Welcome aboard George. I think you'll enjoy this board.
I've been a bit busy with the project and the photos suffered for it. I'll try to do a bit better as I go along. With the flywheel only needing a bit of polishing, I moved on to the redesigning the cam linkage, which is one of the gizmos that makes all the other goodies work together. It's job is to hold the exhaust valve open until the RPMs drop enough to require another power stroke. At that time it allows the exhaust valve to close, creating enough vacuum to draw fresh fuel into the cylinder chamber.
The original design called for a single rod which slid within a pair of brackets attached to the outer wall of the cylinder. Since I'm in for a penny, I figured to go for a pound and add a bit of complexity to the visual aspect of the linkage. It still operates just as the original design would, but with a little variation on the look of the mechanism.
Two more small parts will still have to be made to complete this section of the build.
Here you can see the cam roller which runs inside the spoked gear. It is made of hardened drill rod to allow it to take the pnishment of beating against the slope of the cam lobe, also located inside the gear ring.
From there I made a quick jump over to the carb, while I sorted out how I wanted to go about completing the linkage assembly. The carb is a simple aspiration type which atomizes gasoline while mixing it with air in the proper ratio for efficient burning. This one does it by use of a tiny #60 drill hole and a darning needle for metering the flow of fuel.
The hard part was drilling a #60 hole 5/8 inch to mate up with the needle's location. Luckily, I had access to a sensitive drill chuck which made things a bit easier to control. Remember.... #60 is the smallest drill in the standard drill index many of us have and brass has a tendency to grab a bit and either break it off in the work piece or drag it deeper into the material than wanted.
Thje length was dicated by Duclos to allow the fuel droplets and air to have time to mix well before entering the combustion chamber. The ball cut and the wide flare on the end were added as a bit of whimsy.
The next direction, while still cogitating the linkage's last steps, was to tackle the exhaust section. Duclos had a nice design and I almost went with it, had I not attended a large show where hundreds of hit and miss engines were on display. After seeing the variety of different styles, I came up with something original, while keeping to totally functional as a muffler. Unfortunately, I did not get any photos before I press fitted the top into the canister.
The exhaust brass stack was the reason for the redesign. I simply wanted to have the vertical stack in hopes that this engine might be capable of blowing the classic smoke rings that hit and miss engines are famous for.
Here you can see all the items together. The little engine is becoming rather complex looking, but I enjoy all the wonkiness of exposed mechanical devices, so this one suits my tastes just fine.
I'm sorry for the longer dleays in posting these photos, but these small parts often take more time than the larger more dramatic pieces. Hang in there and I'll post more in a few days. There are still about a dozen pieces to build and fit, so the saga continues, even if at a somewhat slower pace.
Steve
