Any thoughts regarding a flight pack for a Monarch D? What would be the best battery, receiver and servo combination?

From : Don Stackhouse

Joe Hahn has been experimenting with 3-cell packs lately, with outstanding results. Using a 3-cell 50 mah nicad pack, a Hitec 555 Rx and 2 HS-50 servos, we've seen usable battery life exceeding 40 minutes per charge, and no problems with servo torque.

The lower voltage results in less current draw by both the servos and the Rx, which results in greater battery life, provided that the servos can still get the job done at the lower voltage. So far the HS-50's haven't had any problems in this regard on the Monarch's ruddervators. The new Wizard 'Lite' has re-designed control linkages and hinge layups that allow the use of HS-50's on the flaperons.

Three cells doesn't seem to work nearly as well with the FMA S-80's, because their current draw seems to be much greater. I don't have any info on their new S-70's.

It's tough to get the C/G to come out right without nose ballast, but it can be done. Use one of the pushrods for the Rx antenna (there's an article in "Ask Joe and Don" on our website that discusses this), and use your very best building skills. At the nose, get everything as far forward as possible. Joe was coming close to a "no noseweight" condition, with the 2 servos stacked on top of each other, and the Rx behind them. This required a fairly large gap between the battery and the servos, to allow room to get the battery out. A possibly better arrangement, which I plan to test on my own 'D' soon, is to mount the Rx with velcro just behind the battery, then put the servos behind that. This moves both the Rx and the servos further forward, since you can peel the Rx loose from the velcro to get the battery out, which means you don't need to leave a space between them. In addition, the Rx is heavier than two HS-50's, so all of this helps the C/G. In any case, if you do a good building job, especially on the tail, and the wing dihedral joints and t.e. attachment, you should need little or no ballast.

Don Stackhouse
DJ Aerotech