The ORCA requires a three or four channel radio in order to operate the rudder, elevator, wingerons, and speed control, however, if desired, the rudder can be “fixed” and the ORCA may be operated using a three channel radio.
We recommend using a micro receiver and low-profile servos. Prototypes have been flown to depths of 8 feet in chlorinated pools using both the Hitec Electron 6 and JR micro receivers without the need for an external antenna.
The Novak Rooster reversible speed control (#1850) was used in our first prototype, and worked well, however the Novak XRS reversible sport model is less bulky and easier to fit within the WTC.
Motor and Drive unit:
Prototypes were flown using the Graupner direct drive Multispeed 601. It comes with a speed 600 motor, shaft and stern tube which has a lubrication fitting. It also includes a prop.
The largest prop that we’ve used is the two-blade Graupner 50 mm GR231450, but we think that this setup will still handle a larger prop. Hobby-Lobby now carries an adapter which will allow a 3/16” shaft U.S. prop requiring a drive dog to be installed on a Graupner 4 mm threaded shaft. This makes propellor options unlimited. We’re eager to test some Octura props on this setup.
Onboard battery pack:
The ORCA has been powered using 6 or 7 cell NiCd packs in the capacity range of 1800 mah with very good performance. In an effort to keep the cost under control, and because of the potential unfriendly environment (i.e. water), we have not tested any of the more exotic battery packs yet. :