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AeroJim
05-18-2008, 08:01 AM
Hi Guys,
I need to build a test stand for testing/rating props. It needs to run them at up to 7500 RPM and I will be measuring static thrust vs. power input. The current requirement is for testing 16x14 props, but I may need to do other sizes eventually. I'm thinking a large brushless airplane motor (2HP or so) might work. The stand will be stationary, so there will be only propwash for cooling and, to make things worse, there will be a 4 inch prop spinner and motor fairing to minimise turbulance. I can add cooling fins to the fairing if needed, and some vents for the motor, but it won't see anything like the airflow you'd have in flight.
Being a lab set-up, I don't have the usual power and weight limitations as on a plane. I just need to find an efficient motor setup that can spin the prop up to that RPM more or less continuously without smoke.
Is this even realistic, or should I be looking at another type of motor? I found some long-skinny DC servomotors that would fit behind the spinner, but they're big-$$ and it's hard to find one that will do that kind of RPM without gearing. Any advice?
Thanks!
Jim

ron_van_sommeren
05-18-2008, 09:58 AM
Several test stand designs, ranging from simple&cheap to elaborate&$$$/€€€
http://www.rcgroups.com/forums/showthread.php?t=386175

Several e-flight calculators:
http://www.rcgroups.com/forums/showthread.php?t=606703

Vriendelijke groeten ;) Ron

Dr Kiwi
05-18-2008, 03:59 PM
I'd look at Neu Motors - Steve has several motors capable of 1000's of watts.

AeroJim
05-18-2008, 08:24 PM
Wow, thanks for the links. It'll take some time to digest, but looks like a lot of good info.
Jim