Saturday, August 13, 2011

mufflers and experimental aircraft

Here is what the reducers start out as-- a solid chunk of 1020 steel. I played around with spinning and swedging these parts, but the tolerances were too loose and they ended up with a very thin cross section at the larger diameters that would have ended up cracking and failing. I have a friend that makes indian mufflers with spun reducers and a few of them cracked at the bell. Machining them out of solid stock is expensive, but it provides a consistent cross section and a predictable and precise part.

here is a picture of the i.d. being bored out.

The next step is to anneal the part. There is a lot of stress going on in the metal from being manufactured and machined. Heating it up to a soft orange glow and slowly cooling it down normalizes and settles all the molecules in the metal. This allows us to crimp the edge of the reducer over the lip of the can with out shearing the metal. We will only use the torch set up on the prototypes. The production reducers will be sent off to the heat treaters to be annealed in a big batch, which is a lot better than doing each one individually

HEre is the proto type can. with reducers installed. I should have a completed prototype muffler sometime this week. I dropped this one and put a small dent in the top of it. I will just fill it up and metal finish it. out. Set up pieces always seem to take a beating. I am very happy with how this is turning out.

We went flying in Delmar's little challenger plane. This is a 1400 cc, two stroke motored plane.

Here is a picture of me next to the challenger for scale. This plane only weighs 400 pounds and can lift it's own weight. Delmar and I put together weigh over 400 pounds. This plane is so cool
It is the most fun that I have ever had flying. You are out in the open and it feels like you are a bird. I need to get a plane.



  2. Hi,
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