Saturday, July 14, 2007

Treadle pump as of July 12

The pump has been rebuilt again. I think this is the fifth time. Fortunately, it's starting to look a lot more practical. At least I think so. This iteration incorporates some new features I have talked about in earlier posts, and some I haven't.

The seals, which are sticking out in front of the cylinders to dry are molded using melted paraffin. The pump cylinders have new homemade check valves. The valves are installed both on the same side of the cylinders, which allowed us to reduce the amount of plumbing required, and simplified the routing. The plywood braces have been cut down, to minimize weight and save materials. A cleat has been added on the left end of the pump, to act as a treadle stop, and keep the treadles from beating the plywood brace on the end of the pump to bits. A lot of the extra holes have diasappeared. We needed them earlier so we could change the position of things easily. The design has firmed up now to the point that those adjustments are not needed any more. One last feature that was Jim's idea was to mount the mast with metal loops that allow it to be raised and lowered without tools or any hardware. That's the mast lying across the top of the pump. If you look closely, you can see the metal bails that it slides through. The one on the left rotates with the mast to a vertical position, and allows the mast to slide down and seat on a bracket between the pump bases that you can't see, but is there. In the lowered position, the mast projects past the vertical supports and provides a carry handle on each end. How handy. More tests coming soon.

No comments: