method_a

I'm generally a fairly smart guy, but...

I just picked up a Mini Piper kit from Hobby Lobby, with their recommended accessories. I did upgrade to the 5ch Hitec reciever, for room to grow.

This is my first RC plane in a long time (built a 2m, 2ch glider 15 years ago, flown twice, crashed once) I'm stuck on step 0 of the instructions of the Mini Piper.

I went to lay out the electronics, servos, reciever etc to charge and test them before I started the assembly. I cannot for the life of me figure out how the wiring is supposed to look. The diagram in the Hitec manual seems to be for a non-BEC setup. How does the wiring setup change for a BEC type installation? And does the mini piper use a switch and charging pigtail in the wiring setup? It seems a switch would improve safety, but I can't figure out how it gets integrated into the tangle of red and black wires on my desk and I can't see any mention of a switch in the plane's instructions (other than the safety instructions which mention turning off the plane before the transmitter)

The battery obviously connects to the motor, and the motor to the reciever. Does it matter which channel this goes to? The instructions show channel 3 for the throttle, but theyhave the battery marked on channel 5.

Any help would be appreciated! I feel like an idiot, but I'd rather lose my electronics in a tree rather than burn them up on a bench.

BykrDan

I had precisely this same trouble when I was faced with putting the Piper together. Here's how it works:

Rudder and elevator servos plug into socket 1 and 2 on the receiver (I can't remember which is which, but that's easy enough to figure out).

The motor (throttle ESC) goes into socket 3.

The fifth socket, marked B/S, is empty - power is provided from the motor through the third socket.

There's no switch or charging socket in my setup, as I think most people just unplug the battery to charge it between flights. And I think your better off without the extra weight anyway.

If you have the three-channel Hitec FM SS radio, the throttle is off when it's all the way toward your left hand (that is, toward the edge of the radio case). The throttle must be off when you connect the battery to the plane, or the ESC won't arm and the plane won't take off (that's the safety feature in place of the switch, I suppose).

Now, here's what confused me greatly the first time I tried this: The plane will work with the motor connected to the battery socket (number five), but in that case, throttle is reversed, and both rudder and elevator are mixed on that socket - that is to say, the first time I went flying, left rudder kicked the motor on - hard - and right rudder stopped it. Likewise, down elevator would throw the motor on full power, and up elevator would stop it! Ideal conditions for learning to fly! Not to mention, I had to re-learn how to use the throttle when I got that mess straightened out.

Nonetheless, my Piper held up through many crashes and other dangers, and has recently been fitted with a parachute drop. Still oodles of fun...

Hope this was helpful,
Dan.

Matt Kirsch

My Feedback: (21)

Yep, the Hitec manual describes a typical glow setup with a receiver battery. The switch and charge pigtail connect to the receiver battery. Of course, with a BEC, none of that is necessary.

Any switches you see in electric planes only control power to the BEC, and thus to the receiver. The power from the main battery is still connected to the motor, and the speed-controller part of the ESC is still powered up. Normally it won't operate without a radio signal, but there is always the chance of a freak component burnout and the motor suddenly going to full throttle with no warning. It is always safest to completely disconnect the battery from the ESC when you are not flying.

If you have a three channel transmitter, only channels 1, 2, and 3 on the receiver should be used. As Dan pointed out, you will get erratic results if you try to use any of the additional channels. Some radios completely ignore those extra channels, some do weird stuff, and some actually "multiplex" the signal from another channel to the higher ones. That is, for some transmitters, channels 1 and 5 do the same thing, 2 and 6 do the same thing, etc..

method_a

Thanks all for the help. I do have a 5ch radio, so I'll save the extra slots for later. I'm glad I wasn't the only one confused by the setup.

method_a

Now that I've unpacked the electronics again I remember the second half to my question:

The hitec AC charger has a flat, black 3 prong plug, and the battery has a squarish red plug. I had assumed that to charge the battery I'd just go from battery to charger... Do I have to cut that plug off and solder in a battery connection on the hitec charger? The kit I got does come with a battery plug lead, but I assumed that was to connect to the terminals on the 12V charger I got.

This is why I was under the assumption that I should have the switch/charging pigtail in the system somewhere...

Thanks!

Matt Kirsch

My Feedback: (21)

Most chargers don't include charge leads, because they don't know what you'll need/want. There are many different types of plugs. You need to buy or make up your own leads. It's an annoyance, but also a tradeoff. Do you want an affordable charger, or an overpriced charger and a pile of leads you'll never use?

The red plug on the battery is called a "male JST." You need a female JST, and a set of banana plugs.

Another option is to pull the outer sleeve off the 3-prong connector, it just pops off with some careful pulling, and carefully plug it into the battery, making sure to match red-to-red, black-to-black.