Steady progress

Shorter legs

Decided the mounting stand height needed to be variable so I cut the legs down to stubs that will later be drilled for bolts so’s I can connect top section to bottom section with three pieces of angle iron. For now it’s at a convenient height for me to carry on, on the workbench.

And yes, I know the pipes aren’t all completely vertical. Once everything else is done and just before I paint the manifold I’ll use a rosebud tip and an oxy-acetylene torch to straighten the offending bits.

Lathe setup

Lathe setup to turn bevels onto lower end of brass ‘bells’. I made good use of my homebrew outfeed support; it has twice the diametral capacity of the unit sold by Myford, which couldn’t accommodate the task.

Tuning Door Assemblies

With bevels cut on all bell bottoms it was time to address the the difficult task of making them tunable for different media, as I want this thing to sound right on air, propane and steam. Taking a tip from friends who tune organs I cut all the brass tubes to a length that is 1″ longer than nominal, then I cut a 1/2″ wide x 1-1/2″ long slot in the tops of each one. I made little sliding doors that can be easily moved up and down to cover more or less of the slots, thus varying the length of the bells. I plan to tune the whistles on compressed air, then scribe marks at the top of each door. A little calculation should give me the relative movements for steam and propane, so that I won’t have to made adjustments on the fly, on hot pipes.

Door Clamp Top View

Originally I had thought that I could use a little piece of threaded bar inside, to fasten the door to the outside of the bell but the thing wouldn’t always seat right. In the end I opted for the ‘manhole cover’ solution with threaded circular disks as in the photo above.

Next up: I’m going to build a plywood air box and affix a surplus muffin fan to one side. I’ll bore a hole in the top so I can drop first one and eventually all 12 whistles on the box for tuning. Photos in a few days.