fan blade direction

Boot · Mar 27, 2011

I'm building one of Jerry Howell's Stirling engine fans and I would like to know in what direction do you put the fan blades in the hub. Is the curvature in this direction to the front of the hub ) or is it facing ( this way when looking at the front of the hub. Hope you can understand. I'll take pictures tomorrow if not understood by anyone. I want to drill the pin holes in them facing the right direction.

Thanks Boot.

Kermit · Mar 27, 2011

a picture is worth one thousand words.

Boot · Mar 28, 2011

Yes and I believe I get the picture. The cupped part must face the front of the hub. Hub front )))))))) cupped this way. ))))What program do you use to make a drawing on line like you did for me?

b.lindsey · Mar 28, 2011

Here is the way mine looks from the front. This is the smaller of Jerry's two fans though and the blades are only angled, not cupped. At least that's the way I did it. Looking at it from the front the blades spin clockwise and the airflow is towards the front of the fan.

Bill

doc1955 · Mar 28, 2011

Here is a link to my build.
http://www.homemodelenginemachinist.com/index.php?topic=9573.msg125946#msg125946
I too thought about forming the blades so I put one together without forming (just flat) and I liked the look so thats what I went with. Works just fine that way and will move a substantial amout of air.

Boot · Mar 28, 2011

I'd like to thank everyone for their explanations on the way the blades should face the front of the hub. It's interesting that Jerry didn't include that in the build plans. Of course maybe he didn't consider someone as dumb as me building one.

Thanks again , Boot

doc1955 · Mar 28, 2011

You know you can run them in either direction. If you look close at the pair I built one runs cw the other ccw. It all depends on the setting of the displacer.

Boot · Mar 29, 2011

Thanks Doc. I didn't know you could configure them to run in either direction. I'll keep that in mind when I assemble it. Right now I need some 1.125+ stainless steel for the cranks. I guess I'll search the scrap yard again. If I had continued to work for Dorr-Oliver Inc. in Hazleton, PA I could of and did have lots of their offal. I took a ton and a half to the scrap yard when I gave up machining as a hobby and went on to photography. I sold my old lathe and gave away an old Brainard mill. Now I'm back into machining and haven't any stock material. How ones hobbies change over a lifetime. Dorr-Oliver was the greatest company in the world to work for. We were bought out by a Canadian company and it went bankrupt up there. I was happy to hear that. I was the last machinist working in Hazleton and we were still operating in the black for them. If only they would have continued to operate in Hazleton the company would still be going. Thank God for our union I get a good pension from the International Association of Machinists and Aerospace Workers. Now everyone wants to do away with unions. Some of them , yes but not all. Anyway sorry about this rant. Thank you and have a good day. Boot.