Windchest Part 4:
Testing


After I planted all the pipes and turned the blower on, there were ciphers all over the place.  I was expecting this.  Even though I cleaned all the parts as thoroughly as possible, there were still bits of sawdust in there and it doesn’t take much to create a cipher.  I unscrewed each port to blow it out.  That took care of them all.  I went to the console and played each note a few times and that created several more ciphers.  (Yes, I also finished rebuilding the keyboards this winter- I need to write about that yet)  Most of these new ciphers were fixed again by opening the port to blow it out.

One stubborn cipher wasn't so easy.  I started looking for the most obvious causes and getting more drastic as needed.  First, I inspected the electrical relays to make sure the contact wasn’t bent, or a scrap of wire hadn’t fallen in, making contact.  Everything looked normal.  I confirmed this by unplugging the rectifier, but leaving the blower on.  The cipher continued, so I knew it wasn’t electrical and had to be a problem in the chest.  I thought the gasket around the side board boring may have been damaged and air was leaking out that way.  Nothing obvious.  Next, I gently inserted a narrow dowel into a properly working toe hole to feel the resistance of the pouch.  I tested the cipher and felt pretty much the same resistance, so I knew the pallet wasn’t wide open.  Air was just barely leaking past the pallet so I knew the problem was either with the pallet itself, the leather, the spring, or the toe board.

I took that section of the chest apart.  With the bottom board off I double-checked the gasket to be sure it wasn’t damaged.  It was fine.  Then I took the manifolds out, as well as the pouch board.  Everything looked OK at first- the toe board was smooth and the pallet was clean.  When I pressed down on the pallet with my finger there was noticeably less resistance than other pallets.  The pallet also didn’t sit level when it was “at rest” in the up position.  The leather didn’t feel too loose or too tight on either side, so I suspected the spring.  I removed the paper cover.  Several extra coils of spring were sitting down in the wooden seat.  I gently removed the spring and compared it to an extra spring that was left over.  The offending spring was about 3/8” inch shorter than the spare and was slightly curved too.  I hadn't noticed this when I was putting the springs in initially.  I checked the seat in the pouch board for splinters that the spring could have been snagging on.  Nothing.  So, I put the new spring in & replaced the paper cover.  The pallet was now level and gave the same resistance as the others.

Optimistic, I put everything back together and fired it up.  Silence.  I played the problem note.  It sounded.  I released the key.  Silence!  It was a bad spring after all.  Yes, it was a pain to tear it all apart, but at least I didn’t need to lay a new pouch; it was a relatively easy fix.  The Rohrflöte is painfully out of tune, but the Hook & Hastings Dulciana (which will be my String Celeste) isn’t too bad.  Even though the 8’ octave isn’t hooked up yet, I couldn’t resist the temptation to play a few verses of a couple hymns.  But, it just made me realize how rusty I am!  I need to finish building this thing so I can actually practice!