Folks,

Some quick background. I have been flying real sailplanes for three years, and I had to quit because I moved. That was five years ago. Fairbanks is not quite the right area to get back into real sailplanes, so I figured to try myself at R/C. I realize that the real thing and R/C are quite different, but at least I have some background on the theory of flying etc.

Anyway, I am starting out and could really use some advice. I ordered a Java 150 powered sailplane (http://www.hobby-lobby.com/java150.htm) which should arrive in the next few days.

I don't have anything else, but a few of the tools needed to put it together. I was looking at a radio and got an offer to buy a used JR XF622 for $60 shipped. I have no idea if that is a good deal, there is nothing with it but a charger and the manual. Unit is in good condition, about 5 years old, battery holds charge. Should I go ahead and get it? I am a bit on a budget, but from what I have read the overall tone seems to be to buy a good radio early on, even if it pushes the start-up costs up a bit.

What about servos? Do I really need to worry about weight a lot? Hobby Lobby (HL) recommends HS300's. Depending on voltage applied they deliver 42oz or 49oz of torque at 1.75oz of weight. Is it ok to run servos at 6V to get higher torque? Should I be looking for lighter weight servos?

Batteries. HL lists 8 cells 600AE for this model. I am thinking to get 7 cells RRC-1000AE NiMH instead (radicalrc.com) pretty much same price but lighter and better performance. Figuring 100W per lb, 2 lb flying weight, at 30 Amps, thus 200 W / 30 Amps = 6.67V, at 1 V per cell I should be fine with 7 cells. Which brings me to another question, what runs off of which battery. It seems like the RX runs off of its own battery and the servos and the motor have a seperate one. Wouldn't it make more sense to have the motor have its own battery and run the RX and the servos of off the same one?

I know I know, I should look for a local club and find someone to teach me how to fly. Read that over and over, I get the message. I did contact the local club, posted to their mailing list, got one response in the two weeks since I posted. Not sure what the problem is, but seems like there may not be much help available. Plus they also don't seem to fly much in the winter (looks like 99% of them are glow users). I do plan to get everything completed in a couple three months and have my maiden flight in late January, early February. No matter what the weather is like, and you better believe that I will be out there at -40F giving it a shot.

Anyway, I figure that I start with hand launches, not using the motor and just letting the glider fly straight to get a feel for the controls. The snow cover will prevent hard landings, and I will practice with a simulator before, perhaps I will have made some contacts with local R/Cers by then. For now I just need to get the gear to build the plane and set up the radio and such. Any advice will be much appreciated, and thanks for reading through all of this.

Edit: Did I post this to the wrong forum? Should it have been in the Electrics forum instead?

Servos - I would use lighter servos than the 300's. They are cheap ($10 per) and strong but big and heavy. I would use 81's or 85's. They are more expensive $20-30 apiece.

Battery - Most speed controllers plug into the main (and usually only) battery pack. The output plugs into the motor and also has a line that plugs into the rcvr. If you get NiMH batteries make sure your charger can accomodate them. I would get the NiCad pack for your first setup. They have a reputation for reliabilty and ruggedness.

There are a lot of electric sailplane fliers on the forum. Maybe we will raise one for some expert help.

I think you may want to give more thought to battery efficiency vs. temperature. Battery performance is directly proportional to temperature. At -40F I suspect your batteries will be basket cases. Maybe better to wait for the spring thaw!
Puff

battery efficiency at low temperatures

I had been looking into that a bit already, -40F is most likely out of question, even if keeping the batteries warm until launch. Though I won't have to worry about this if the waether stays as it is, it is in the upper 30's F. That is the warmest winter since I have been here.

Anyway, flying at low temperatures is something I will worry about once I have actually build the plane and hooked everything up. Not sure how long that will take.

I made a decision about the radio already, I will just get a 3 channel Hitec that comes with servos and RX. Not the best setup out there I am sure, but for someone who still needs to figure out if RC is the hobby to spend time and money on, it seems like a good choice.

If you have to test and learn on your own then do all the test gliding with the prop off and a small direct connect battery for the radio. This will ensure the model doesn't have a sledge hammer inside waiting to bust things up......

For your first trim tests you can learn a lot about the elevator trim by holding the model overhead with your hand at the balance point and just run with it into the wind. If the model is close to being in trim you'll feel it get light in your hand without trying to pull away. If it feels heavy or pitches down add up trim. If it tries to pitch nose up or pulls hard on your hand then add some down. At a good trot it should feel light but stable. When it feels right you can try just letting go but keep your arm bent so you can reach up and grab it if it tries to nose up. When it's just right you'll be able to let go and have it settle back into your hand after a 6 inch glide. At that point only can you go for a full test glide. Do the same run and just pull your hand away and this time stop running and get your hand back on the stick to be ready to add some control. Testing over tall grass can be helpfull too...... Try to learn that a little elevator goes a LONG way. Unless it tries to nose into the ground just let it land. If you see the nose coming up then blip in a quick stab of down elevator just for a split second or it can turn into a nose dive very quick. Once it comes up to the stall it's all over at that height. And you already know that no airspeed means no control so you gotta get it flattened out before it gets too slow.

Once it's test gliding well then you can move to a long shallow hill and test glide it off the top and extend your glides to learn how to control the model. With models perspective and model attitude awareness is everything. If you can project yourself into the cockpit you won't have any trouble with your background. But that projecting thing is HARD. Full size pilots are often the hardest cases at accepting this last point. Be humble.....

And finally a little hint about that coming at you control reversal confusion. It helps to just turn so you're pointing the antenna (cockpit) the same way the model is flying and then look over your shoulder. After a while you'll only have to turn the transmitter slightly to orient your brain and shortly after that it'll be automatic.

Good luck and welcome to modelling.

I am just upgrading from a xf 622 to an x-347. The 622 is good to start with but will not support a 4 servo wing. Also if you want spoilerons or flaperons the 622 has only one setting for them. In other words the brakes are fully on or off. I fart in it's general direction. I paid more for my 622 than my 347 darn it. If you plan to stick with r/c sailplanes you will most likely end up with a 4 servo wing. I picked my 347 up used for 140 shipped. Well worth it cause now I can camber change to my hearts content.

Thanks BMatthews, your suggestions will help a lot. Did you ever consider writing FAQs on the subject?

Thanks to everyone else as well, I will bug you with more specific questions once the kit arrives.

Only if someone will ask me.......

I had a brand new model do a face plant and destroy itself thanks to not knowing what I wrote in the above. That was almost 25 years ago but I've tested every glider and a few powered old timers as I described and had 0 problems since.

It was worth the worn fingers if it saves the nose of at least one model.

I am amazed at how much you know just getting started!
When I started my first plane was a sportavia (COX)
A ready to fly motor glider.(cheap). Im sure they make
something like this now. All foam- All Controls included, etc.
The point is your gonna stack it anyway(if your like me)
so why worry about what weight your servos are!!!
I do not fly with motors anymore, but I do not agree with the
advise someone gave you not to use motor on the first run.
It was great for me to get as much distance from the ground as possible, to have time to get used to the controls.

Dude- GOOD LUCK
Harvey

where can ya get one today?
[email protected]