1/4 scale super cub power system
I'm going to start building a Hanger 9 1/4 scale super cub shortly ( soon as I get all the parts) but my question is about the eflight power 160 motor that I have purchased for it. I went with the 160 because everyone said that you have to add 16oz of lead to the nose if you used the recommended 110 motor so I went with the heaver motor to make up part of the difference in weight. The specs on the 160 says to run the 160 on either 9 or 10 cells , what happens if I want to run the 160 on 8 cells ? Would it be too inefficient? I allready have a one large 4 cell lipo so I was thinking I could just buy another one and run it on 8 cells.
Also can I run an old lipo with a new lipo in a series or should they be both new ? What about if I bought a 5 cell and run it with my old 4 cell in series ? Thanks for any HELP you can give .....
It will run fine on 8 cells. You just have to be careful not to overprop for the voltage because current is not longer the limiting factor, heat is. The motor will overheat before current will tell you you have too much prop.
You won't need anywhere near the power it can produce on 8 cells so this won't be a big issue if flying in a reasonably scale manner.
When doing series packs you must have the same C rating and the same capacity. Its better to have packs that are the same age and have essentially the same usage history.
I avoid using more than a 4S pack because all of my higher cell count packs have had the middle cells fail early. The middle cells have a harder time getting rid of heat. If the packs have to be stuffed in with no airspace between its important to get them out and separated so they can cool after a flight.
fhhuber thanks for the reply,,,
Do I understand you right the motor will over heat easier because running on 8 cells instead of say 10 ? I was going to start out with the 19 / 10 prop.
Thanks for the tips on the 4 & 5 cell packs .. sounds like good advise !! Makes sense ..
If there will be plenty of power with 8 cells // say 2 - 4 cell 5000 mill amps packs then that would probably be the way to go then ,, I would think .
Thanks for any info you can pass on ,, I do appreciate it !
If you don't have one, be first in line at the local hobby shop to pick up one of those wattmeters. Doing without one while juggling prop sizes on your motor/battery pack is like driving your car without a speedometer. With the police radar guns checking every 1/4 mile down the road. Push your motor/ESC/battery just a little bit, and it might cost you.
I had a giant scale Piper Cub back in 2000. That model didn't need much power to fly, about 1200 watts was plenty for a 15 pound model. Back then this model required 38 Sub C nicad cells to power a geared Astroflight 90 motor, turning a 20X10 wood prop.
This type of model would do well running at around 100 Watts per pound of airplane weight. Little more would not hurt.
The issue with under-voltage is inadequate rpm to develop cooling airflow in the motor, so you have to keep the load down a bit to reduce the heat produced.
Not a big issue with excessively abundant power available. Just watch the motor temp in addition to current.
You can also add baffles and ensure good cooling air flow path (4X as much exit area as inlet) and avoid the issue.
|All times are GMT +1. The time now is 10:29 AM.|
Powered by: vBulletin
Copyright ©2000 - 2013, Jelsoft Enterprises Ltd.
Copyright 2005 WattfFlyer.com
RCU Eflight HQ