rscamp Veteran Location: Ontario, Canada
| Pipeous
You have been doing your homework!
A few comments for what they are worth.
The speed constant of the motor isn't the only thing to worry about. Efficiency at operating current and power dissipation should also be considered. This informaton isn't easy to come by, but qualitatively the Kontronik Tango is a proven heli motor and I think it is the best choice for this size of heli if you want to use Kontronik stuff. It runs quite cool. I would see if this motor will fit in the mount.
I have a Tango 45-06 in the Shuttle and a 45-08 in the Logo. The 45-06 is a bit slow, so the Shuttle is quite tame on 20 cells. If you had perhaps 24-28 volts at your disposal from LiPos, the 45-06 should work very well in the Shuttle. With LiPos, it makes sense to get more power from the available voltage (i.e. more power from the "V" in P=IV).
I'm really struggling to picture how a 10-12 NiCd/NiMH cell approach would provide good performance in such a large and heavy helicopter. I know of many who have converted this size of helicopter successfuly using 18-22 cells, but I know of no one who has used so few cells. Yes, it is lighter, but the airframe is heavy and the power system will require high currents (i.e. the motor will get very hot!) to provide reasonable performance. With electrics, the batteries are part of the motor (they determine available power through voltage), and only 10-12 cells makes the motor too small.
As for gearing in the Shuttle, if you use the stock pinion with the motor, controller and battery count suggested herein, it will work just fine.
The Beat 50-8-30 is a good choice. I have two of these - one in the Shuttle and one in a Logo 20. Very smooth starting and good current headroom. Governor mode makes set up a snap - no throttle curves.
I wouldn't worry about the CPS computer programming feature. I've tried it and found it is not really necessary. Sure you can vary just about anything you want, but I found I just didn't need to. The standard helicopter mode in the controllers works just fine.
Rob |