Radio Ruminations

Currently there are three 'price points' in the heli radio market. In the $200-$250 range, you have the six-channel Futaba 6X, JR 622 (or is it the 642?), and Airtronics RD6000. In the $400-$600 range, you have the eight-channel Futaba "Super Eight" and the JR 8103. In the just-over-$1000 range, you have the nine- and ten-channel Futaba 9Z and JR 10X, respectively.

I can't say much about the 6-channel radios as I have little experience with them. Suffice to say that they will do all you need for hovering, forward flight, and basic (airplane-style) aerobatics. The JR is somewhatever preferable to the Futaba in my humble opinion. The Airtronics appears superior to both in most ways, but I haven't seen one yet so I can't say for sure.

The 8-channel radios will do everything you need, ever. When I got into this, I assumed that if I stuck with it for a while and "got serious," I would upgrade to one of the $1000+ systems, but here I am four years later with three helicopters and nine plaques from various contests, and I have yet to feel limited by my radio. I might get a 9Z if I find a great deal on one, but I'm in no hurry.

The 'flagship' 9Z and 10X will do everything you need, and then some. If you really want one, go for it. If you're wondering if you need one, you probably don't. Most folks I know who use these radios have most of the advanced features disabled, making me wonder why they didn't stick with an 8-channel system and pocket the extra $500-$600 they spent on unused p-mixes and disabled flight modes.

RCD/Hitec makes radios that cost significantly less; I want to believe that they are indeed a better deal, but I've been burned in the past when buying less expensive equipment (car stereo quipment, for example). Sad, but true. Maybe if I knew some folks with RCD gear I wouldn't be so cynical?

See this page for a quick overview of the PCM vs PPM (aka FM) tradeoffs.

Flight Packs

For my first heli - Kyosho Concept SRX - the standard S3001 servos included with the Futaba 8UHF system were sufficient. With one ball bearing, a speed of .22 seconds and 37 oz/in torque, they are run-of-the-mill servos. For a beginner-s 30-size helicopter, they're adequate. The tail rotor servo was the first to be upgraded, as a JR 2700G took its place. This set of servos performed well, even in an Expert fun-fly contest in which I took 3rd place and in freestyle contest in which I took 3rd and 2nd places.

After 3 years of continued (ab)use, one of the S3001s failed in flight, so I retired the whole set. So, if you're learning with S3001s or servos of that caliber, don't feel like you have to upgrade them to get good performance. They work. But relegate them to an RC car or something less dangerous after three years or so, OK?

When I bought my Futura SE, I put in what I thought would the 'best of breed' for each servo. If you don't see your current favorite servo listed here, that's because this was in 1996...

Collective: JR 4000
Cyclics: Futaba 9202
Rudder: Futaba 9203
Throttle: Futaba 9403

In retrospect... I have a JR 2700G rudder servo in my Concept, I think it might be a little faster than the 9203. Not by much though - some experiementation is in order here. I doubt the difference is all that great. 2700 and 9203 are both great rudder servos. Airtronics has one of the same caliber, but I haven't tried it. It's part number 987654321 or something like that.

Where do these people come up with their servo part numbers? Airtronics especially. What is it, the telephone number (or extension) of the engineer who developed the servo?

Anyhow, I figured the 9403 would make a great throttle servo since it's pretty fast (.16 or .17 if I recall correctly) with medium torque (just under 40 oz/in). The throttle requires the least work (or torque) of any of the servos, so 40 oz/in is plenty. The high speed should make it a good match for the GV-1 governor. Seems to work quite well!

The JR 4000 is a remarkable servo. Fast and strong. I can't imagine a better servo for collective. You may have read the ads where they talk about trying to twist a servo arm while the radio system is turned on - they claim that regular servos feel kinda squishy but the JR 4000 feels like the gears are locked... It sounded bogus to me, but they're right. If money's no object, they probably would make for great cyclic servos as well. I might even try one on the throttle with the GV-1, I don't know.

So far I have no complaints about the performance of any of the servos. The Futura flies wonderfully, so I'm not really in a hurry to change anything.