I like it, this is a real world test.
Just a question though, shouldn't you deduct the jig drag first before makeing assumptions?
25-12=13 and 50-12=38
So either 13/38 almost 1/3 less drag from fixed to free wheeling.
or
38/13 almost 300% increase in drag by not allowing the prop to free wheel.
Thanks for the insight.
Since you are kinna have the jig and all maybe you might try to a torque number with a stalled prop?
Maybe a one foot bar attached to the end of the shaft to your scale and the hinge locked.
Quote:
Originally Posted by Maine Sail
No not necessarily. On this jig it related to 25 pounds and this jig showed roughly a 50% difference. Due to the angle of the rope and some other factors it is tough to calculate an accurate drag number.
I also load tested the jig alone, without a prop, at WOT and it had about 12+/- pounds of drag so you would need to subtract the 12 pounds from the 25 or 50 pound numbers to even get close. I think it is safer to say something like "nearly double" the drag difference rather than apply a number in pounds. I leave the .001's up to MIT...
Pretty close an not bad for a back yard hack who did not go to MIT... |