Cole's Hot Air Betsy

[Raydar]

was digging through my tool box the other day and found parts I had started in making Sterling engine from a set of two prints from Cole's for the Hot Air Betsy. Then as luck wood have it there was the set of prints for that engine, it was karma. Now I'm back on the road to manufacturing the engine from scratch. Has anyone built this engine, if so how did it run?

 

[idahoan]

I haven't built it but I do have it mostly modeled in Alibre Design. I purchased the castings a drawings off eBay some years ago and played around with modeling it. I have made some changes on the mounting of the cylinder and main bearing supports. I didn't really care for the stand offs on the original design. I'm guessing that it was a proven design and should run.

Dave

 

[Raydar]

I haven't built it but I do have it mostly modeled in Alibre Design. I purchased the castings a drawings off eBay some years ago and played around with modeling it. I have made some changes on the mounting of the cylinder and main bearing supports. I didn't really care for the stand offs on the original design. I'm guessing that it was a proven design and should run.

Dave

Thanks Dave. Since I don't have the castings I have looked at changing the design of the cylinder base as I don't like the stand offs either. I just finished roughing out the cylinder base, I may make a spacer the same size as the cylinder base instead of the stand offs. The only thing that made me question not using the standoffs is that I expect the heat transfer from the block to the base to differ without the free flow of air around the bottom of the cylinder base, not sure how that will effect the operation as I'm new to sterling engine design and construction. I'll probably make it with the stand offs and then if the mood strikes me I can make another cylinder base that is just taller, thus eliminating the spacers.

 

[Raydar]

I don't know about everybody else but I do my best thinking when I should be sleeping at night... I may just make the cylinder base out of one piece of brass and make it 1/2" thick negating the need for standoffs, I'll have to see what I have for materials. I'm still wondering if there may be some repercussions by not allowing free air flow around the cylinder block, and the entire base acting as a heat sink. Just thinking out loud I guess. Even though I have already started this project I may start a build thread to show the progress. I am sure that my build will be quite mild compared to what I have perused on this forum.

 

[idahoan]

I don't have any hard data to to say either way but my personal feeling is the solid base shouldn't make any difference in weather it runs or not.
I will be interested in seeing your build.

Dave

 

[Raydar]

Well, I guess I'll start a build thread in the "A work in progress" for the Hot Air Betsy. I'm really new to this forum posting so we'll see how it goes.