Question about Removing the percussion unit.

Hi

As winter is again coming and humidity gets lower it's time to make adjustments for instruments. Lately I have noticed that percussion mechanism is causing notes to stuck (stops 1&2) specially at top end of keyboard and I thought to clean and adjust system. I thought to ask if there is something to look after and be aware when removing whole unit. Assuming it is just removing screws (if not rusted) and carefully take out whole system. But as always I might be totally wrong. I someone could share tips it would be helpful.

Best Regards Jaakko

As far as I know, it's just necessary to remove the bars that hold the hammers when the chest is closed.
Nothing else should interfere.
The old leather is often a problem, as it sticks, and sometimes the chest himself going through wood drying, makes the removal a bit difficult.
But nothing else, as far as I see...

Good luck !

Hi Mathieu

I was able to remove whole unit. It was quite tight to get out, but finally it was on the table without damage. And one screw was rusted, but it wasn't problem.
Seems that I'm going to make total overhaul to mechanism including new springs and felts. It is bit too sensitive to climate changes what annoys me a lot. Some of the springs have been changed so to make feel of percussion even thru keyboard so why not to change springs at same time.
Well if it works during 25% humidity/winter then it might not work during summer.
At same time I noticed that there is some work to do with pallet timbre, some cracks have appeared to Cor Anglais bass end.

Was it you Mathieu who participated to  Dib's Mustel repair at Louis shop or have I misunderstood totally? Percussion of that instrument was redone totally I think.

BR, Jaakko

Yes, I actualliy remade al the springs on the percussion of Dib's Mustel.
It's a long and tedious work.
I know Dominique Lavabre did the same recently on an Alexandre.

That's what I also thought, it's going to be time consuming process. I was thinking if piano hammer butt springs or damper springs could be used as starting point and modify those a bit to make right length and curve. Price of 100 is not too much ~10€, but is the force going to be same as original that is the question.
But if it is done right at once it will last my life time.  Well I have time winter is long + dark = cold and nothing can be done outside so indoors harmonium repair is OK.
I found once guide from web how to adjust percussion, but can't find it anymore so it will be more like trial and error. Das Harmonium book it is shortly described.
If some one has instructions I would appreciate those.

Well, Keith Jarrett proposed to use such piano springs for this purpose. But if they are ok, they are not really close to the original ones. Plus I'm unsure about the metal they are made of.
Making them anew will take two or three days of work, plus some experimentation before, but the result really worth it.

Spring material is either brass or standard piano wire in these ready made springs. I'm more concerned about force and long term functionality. Difference is amount of turns and perhaps radius of loop.

Yes it is. I sent you a private message...