Mark@ny

I need some help selecting a brushless motor ,esc, prop and lipos for a wattage ultimate bipe. Looking for some low budget options. Looks like a nice little plane that's built up covered and not made out foam. I have a hackerA20-20L and himaxx 2815-4000 available.I am not opposed to using a gearbox with the himaxx.

Dr Kiwi

The plane is around 32oz so the Himaxx is well suited for good aerobatic performance at close to 150W/lb...., since it is rated for 275W (86g @ 3W/g is close enough) .......(the 57g Hacker can't manage that). Determine the correct prop size then gear accordingly... at around 4:1 gearing you'd have a Kv of ~1000Kv which should allow 10"-12" props, while keeping the amp draw at ~ 25A.

Mark@ny

Thanks for the info, I could use a little more info. What company gearbox? What amp ESC ? The plane was originally designed for a 7x4 prop. 10" I think is the max that could fit. I have a 25 amp brushless speed controller to use if possible. I am not looking for 3-D performance just good spirited flight.

Dr Kiwi

Why don't we go with your 25A ESC and an 8x4 APC E: I'm guessing your motor would fit a GWS 400-style gearbox. One can get several different ratios. http://www.allerc.com/hyperion-alumi...v2-p-1579.html

~260W is still ~130W/lb.. should be plenty.

Motor: HiMaxx HA2815-4000; 4317rpm/V; 4.2A no-load; 0.016 Ohms.
Battery: Thunder Power TP4400 (G4 ProPower 45C) (45C); 3 cells; 4400mAh @ 3.7V; 0.002 Ohms/cell.
Speed Control: Castle Creations Phoenix 25; 0.0065 Ohms; High rate.
Drive System: Geared; 8x4 (Pconst=1.47; Tconst=1) geared 3.6:1 (Eff=80%).
Airframe: Anything you want.
Motor Amps = 24.7
Motor Volts = 10.8
Input (W) = 266.4
Motor RPM = 44502
Prop RPM = 12362
Thrust (oz) = 31.5
PSpd (mph) = 46.8

Mark@ny

Is a 4400 mah pack necessary ? I have a 2100 mah pack from another plane don't remember the C rating. I would like to know a possible outrunner recommendation as well. Thanks for the help.

Dr Kiwi

Oh heck... sorry... that battery was just in MotoCalc and I didn't correct for what you actually need! ANY battery which can deliver ~25A will do (1000mAh/30C... 2000mAh/15C... etc... would do)....... mAh capacity will simply determine flight time.

Mark@ny

I think a outrunner might be an easier choice since I can't locate a gear box that will fit a 2815-4000 due to its 28mm outside diameter.

Dr Kiwi

This should work for a 28mm OD motor. http://www.allerc.com/hyperion-alumi...v2-p-1579.html

Mark@ny

The gearbox from allerc.com I don't think will work. Besides the o.d. of the can being 28mm not 20mm,the shaft size is much larger than the pinion available I am willing to save the himax for something else. But I would like a recommendation for an outrunner but possibly still using the 25amp speed controller I currently have. Maybe something from hobbyking or BPhobbies.
I tried to contact himax since they offer the 2815-4000 witha gearbox to see if it was available separately but they did not respond.

Dr Kiwi

I think that a 28mm OD motor would fit, but, yes, you'd need 3.2mm pinions.

Here is an Exceed 2220 motor (28mm OD) in a similar gearbox.

Mark@ny

The pinion shaft is 4mm. Do I still use a 3.2mm pinion and press it on or is there other mods to be made. Thanks for the help.

Dr Kiwi

My mistake.. I looked up Himaxx 2815 and their chart said 3.2mm for the three lower Kv versions... but I missed the fact that the -4000 is 4mm!! http://www.rcdude.com/servlet/the-49...nrunner/Detail


I don't even know whether 4mm pinions are available.

aeajr

My Feedback: (2)

I find the electrifly calculators work well to help define a motor or specs to use to go shopping
http://www.electrifly.com/powersyste...tem-index.html

I have had very good experience with Rimfire motors.

Mark@ny

Thanks for the response. Since writing last I was given a HK 2040 4800kv inrunner I have an e flight 6.6 to 1 gearbox . Is this a usable combo with a 25amp speed controller ? What prop?

Dr Kiwi

At a guess I'd say about 12x6 on 3s would draw ~20A.

I'd certainly start with no more than 10" with my Wattmeter in hand!