Most efficient easystar motor?

Hey guys, I'm trying to decide what motor to purchase for my new easystar. At first I was thinking outrunner because they are generally cheaper and lighter weight. However, I want to have the most efficient setup possible to extend flight time as much as possible. I don't really care about having insane speed capabilities, or amazing climb rates, just efficiency. The easystar (for obvious reasons) needs a small prop, so why use an outrunner motor, when outrunners are meant to be high torque motors?

So bottom line, which do you think is more efficient for the easystar, outrunner or inrunner? What size would be best for just general, high efficiency cruising?

And in terms of a prop, I've heard that 7x5 props cut down to 6x5 are really good, has anyone tried this?

Views: 931

▶ Reply to This

Replies to This Discussion

Permalink Reply by Riccardo Kuebler on February 24, 2010 at 12:27pm
Exactly!

Thank you very much to have recovered this link.

Ric

ModeratorPermalink Reply by Krzysztof Bosak on February 24, 2010 at 10:58am
One blade also means more vibration. What is balanced statically, is not necessarily balanced dynamically under load.
Permalink Reply by Mike Bakula on February 24, 2010 at 12:56pm
That's true -- one-bladed propeller designs for rubber power often have the counterweight out a bit on a wire, and well behind the plane of rotation. The idea is to use centrifugal force (roughly speaking) to generate a torque that opposes the torque at the blade root due to thrust. I haven't run the numbers, but I'd be surprised if it worked well at other than the design RPM.
Permalink Reply by Pawlenko Michael on February 26, 2010 at 10:22am
The propeller is balanced at 8750 rpm. My motor is doing 8450 – 8500 rpm. As long I’ll not exceed 8750, I’ll stay out of trouble.
The motor is a Lener type XSP turbo 1930 44 Volt – 1900/2000 watt. The gearbox is from Hacker and has a 6,7:1 ratio. I use a YGE120 HV speedcontroller and in the battery are 12s lipo cells 5000 mAh.
@Rana: I use the motor now for 2 seasons. The gearbox and motor are still clean, no grease is leaking from the ball bearings, no strange noises. In total, I charged for 89 times my 2 lipo packs. According to weather conditions, it takes 2 minutes to fly to an altitude of 500 – 600 meters. A charged lipo pack gives me the possibility to take of 3 times. After 3 times, the lipo pack isn’t flat, but have less power. A 4th take of is possible, but I reach only 300 – 400 meters.
For maintenance I use a 10 cell nicad pac of 3 cell lip pack. This gives less rpm but also no vibrations.

If you take a close watch to Rana’s first photo, you can see on the spinner (bottem of prop) that it can balance to the front and back (vertical). This means, when the prop turns, it takes the best possible position, thanks to the centrifugal force . Pitch remains the same.


Motor: http://www.lehner-motoren.com
Controller: http://www.yge.de/artikel.php?search=yge120hv

Hope you can read my bad english….

Michael
Permalink Reply by Mike Bakula on February 27, 2010 at 10:23am
I see what you're saying - very nice!

RSS

Contests

Season Two of the Trust Time Trial (T3) Contest has now begun. The third round was a reliablilty/aerial photography round for both planes and copters, which is now closed. Stay tuned for the next round, beginning soon.

A list of all T3 contests is here. 

 

Top Content 

1 What do you think the APM should do on fail safe

What do you think the APM should do on fail safe
2 ArduCopter 2.5 released!

ArduCopter 2.5 released!
3 Brainstorming Specifications.

Brainstorming Specifications.
4 Housekeeping note: Kevin Finisterre

Housekeeping note: Kevin Finisterre
5 Hexa-copter found after failed attempt of delivering cell phones to inmates of a Brazilian penitentiary

Hexa-copter found after failed attempt of delivering cell phones to inmates of a Brazilian penitentiary

Groups

© 2012   Created by Chris Anderson.

Badges  |  Report an Issue  |  Terms of Service