If I go from BH 2507 avenger V2's to the BH 2806.5 motors on a 7 inch long range cruiser, would I see an increase in cruising speed? I want to go faster and also, I just want a reason to buy bigger motors ?

Could the increased torque of the wider motor also possibly help with efficiency as the quad is quite heavy at 1130g? Or does weight factor in at all on what kind of loads propellers experience during flight?

ecalc.ch can simulate some combinations for you, give it a try

for higher cruising speed you should aim longer blades befor bigger motors. if you like to go fast crousing, 9inch or bigger would match that

(28-Dec-2022, 08:41 PM)hugnosed_bat Wrote: ecalc.ch can simulate some combinations for you, give it a try

for higher cruising speed you should aim longer blades befor bigger motors. if you like to go fast crousing, 9inch or bigger would match that

Ok, will give ecalc another try, thanks! It was a bit confusing when I last tried it.

A bigger second quad or putting the parts in a bigger frame is not possible at the moment. Quad is currently cruising at 65-70km/h at 30% throttle, so looking to increase that with a motor change if it's possible. On youtube people say they cruise at 80-90km/h with these bigger motors and 7in props but no idea if that's actully an efficient cruising speed for long range flights.

it all depends on the combination, bigger motors does in creas trust, increase weight. to gain benefits out of it, higher prop pitch and fewer blades could compensate weight.

there is just a lot of hype and unusfull information around in my eyes, they actualy hype bigger and bigger motors... alot strange combinations outthere.
2306/2207 on 7inch is still an efficiency motor, it can be lightweight and have high cruise speed on a high pitched rotor. maybe you could compare the old lr 7inch settup in ecalc to get an impression of the importance about combination.

i guess your focus for high cruise speed on low throttle level doesnt match increased weight and thrust by bigger motor

Tried ecalc and if I did it right then it looks like I'm already close/at the limit of my 40amp 4in1 esc with the 2507's so I guess no big motors for me. Sad.

Aha! It would work with lower kv (obviously).

2507 1200kv Vs. 2806.5 1250kv:
Hover flight time increased from 22.3 to 22.4, so wayyy more efficient...and thrust goes from 3.7 to 4.2, so maybe faster cruising speed?

Anyways, they are worth it now, yay!

Edit:
Uuuh, Emax eco II 2807/1500kv would work too and thrust would increase to 5.1 and hover flight still at 21.9. hmmm...I hope these are comparable to the BH 2806.5 motors.

did you simulate different rotor combinations? bigger motor might like fewer blades and higher pitch

(29-Dec-2022, 03:27 PM)hugnosed_bat Wrote: did you simulate different rotor combinations? bigger motor might like fewer blades and higher pitch

I've tried several different bi-blades on the 2507's but the quad shakes and bobbles much more than with tri-blades and haven't been able to tune that out, so pretty much given up on bi-blades.

Ecalc proved to be so much fun in itself that got the full version.

Could it really be that 2806.5/1300kv with high pitch 7x5.6x3 is about as efficient as anything but they also come with highest cruise speed and top speed? I thought efficiency would suffer a lot going from 3.5 to 5.6 pitch but hover flight time reduced only from 22.6 to 22.5.

Yeah it's all give and take with cruise speed and efficiency. Only way to go faster is to use more power unfortunately or get an FPV wing lol.

My best setup was BH 2812 900kv motors with 9x5 props. About 80km/h cruise speed and about 12-15 min flights running a 5200mah 6s lipo.