regarding the looseness of the clamped section; it's quite a tight fit, there's no wiggle room and there's a mild amount of resistance when nothing is tightened down. The slots indeed close down all the way at the ends.

Doug Elliott wrote: ↑Tue Aug 17, 2021 8:34 am
There's one really easy solution, that I use on music stands - a hose clamp. You can get them with a wing handle to tighten by hand. They're hard to find but I have some and I can send you one.

This seems like a simple solution.
--Andy in OKC

PM me your address and I'll send you one of those hose clamps. You probably won't find the wing kind locally.

Doug Elliott wrote: ↑Wed Aug 18, 2021 7:27 am PM me your address and I'll send you one of those hose clamps. You probably won't find the wing kind locally.

Will do, thanks Doug

Past couple of days were really hot again; felt like 40 c with humidity.

Crisis breeds innovation, so I present to you my patented 'strip of masking tape ®' solution which seems to work remarkably well considering how pathetic it looks. (Inspired by suggestions here of using thin strips of rubber or a light coating of paint; just something to add a bit more to the peg.)

I initially tried wrapping the clamped area completely around with the tape, but that proved to be too much and I couldn't get it back on the horn; a single strip running vertically over the area clamped, covering roughly half the peg in width, seems to have added just enough extra material and grit to create more friction and a better clamp. Seems to be working for now

Tremozl wrote: ↑Mon Aug 23, 2021 8:59 am Crisis breeds innovation, so I present to you my patented 'strip of masking tape ®' solution which seems to work remarkably well considering how pathetic it looks. (Inspired by suggestions here of using thin strips of rubber or a light coating of paint; just something to add a bit more to the peg.)

Slick! (ummm or not, in this case! )

--Andy in OKC

When you finally decide where it must stop, mark it with a sharpie and have your repair guy make a brass stop collar out of round stock that clears that slide and soft solder it in place.
I've done a few of these.
Don't be afraid of making it semi-permanent.