The "I hate rework" page

or

"The story of the crooked pipes"

 

I hate rework ... but I had to rework the largest windchest. Here's what happened.

I designed the pipes to sit on wooden dowel feet, which were brought to a point and rested in a countersunk hole in the windchest. The PIPE RACK (that supports the pipes) and the top deck of the windchest were line-bored (drilled together) to get the center-to-center distance of the holes exactly the same. I wanted the pipes to stand straight and parallel. So far, so good. Right?

Then, I chamfered the holes for the pipe feet to rest in. This operation I did freehand, on a drill press. That was a mistake!! You know what happened: the countersink did not always stay in line with the hole, and I ended up with chamfers that were NOT concentric with their holes. The pipes stood each at a slightly different angle, and none of them perfectly vertical.

I should have at least used a piloted countersink ... or, ideally, clamped the pipe and windchest deck in the mill line-bored them and chamfered the deck all at the same time. Live and learn.

In any event, the problem manifested itself in the pipes not all standing straight. If you look at the early pictures of the organ, you might be able to see the misalignment of the pipes.

I fixed the problem by making a new top deck to the windchest, and changing the pipe foot mounting method, as described pictorially below.

 

The pipe feet were modified. The smaller pipes already had 1/2 inch aluminum tubing spool joining the foot to the pipe. Now they would have the same connection method to the wind chest.

Here, I am boring the pipe foot for a tight slip fit to the aluminum tubing. The tubing is glued in place with a urethane glue.

Here's how I got the holes concentric.

To get the 1/2 inch holes absolutely concentric with the pipe rack, I first mounted the pipe rack to the new deck. Then, one at a time, I picked up the center of each hole in the pipe rack as show in the photo. I would adjust the mill table until the sleeve shim would j-u-s-t drop through the hole. Thus, I could be confident that the drill was centered on the hole within a few thousandths of an inch.

Then I removed the sleeve and drilled the hole. Voila!

A coat of Varathane® on the new windchest top deck, mount the new feet on the pipes and I'm done. Of course, I had to re-mount the magnets on the underside of the deck.

The pipes stand VERY straight now -- and, because of the 1/2 inch pipe spools, they don't fall out when I tip the console over. (see below)

 

 

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