motor size question

[rcflier1]

ok, 1st scale build. phoenixtech mechanics in a airwolf fuse. i,m only used to 3d set ups. something tells me the xnova 4025/1120 i have for it is way overkill. what motor/ pinion do i really need

[rcflier1]

guess i should have also said 600 size, using a 6cell 5000 pack

[Trooper7]

1. What head speed are you shooting for? (usually 600 size 2 blade scale 1350-1400)

2. How many teeth on the main gear?
3. What battery power, 6S, 8s, 10s, 12s....?


Then we can help sort you out.


Cheers.

[Andy01]

Originally Posted by rcflier1

ok, 1st scale build. phoenixtech mechanics in a airwolf fuse. i,m only used to 3d set ups. something tells me the xnova 4025/1120 i have for it is way overkill. what motor/ pinion do i really need

Try this formula-


RPM = kV x (# of cells x 3.7V) x 0.9 (efficiency) x pinion teeth / main gear teeth = headspeed at 100% throttle towards the end of the flight.


Then, depending on what ESC you have you can work out a governing factor - eg. most CC ESCs like to run between 90-95%, so you can use the formula to play around with motor kV and pinion teeth to get it where you want it.


For the record, I run a Xera 4030-470kV (XNova predecessor) in my 4x 600mm 12s Seahawk at 1350rpm headspeed, so I doubt a 4025 is overkill if it gives you the speed you are looking for.


Colin

[rcflier1]

ok, thanks. i have no idea what headspeed i,m looking for. 1st scale build. i,m used to headspeeds over 2k. with that being said,, motor is 1120kv, 6 cell 5000 pack. 120 esc and the main gear is 170 teeth. airwolf fuse, and i want it as lively as can be. slow straight and level is not my cup of tea. even my 1/3 scale super cub gets banged around once in a while.

[Andy01]

I would suggest that a typical headspeed for a 2 blade scale 600 might be around 1500-1600rpm (I fly a 2 blade 500 at 1700rpm), but this might not be lively enough for you, so you might want to aim for around 1700rpm at 90% governor - that way you can increase governor to 95% (another 100rpm roughly) without changing pinions.


Colin

[rcflier1]

doing some research, i,m thinking a 14 or 15 tooth pinion. and than using the governor.

[Andy01]

Something to bear in mind is that the 170T main gear (assuming it is the old Trex 600 "standard" gear) may take some strain in a scale fuselage if flown aggressively.


There is a big difference in forces between throwing around a pod and boom and a fuselage that weighs a few pounds.



My 600 Seahawk has never given me any issues but I fly gently and upgraded it to a 164T Trex 700 gear which has about 50% wider tooth face.


Colin

[Trooper7]

I fly a 700 size B222 which weighs 14lbs so very similar to your Airwolf.

Head speed is 1350 IDLE UP1, 1400 IDLE UP2 Using Spinblade Asymmetrical 600mm 69mm chord blades. I find this gives me pretty spritely flying ability.

5000mAh gets me about 7 minutes of flying using 10s.

I would replace the Main Gear with the Black 13mm thick option if you plan on anything more than moderate sport flying.

Use a lower head speed gain setting to help reduce the chances of a pinion stripping the main gear.

I'm unsure if they are a direct fit for the Phoenixtech but, if able, I'd replace the tail drive gears with the Align 'Red' gears which are quite a bit more robust.

I fly what I call mild/moderate sport with it. Here's a video:
In this clip I had a peak amp of 42 and average of 21amps aka 1700W and 760W respectivley.


Trooper7's Bell 222 (6 min 11 sec)




With your 1120kva motor, 6s power, 170T main and 12T pinion you could run a headspeed range of 1350 - 1450 giving an ESC output of approx 86-92% respectively - which is well in the ball park for efficiency.

Because your using 6s you will see higher amp draw than my 10s. ie. for my flight above those numbers for you would be 77amp peak and 34amps. As long as you have an ESC capable to handle these numbers your good.


Your motor has 3000watt (continuous) limit which is more than enough.


Also note that the higher amps will shorten your flight time for the same 5000mAh supply.


Last thing, be careful doing tail slides against the anti torque. I avoid them in this direction as the loads on the tail rotors put huge strain on the 'Umbrella' gear set between the AR gear and tail transmission/drive.



Cheers.