When making the shift from 2" to 2.5" props on KT_Bug, I chose a brand I really like...HQProp.  They make the "HQProp DP 2.5x3.5x3" and having used their DP line before, I figured it would be a good choice.  They are very tough and have held up to some heavy abuse without a single broken or bent blade.  I did manage to chew the end off though, but any prop would have done it for how it happened.



These props are "locked in" and the craft responds instantly to throttle and attitude inputs.  They provide some very nice lift and the power is perfect!  Under no powered flight have I detected vibration that could not be explained by some other effect on the craft.  I feel these are some of the smoothest props I have flown KT-Bug with.

This performance does seem to come at a cost in amp draw.  I am finding that under hard flying, 2.5 minutes of flight on my Tattu 3S 650mah 75C packs and I start to get LV warnings.  Dropping back little, there is usually another minute of mellow "cool-down" flying before landing.  This is about 1 minute less than I was able to achieve using the same packs using even the worst 2" propellers.

I decided to try another offering, the GemFan "Flash", 2540-3 prop set.  These come in a bag of 8, so there are two complete quad sets for the price.  These feel very similar to the 2" Hulky's that I flew for a few sets in testing.  They are likely about the same strength, so will be able to stand up to being scraped and and scratched well enough.



These also did not appear to cause any vibration under the different loads they were placed under during test flights.  One difference I observed was that the GemFan's are quieter than the HQ's.

Flight testing, interesting result!  They are very smooth and quick to react to attitude changes.  For that, they apply their power with less aggression and it takes a little more throttle and I found myself having to be a little more cautious about diving the yard.  They are certainly fine for most flight, but I may actually like the high AOA of the 1/3.5 a little better.

Even requiring more throttle, these GemFans definitely are less power hungry.  Same approximate flight at the same velocities, I was able to get over 3.25 minutes before the first LV alarms.  Landing at 4 minutes found the Tattu's holding enough charge for a little more flight.  They are definitely efficient and would be a great choice for "endurance" flights.



I would recommend each of these propellers without reservation, but would note that each really fills a different requirement.  The HPProp for racing and agressive flying and the GemFan props for mellow longer flights.

Hope everyone is having the best evening and hope I maybe provided some info that will be useful