key action mechanics question

[lizny]

I successfully midified my manuals, but it is a bit fragile and I'm reconsidering some of my choice and might go back and re-do things. I made a modular design so swapping things out without a complete rebuild is an option.

One of the things that drove my choices is the original electro-mechanical tripper action. I removed the combination box, but I left the spring-loaded cranks in place. In the photo you can see, the end of the keystick pushes up on a lever which swings the bar over to touch a set of contacts, which I removed.



I left these parts even though they do nothing because of the springs. I was afraid removing it all would make the key touch too light since it was designed to work with them. If I removed them, I could move the Hall sensor array here. Currently it is underneath the keysticks. I could have the magnets set on those convenient bits of metal already there, instead of on the slightly fragile arrangement I have now (every few weeks I've got to get in and fix a bit of magnetic tape come loose).

What do you experienced folks think. Would I regret removing those springs? Could I compensate by tightening the other springs which are screwed into those leather nuts?

Besides getting in the way, it all adds a fair bit of noise to the action. I don't notice at all when I'm playing, but comes out louder than the music if I record on my phone - say if I wanted to work with a remote teacher.

[lizny]

Well I didn't get an answer but did eventually get annoyed enough to go forward and figured out what to do.

Removing the box with the swing-arms and second springs made re-installing the sensor bar to the top a milion times simpler. Wish I'd done it that way in the first place.

Removing the second springs does make the keys too light, but it is easy enough to fix. A little research yielded the information that AGO standard is 3 1/4 ounces, and that keys should sound at the midpoint of travel.

I build myself a little key-weight from some random bits I removed from the organ and fiddled it till it weighed 3.25 oz. That matches the keys on the swell, which I haven't touched yet - it moves the keys down to roughly halfway. Now I can adjust the single remaining springs on the great. The increase I need is more than turning the leather adjustment nuts can reasonably do, but I can fix it at the other end. Just slipping the springs onto their hooks 3-4 turns down the spring, instead of from the end loop, makes them just the right resistance, verified with the test weight. ta-dah.

[lizny]

Epilogue - I decided to replace the springs entirely with new ones. Not cheap, for 2 manuals worth of new springs, and a ton of work, but the results were worth it. The touch feels just wonderful now, smoothly springy and even across the compass.

https://lizvpo.blogspot.com/2020/10/...g-manuals.html

[j reimer]

Yes, Liz, your attention to detail and your readiness to put in the work is truly impressive.

[voet]

Lizny, I am impressed with all you are doing. Thanks for sharing, even if nobody replied to your initial request.