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Old 02-08-2007 | 12:21 AM
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RVM
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From: Sacramento, CA
Default RE: Saito 82 RPM and Thrust Measurement

How on earth did you get 10300 RPM from an APC 14x6 with your Saito .82? With 25% Omega I peak my .82 at 9600 (with spinner, but I don't think it makes that much difference) on that prop. I'm at sea-level too.

Also, I get 8800 RPM from a Pro Zinger 15x4, which seems to put more load on the engine than the APC 15x4w. I once got the APC 15x4 to peak at 9660, but the best peak I've gotten since is about 9450, and that was on a bench. On the plane it's never been higher than 9200 RPM.

Either I've got a really crummy engine or you've got a really good one.

ORIGINAL: seanychen

Here it is:

Fuel, 30% heli, Wildcat Youngblood Mix
Temp: around 80ºF

APC 14x6 @ 10300 rpm = 9.5 lb
MA K-series 14x6 2nd gen. @ 10600 rpm = 9.25 lb
APC 15x4W @ 9700 rpm = 9 lb
Pro Zinger 15x4 @ 10300 rpm = 8.75 lb


Tachometer: Royal Tachometer
Thrust measurement is done by attaching a digital force gauge with an extension bar, hooking to the Sullivan tail gear brass collar on a Funtana 40.

All measurements are sustained reading, not the initial peak reading.

This confirmed what I found in the air, that APC 15x4W does not pull as well as APC 14x6.

If anybody has different thrust finding, please post. Thanks[8D]