I know this has nothing to do as such with diesels but since i use only diesels i might start hear .
I am experimentig with a paw 19 ds3 and it is turming a 11x3 at 9600 and giveing me 2.3 lbs of thrust

when i check on the thrust hp software it says i should get 4lbs of thrust

any body knows why?

laurence

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The chart is wrong. The tach is wrong? The scale is wrong? Anyway, it is a good question.

Where do you buy an 11x3 prop? Never heard of one with so little pitch. I guess I learned something new today.


Ed Cregger

it is an apc prop uesd for 3d flying on 36 glow but 9600 is good realistic figure for a paw 19 plain baring

There are a lot of reasons.

A. Are you at sea level? If you above sea level thrust will be lower at any RPM.
B. Most of those thrust HP softwares for models are far too simple to give a good answer. The calculations are not based on real life test of the props.
C. The method you are using might not work well.
D. All of the reasons Ed gave.

Low pitch props are also used for free flight models.

George

i prefer low pitch props for my modles cos i like slow flyers

dose any one has a leed to good software to make calculations?

Actually, a fist full of different size props and some air time will provide much more reliable conclusions as to which size is best.

George