Brushless question

I just received a micro brushless Hacker motor. It has 3 black wires - does it matter which one is negative/positive? Is there any polarity? I assume it must not matter if they didn't bother marking the wires, but this motor is too expensive to risk it...

TIA,

Loren

Hi General,

I'm a german pic-flyer and will try to answer your question:

You can connect the (3) wires of the "HACKER" to each port of the controller. If the direction of rotation is not o.k. you can either change (2) of the wires or re-program the controller.

By the way I tend also going "brushless" and followed intensively your BB. Is there anybody out who has technical information about the ASTRO 010 concerning efficiency vs. torque or current, rpm/Voltage etc. As I am looking for a german brushless motor (LEHNER 1010 with 34 turns in star-circuit)...hope this is the correct translation ;-)) this motor will provide then 2040 rpm/Voltage. I also will keep the piccoboard because of the HL. The contoller will be connected to battery and motor. The gas/pitch signal will go to the piccoboard for tail motor mixing and to the controller (w/o connecting the +-wire, cause BEC is used from the piccoboard).

I hope my postage will be understood (regarding translation....)

REGARDS TO ALL PIC-FLYERS within THIS BB...

MARTIN

[pgoelz]

Hi Martin,

Sorry, I do not have the exact RPM vs. voltage figures but I think the Astro 010 is higher than that.

With the ten tooth ECO8 pinion, the 010 is about right on 8 NiMh cells. Since your motor will be slower, the larger pinions available for the ECO8 should work well.



------------------
Paul Goelz
pgoelz (at) eaglequest (dot) com
Piccolo web page: http://www.eaglequest.com/~pgoelz/piccolo1.html

Hi Paul,

thank you for the answer.......... ;-)
Here is a assumption concerning your PIC-LAYOUT especially with the ASTRO 010:

- hover-rpm because of cut blades 1200 rpm
- gear ratio 96/10 = 9.6
- motor speed for hover = 11,520 rpm
- 8 cells deliver approx. 8 V (not best case)
- Conclusion ASTRO 010 part load = 1440 rpm/V
--------------------------------------------------
- Assumption for fast take off (full load): rotor speed = 1600 rpm
- motor speed 1600 x 9.6 = 15,360 rpm
- 8 cells deliver 8 V for full load
- Conclusion ASTRO 010 full load = 1920 rpm

Therefore I assume the LEHNER with 2040 rpm/V is not too bad.............

OR am I wrong ...................

Many thanks for the answer and

REGARDS

MARTIN .... sitting in the office and thinking about brushless layouts ... hm, hm hm

[pgoelz]

I hover at about 1350 RPM. Your assumption about 1600 RPM for full power is probably pretty close, since I have a lot of available power. I hover at about 60% on the throttle stick with the Sanyo 720 mAH NiMh.

It also flies with 7 cells, but all I tried was the 10 tooth pinion and it didn't have the blazing power I was used to!



------------------
Paul Goelz
pgoelz (at) eaglequest (dot) com
Piccolo web page: http://www.eaglequest.com/~pgoelz/piccolo1.html

Hi Paul again,

I am a bit unsure to buy the LEHNER brushless motor, because you can choose out of so many turns. I learned from this BB that the ASTRO 010 is suitable for the PIC.

So my question:
Where can I order this little motor ? I have gone thru the web sites of TODD's and found that he delivers that piece w/o controller for $75. Do have experience how long it lasts to ship it overseas and what's about the additional shipping costs ?

Is there any other way to get this POWERFUL ENGINE?

REGARDS


M A R T I N

[pitts_s1a]

Martin,

Just to add to the confusion , the Astro's KV is closer to 2200 RPM/V, and this is, I believe, measured with no load. The actual KV under load should be different.

The Lehner at about 2000 RPM/V would need a change in gearing, but should be suitable, since the typical S280 has a fairly low KV itself, probably around 2000 RPM/V, possibly slightly lower.

The motor isn't really the limiting factor, the gearing will be. The Lehner motor should have enough torque to overcome any gearing limitations, but this is at the cost of efficiency. If you could get a larger pinion, like the ECO pinions as Paul has suggested, you should be fine. But since it is so close to the Astro's KV, you might not even have a problem with gearing.

You're talking about a difference of maybe 1500 RPM at the shaft, maximum, which when translated through the gearing to the head, with a 10:1 reduction, you are talking about a 150 RPM slower head speed. The actual difference under load may be even less. Something like that can easily be compensated for with a pinion change, or cut blades. You're going to have to cut the blades anyway, so you should be able to make it work by adjusting your cuts.

Phil.