Rotary valve clatter

[jeopardymaster]

An open question to the "Jury" - what process(es) do you follow to address valve clatter? Mine traditionally has been to take the horn to a pro, something I can afford to do only so often. How about you guys? What do you address first? Anyone care to volunteer some of their acquired expertise?

[eupher61]

Not to second-guess bloke, but I will anyway.

Is the noise from the ROTOR or the LINKAGE?? Big difference.

[Michael Bush]

So play is the problem, and more play is the solution?

(Not that this would surprise me at all -- I'm very used to paradoxical solutions -- just making sure I understand...)

[eupher61]

Talley, i don't think that's what bloke was saying...shaving the bearing plate down would tighten things up a bit.

[Michael Bush]

...which is why I asked... Thanks.

[iiipopes]

3-N-1 oil the linkage.

[sethbrown]

Try using Hetmann's #12 oil on the rotor itself. I will put some on the back of the rotor on my horn and it works like a charm.

[iiipopes]

Sewing machine oil on the upper spindle bearing and in the well of the rotor cap. Pull the valve slide without fingering the valve to create vacuum to draw the oil into the rotor bearings (obviously doesn't work on vented valves).

Renew the rotor arm bumpers to make sure the rotors are not over-rotating and catching or binding the linkage.

[DHMTuba]

Just an idea - check the plate that holds the bumpers (don't know the correct name for it). Just last week I was chasing down a noise and discovered that the screws attaching that plate to the valve body were loose. Every time the rotor stop arm hit the bumper the plate would move and go "clunk".
The noise took forever to chase down but it was easy to fix. Snugging up the screws (I gave them a tiny dab of blue threadlocker for good measure) sorted it out. HTH.

[jeopardymaster]

3-in-1 Oil goes on my horn now and then but I will start putting some on the bottom post to see what that does. But I have minimal skills in the metalworking department, so I ain't shavin' nuthin.'

[mdbtuba]

Definitely check the linkage first, and try the thicker oils. But if they don't work, I would never think of doing any actual shaving down of anything, as I would most likely screw it up.

I'll often have the same issue after I give the horn a bath. For me, it's typically that the valve is not seated perfectly with the plate on the bottom of the valve (that holds the bottom of the valve in place so the valve is perfectly centered and will turn easily).

I took a sewing thread spindle (wooden one - older style), drilled a bigger hole in the middle so that the bottom of the valve sits inside the hole, and use that to help me lightly tap the rotor plate (not the rotor) back in place with a rawhide mallet. It needs to stay perfectly even, or the plate will prevent the rotor from moving.

If the plate is in too far, it prevents even and free motion of the rotor. If it is out too far, it will allow movement up and down (in addition to the rotation that should occur), which is where the vast majority of the noise tends to occur.

It's a very fine line as to where the plate should be, but very satisfying when you figure it out.

Hope it helps...

[MaryAnn]

Just an idea - check the plate that holds the bumpers (don't know the correct name for it). Just last week I was chasing down a noise and discovered that the screws attaching that plate to the valve body were loose. Every time the rotor stop arm hit the bumper the plate would move and go "clunk".
The noise took forever to chase down but it was easy to fix. Snugging up the screws (I gave them a tiny dab of blue threadlocker for good measure) sorted it out. HTH.

Yes, I know someone who stopped truly awful noise in just this way, in about five minutes, on a Rudolf Meinl CC.

MA