Hey Everyone,
Sorry for the long over due build update. My only excuse is I've been working a lot of long and late hours for the last two weeks and have been too tired to spend time on the computer. Tonight is the first night that I've managed to get home from the shop at a decent hour (before midnight) so I thought I should take some photos of what progress has been happening with the engine.
The crankshaft that has appeared in the previous photos was temporarily borrowed from a Heron engine. Last week we finally made the correct stainless steel crank discs, crank throw pins and crankshaft. The next parts that were made were the bronze trunnion spring bushings and the bronze piston rod big ends. After those parts were completed, work finally began on the stainless steel piston rods and cylinder trunnion shafts. The stainless steel crankshaft, throw pins, cylinder trunnions and piston rods were all center-less ground to final size to both ensure consistent diameter tolerances within .0002" and also to ensure a high quality smooth surface finish. This is important since the piston rods would be in linear contact with the lower cylinder cover o-rings and the cylinder trunnion shafts would be in rotationally pivoting in the engine frame. Rough surface finishes on these parts would have prematurely worn the other engine components that came in contact with them.
The next parts that needed to be made were the brass hex nuts which thread onto the trunnion shafts. I decided to make these instead of buying them since all the hex nuts that I could find out there that were readily available were all either too big too thin or basically just plain ugly. I could have just purchased the ugly ones and called it a day but I've grown rather fond of beating my head against the wall these days.
I decided to paint a couple of the engines in the burgundy color that we use on the Sparrow engines. Please, I would like to hear your feedback on what you all think of the Cirrus engines painted in this color opposed to the blue. Depending on all your feedback the engines are going to be painted and offered in one of those colors not both since we do all the painting in large batches.
I'm still experimenting with a couple of the smaller parts on this engine, namely the throttle/directional valve retaining apparatus. Originally I was going to use a simple spring to apply pressure to the valve holding it to the port face but decide to use a more compact arrangement as what you see in the previous photos. This design uses a compressed o-ring sandwiched between the back of the valve and the guide bushing, but I'm not 100% sold on the design yet which is why I'm still experimenting with it. Now that pretty all the parts are completed for the engine to run besides the components that go into the mystery mounting hole next to the crankshaft I decide to shift my attention temporarily back over to the boiler project. The boiler received new upper and lower sight glass fittings which I think are more in-scale with the size of the boiler. I modeled these fittings after larger fittings used on some of our full sized boilers. The boiler also received the final compact burner design which tucks neatly under the engine's intake/exhaust manifold. Every effort has been taken to keep this steam plant as light weight and compact as possible. The total weight for the steam plant so far with the completed engine and boiler including the mounting base is 46.5 ounces.
P.S. BTW, Those are not blemishes in the paint on the engine photos. I didn't realize how much dust was clinging to the engine and various other parts during the taking of the photos till after I put the camera away and started looking at the pictures. Sorry.
Hi Kno3,
Yup you are correct, the lubricator manifold can be reversed if needed.
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Topic: The birth of the Cirrus V-Twin (Read 26287 times)