Which glider is a better pick for a beginer?

[Craftydan]

Yeah, Nothing last forever.

The nickle based packs can be replaced -- in some cases with modern lithium based batteries (LiPo, LiIon, LiFe, LiFePo₄). The Lithium packs carry more capacity for the same weight and volume, but they're more sensitive to the charge cycle, so you'll have to charge those outside the radio on a specialized charger.

New TX/RX packs can get pricey, but it's usually much less than a new transmitter and matching receivers. On the positive side, you won't need an RX pack for your trainer -- you'll need a modern battery to drive the ESC and motor (NiCad/NiMH packs are heavy and lack the current depth LiPos have), but the ESC will provide regulated power back to your RX from the battery.

In your upcoming build, since you've been planning a truly silent flyer, a simple voltage regulator can suffice in the place of the ESC. If you go with one of the foamboard airframes or Full Radian (something that requires 2S or 3S packs), you can use the same battery pack your trainer plane uses.

 

[The Flying Tuba]

I might build nose for the BoT. For days when its theres no wind at all.
Edit: a powered nose.

 

[Craftydan]

Coincidentally . . . I'm in process of doing that myself:

 

[The Flying Tuba]

Was looking over my radios in detail. What does pcm/ppm mean

 

[Craftydan]

PCM and PPM refer to how the transmitter formats the data going to the receiver.

In its PCM mode (pulse compression modulation) your radio transmits over the air a serial signal (digital in time) to the receiver, which then converts it to pulses the servos can understand.

In its PPM mode (pulse-to-pulse modulation, aka cppm -- combined ppm) interleaves the analog (in time) signal the servos understand (every 8th pulse belongs to the same channel), and transmits that over the air. It has far less information, error checking , and a lower data rate, but works with more receivers.


In the end, most of this is invisible to you, other than it either "works" or it doesn't.

If your reciever can handle PCM, then use that -- you'll get better performance out of it. If it doesn't, trying to use it will end up with a confused receiver (it can't make sense of what it's hearing), so switch back to ppm and it should just work. PCM is better, but fewer RXs understand it, where PPM is more widely understood among receivers.


In a big-picture view, this is one of the big changes between 72MHz and 2.4GHz -- how the signal over the air is encoded. For most 72 radio gear, the encoding is basic FM modulation of the signals the servos understand directly. No error checking, no failsafe commands, no extra info just a constant cycle of pulsewidth for each servo that the Rx divvies out among its output channels. The radio is talking directly to the servos, with the reciever acting as a postman, dropping the pulses in the right servo "mailbox", depending only on the order they were received . . . But the postman never looks at whats in the mail.

In modern radios (futaba PCM was a precursor to this) the transmitter talks directly to the receiver, sending it data it must interprete to know what to tell each servo -- more like a nurse interpreting a doctor's orders to give specific care to each patient (servo), rather than a postman simply delivering the message without any thought to the contents. The rub comes in that the postman doesn't need to understand the message themselves to pass it along, but the doctor-nurse must speak the same language for things to work.

When you start to look at newer radios, you'll start to see more about compatibility and protocols between TX and RX, and basically that is trying to address the "do they speak the same language" question.

 

[The Flying Tuba]

Oh that makes sense. I gotta say yall have been a wonerful help to me. I really appriciate it.

 

[FAI-F1D]

I'm gonna just jump in midstream here. First, the BOT is not an easy build for someone returning to the hobby. It's a pretty complex bird, albeit easy to fly. The Oly is an absolute sweetheart of a glider, just as good as the BOT for plain old floating, and a super easy build. I'd recommend building that one first. Since you're going with a pure glider at this point, I'd recommend against fussing with a foamie. If you fly over tall grass you're not going to crash hard enough to hurt anything, and even if you do, the fact that you built it means you can repair it easily enough. I personally find foamies just don't repair as well as balsa, and they sure as heck don't glide anywhere near as well.

Anyway, just my two cents. It's more or less how I got back into RC after a long absence. All that said, don't rule out electric. At some point you need to try it. The performance available today is absolutely breathtaking. Lipos and brushless motors have brought us to the point that we can pack enough power into a model to climb vertically out of sight and still have a lower wingloading than an unpowered Sagitta from the 80s!

 

[SlingShot]

The Oly is an absolute sweetheart of a glider, just as good as the BOT for plain old floating, and a super easy build. I'd recommend building that one first.

All that said, don't rule out electric. At some point you need to try it.

What he said. Nice call on the Olympic. I was curious about it as it appears to have a flat bottom wing. I had an opportunity to fly a modified 99 with a flat bottom once upon a time and it was great. A far more superior experience in strong wind compared to the original under cambered wing.