Hi Guys
Time for an update on the Kyko project, I have made pretty good progress on both the power and displacer pistons.
The JB Weld has been sanded out and I’m pleased with the results. The power cylinder covers were matched to the casting before they were bonded in place. Hopefully when painted the cylinder casting will appear to be one piece like it was on the original engine.
Next up was to get going on the power piston rod assembly. I chose to machine the big end from solid rather than soldering a bunch of small bits together. Like on the other parts that hold a bearing a lubricator boss was added to this part to better match the original, each boss will get a small knurled grease cup. In this photo the first side is machined, might as well do them both at the same time.
Then the part was flipped over and the other side machined.
The bores for the ball bearings were finished with a boring head.
Here the bulk of the frame was removed to allow access to other features of the part.
The holes for the camp screws were added along with the spot face for the screw head.
Over to the UPT the bottom half of the holes were tapped.
Then the rod end was split using a saw, also you can see that I have finished the bore where the rod screws in as well as the boss for the grease cup. I guess I didn’t do a very good job in the picture taking department.
Here is the completed rod assembly, I didn’t take any photos of the machining but it is all pretty standard stuff.
Here is a slightly different view, the brass round head is temporary and will be replaced with shop made hardware to match the other machined hardware on the engine.
Moving on to the power piston, I chose to use graphite for its self lubricating qualities. The pistons were roughed out leaving the outside oversized to be finished later. I did turn them to a standard collet size, (1 1/6”).
Here the pistons have been flipped around, faced and the hole for the retaining screw drilled and countersunk.
A snug fitting mandrel was turned from Delrin AF to allow the OD of the piston to be finished.
Now on to the displacer pistons, starting with solid aluminum stock the inside was drilled and bored leaving a nice flat bottom hole. I didn’t photo it, after boring the part was flipped around and faced to length leaving a .02” wall thickness at the bottom, the sides will also be this thin.
A mandrel was turned from brass to hold the tube for further machining.
Here the tube has been slid onto the mandrel and a pressure piece added between the tube bottom and live center.
The piston was then carefully machined to the final size.
The caps were roughed out in the lathe and then to reduce weight trepanned using the mill. This was quicker and easier than grinding a cutter for the lathe.
Here are the parts ready for assembly using Loctite.
After the Loctite cured, the pistons were carefully returned to the lathe where they were faced to length and tapped for the rod.
Here is a shot of the finished piston assemblies. They weigh in a whopping 17 grams including the rod. The aluminum parts by themselves only weigh 12 grams. The plans suggested silver soldered brass which would be quite a bit heavier than the aluminum, close to 4X so I think the aluminum will be a better choice both thermal and mass reasons.
Thanks for stopping by, more later.
Dave
