I would sure be impressed if someone here told me they thought they could build a 1/2a (maybe .061) rotary (wankel) engine. This, I believe, would be a great challenge.

Wink

Wink,

I know I can't but I bet being you have access to the machines that you could! Time to brush up on your gear cutting skills

Later,
Tim

I have no gear cutting skills.... I've never done it. I wouldn't even know where to start on a project like this, but it would be cool.

Wink

I was trying to describe a MAZDA WANKEL to a young fella the other day, and I pointed out that there seems to be less tolerance for imperfection and wear with this design, because they didn't seem to have much longevity. I have seen some SCREAMING examples at the dragstrip, and they were VERY LOUD! At one time there was a CORVETTE concept car with a twin rotor engine. The OS .30 is still around, I think? If a guy could get a high speed WANKEL going for model planes, then that would be the way to match up with the electrics for streamlined cleanliness.

Another type of interesting engine that may be easier to build than a wankel is a 'barrel' engine.
The crankcase is a snap to make, the crankshaft, yeesh..
Here's an example:
[link=http://www.dynacam.com/Product/product.html]dynacam[/link]

How about a 1/2a RCV type engine? Few parts to make. Although the geared cylinder would be a real booger.

i've always thought that a 1/2A wankel would be doable. seems like the problems with seals and heat would pretty much go away with 25% castor.


dave

Is this something you guys think might actually be possible?
I have found all the information on the math involved, and I can figure out an .061 version, and I think I can make the rotor, other than the gears. The crankshaft (eccentric shaft) would be simple to make. I think the housing could be easily machined on a CNC machine, but I wouldn't know how to polish it to a nice enough finish. I think making the housing out of alluminum with some kind of hard coating on the interior would be perfect, but what kind of coating? Maybe just hard anodizing like Norvel uses on it's cylinder wall? Should the rotor be steel like a mazda, or can you get away with alluminum? Maybe you wouldn't need apex seels on something this small with castor oil? Could you find some kind of gear set-up that could be adapted to work, or would you have to cut gears?

Wink