Shortage of wind problem

[profeluisegarcia]

Hello all:
I´m going to repair a french 1909 Merklin 6 stops organ. The blower has 1.5 hp motor, 1700 rpm, and the centrifugal fans are 50 centimeters diameter. The manometer pressure marks 71 mm when fitted to a toe hole.

Theoretically everything is ok, and I don not find what component should I change, but the bellow hardly rises a few millimeters.

The distance from the blower to the bellow (reservoir) is 4 meters and the diameter of the flow tube es 20 centimeters.

The question is: if I made a new flow tube of 30 centimeters diameter and I move the blower 2 meters near the organ, could the pressure be increased?

Any other thought or suggestion will be much appreciated.

Luis
Colombia

[Nutball]

That might help slightly, but are there any air leaks? Is the bellow stiff from sitting unused for so long? Is the motor reaching full speed: does it turn freely when off or do the bearings need oil, is it plugged directly into the wall on a circuit breaker that doesn't share high power appliances, or is it on an extension cord? Maybe turning it on and manually lifting the bellow might help loosen it or help you find the problem especially if it falls back down after letting go with the fan still pumping. I don't know much about working on pipe organs, but these are my ideas.

And make sure the blower intake is clear, no walls blocking it. Make sure the filter is new and clean if it has a filter.

[profeluisegarcia]

¡Thanks to your interesting suggestions. Nutball. I´ll travel tomorrow to the town where the organ is installed to check them.

[nsa66]

I know the thread is now a couple of months old but I wonder how you got on. If you've not made any progress there's one thing that immediately springs to mind. Between the centrifugal blower and the main reservoir (bellows) there is often a wind admission valve (usually a simple sliding gate). This is operated by some sort of linkage (either cable or rods) from the floating top of the reservoir. It is worth checking that this is opening when the bellows is empty. Often the linkage is disturbed, usually as a result of someone using the organ chamber as a handy store room!

[Pipeorganbuilder]

Good point nsa66. The gate valve is often connected with a small chain or a rope. Either one can come loose and let full air into the reservoir. Also, it is not uncommon to find a soft metal used as a fuse link to shut air off in case of a fire. I have had a couple of these links to break. Let us know how things are going with you.

Michael