Anybody knows if 22x8 props will save battery? I am willing to trade less thrust if this saves some battery.
Thanks
a smaller pitch means less air to move thus less resistance, that results in less current draw and you would therefore save energy. however you may want to not sacrifice on thrust. it may be needed to safely takeoff and gain altitude quicker, if needed.
Lower pitch requires more RPM for level flight to achieve the same watts of power. Amps and volts remain the same but the Increased RPM will make more noise.
At full throttle the RPMs will be higher too because there is less air resistance but full throttle power should be less and draw less amps.
Low pitch is like low gear on a bike. It’s easier to go up hill in low gear. High pitch is like high gear and gives you higher speed but less power. The question is: what is the optimal pitch for the speed that we fly and what is the optimal motor KV to turn it?
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Is this not the reason variable pitch props were created – a different aircraft uses different pitch - we will have a multitude of different variations of wings, pilots weights, which pitch is right!!
Cheers
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There is no perfect pitch which is why most modern aircraft have constant speed props. I have a Pipistrel with hydraulic constant speed prop, during take off the pitch is course for maximum power/thrust. During cruise the prop pitch is reduced for faster speeds, better efficiency/less drag which reduces fuel burn. If I had a fixed pitch prop I’d burn 18ltrs/hr and not fly as fast as when you have a constant speed prop that adjust the pitch for best efficiency. 15ltrs/hr. But there’s also engine rpm, you set the constant speed prop to hit a certain engine rpm and the prop adjusts pitch to maintain that rpm.
Best would be to just try the 22x8 props and see if you have enough thrust for take off safely to clear obsticals. If so then you should get longer flight time with this prop as it’s more efficient in cruise
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Thanks, I am going to try these for $75 (4 props)
Looking forward to hearing your analysis on these. This topic has come up a few times but nobody has reported on actually trying something different. In a previous thread the comment was made that if the pitch is too high while flying slow that the blade will actually stall. I don’t think this is happening but your test will be interesting to many of us.
It looks like the props you found only have an 8mm hole and I believe we use a 10mm shaft.
These ones say they have 10mm holes. If you ordered other ones it’s easy enough to drill the holes larger.
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I noticed your white props in another thread… are those the 8 inch pitch? It would be nice if you would test them with 4 batteries as a comparison before you convert to 6 batteries. I would love to hear a true side by side comparison.
Those white ones are the same as the other post. They are 22x10, I am still waiting for 22x8 to come from china to compare flight times. As soon as I get them I will test and post the results.
Are they the ones that came with the kit? Did you paint them white?
GOOD NEWS: I got my 22x8 props from china
BAD NEWS: I sold my openppg, so I did not have a chance to test them. I need > 1hour flight times, so I bought a Nitro 200.
Hey Dario, Is that set of props different from the ones you gave me?