Photos
Mike's Workshop Notebook
These castings came from David Moore, (dmprototypes.com) and are designed to operate either manually or by steam. In this build, I plan to refine several areas to improve functionality and adjustability. The spring holder will be lengthened to accept a longer spring, which should make fine adjustment smoother and provide a wider, more practical operating range.
I also intend to revise the cylinder cover bolt circles to improve clearance. In addition, the manual arm detents will be cut deeper to provide more positive, tactile engagement. These changes should enhance both the usability and overall mechanical feel of the assembly while preserving the integrity of the original design.
The real challenge in this project was the mechanism itself. It consisted of three separate components that had to be silver soldered together at specific compound angles. Once soldered, the assembly needed to slip onto a shaft, so maintaining perfect concentric alignment during the soldering process was critical.
Knowing that aluminum will not accept silver solder, I machined an aluminum fixture to hold the parts in precise alignment during soldering. The fixture kept everything concentric and stable while allowing the solder joints to flow properly — a simple solution that made an otherwise tricky assembly both accurate and repeatable.