I recently purchased and constructed a Slow Stick. But now I am having a problem in the final stages. I need some assistance with the installation of the power pack / battery as it connects to the receiver and motor.

Here it is:

I've got a Hitec Tx/Rx. The plane came with the 300 motor. I purchased a battery pack (9.6v 750mAh 7 cell AAA NiMh pack), and a 5amp ESC.

I am having trouble seeing how to connect the ESC and the receiver / servos both to the battery at the same time. Is there a splitter or something required?

In the meantime, to make sure things work, what I have done is take a 4 cell AA NiCad 500mAh pack from an older Futaba of mine and connected it for the receiver and servos, and connected the ESC / motor to the 7 cell pack.

I realize that this might be some extra weight, but from what I've read, this plane can take some extra without much problem. And this setup also might be a little more advantageous due to the fact that one battery pack isn't controlling the ESC, motor and servos.

Does this setup make sense, or am I doing something wrong or need an extra set of wires / splitter.

And secondly, determining the center of gravity. I don't grasp the whole concept. I know that the plane needs to be balanced so that it is not to nose or tail heavy. I've got the leading edge bracket 5" from the front of the fuse, as the directions dictate. What is used to balance it? Do you slide the servos back and forth? Or the battery pack?

Other than the above, the plane went together fairly easy, although I didn't care much for the half-assed directions supplied. It seems as though it could have used a few extra illustrations, and directional steps for beginners like myself. It really seems as though it is missing a lot. I constructed a glow trainer about ten years ago, and the directions with that were much more detailed and easier to follow.

Any help you can provide is appreciated. Thanks for your time.

Sincerely,

Robert (beginning flyer)

Robert,
One plug on your esc goes into the receiver. The other plug goes to the battery. You cannot mix them up as the connectors are different. Make sure the the wire alignment to the receiver matches the wire alignment of the servos (i.e. black wires on one side, red on the other as they are plugged into the receiver). The ESC will only fit the battery one way. It won't plug in any way but the correct way. The third lead from the ESC is to the motor Again, align the wires red to red and black to black. Measure back from the leading edge of the wing... I think it is 45/8" for your balance point (check the instruction) Make a mark at that point under the wing next to the fuse. By moving the wing and battery back and forth, you will eventually find the balance point (cg) by placing a finger tips next to the mark you made on each side on the underside of the wing.. The balance point can be elusive due to the different sizes and weights of the batteries. You may end up with the leading edge of the wing as far as 61/2" back from the tail end of the motor. If you err, do it in favor of a little nose heavy rather than tail heavy. Any more question, refer to this forum. Someone will help you.
Ken

Wouldn't a 9.6 volt be a 8 cell? I'm new to the electrics also. I think the 7 cell would be 8.4 volts. Is this right?
rcflier47

That's correct.
NI Cads are 1.2 volts per cell.

That's correct.
NiMh's are 1.2 volts per cell.

Robert,

The only real problem I see is the ESC rating. My Slow Stick came with the EPS-300C "D" motor gear-box, with an 1180 prop. I run it with a 7-cell NiMh 1300mAh AA sized pack, and it draws 8.3 amps at full throttle. Start-up current is a bit higher, but the ESC should be able to handle short duration spikes. If you are in fact running an 8.4V pack, you might be OK, but definitely not 9.6V. The fact that current rating is a function of thermal dissipation, and the ESC on the Slow Stick is out in the open and convectively cooled by constant cool moving air, the ESC may handle more than rated, but why push it? Even though you may typically run the SS at 2/3 throttle or less, you will in time diminish the life of your ESC. When it goes, you may lose 100% control of the plane. Again, it might be fine for a lifetime, but when starting out, it a good idea to aim for a reduction in variables.

Almost all ESC's have battery eliminating circuitry (BEC), which means that it actually provides power to your receiver and servos by regulating down and siphoning off your flight battery pack. It only connects to one point on the RX, namely the throttle servo connection (Ch-3 for Hitec). This is generally prefferred to using a separate battery pack as you mentioned, although you're right, the Slow Stick could handle the extra weight. I've seen set-ups where a "Y" connector is used to specifically power one servo from a separate pack on larger planes, but if you plan to use a separate pack, I would plug it into the battery port on the Rx, and probably disable the BEC connection on the ESC connector to the RX. I think cutting the middle wire would do it, but take a look at the ESC and Rx documentation to make sure. Disabling the BEC may not even be neccessary here, but with 2 DC sources, the ESC may do something screwy with the auto cut-off. Again, not sure, but I would fly without the separate pack anyway. There's no reason to add the extra weight, even if tolerable.

I think Ken answered the CG question. I've only had my SS for about a week, and I made the sucker really tail heavy doing tail-feather mods, epoxy embedded carbon fiber, etc... as well as the other "standards," balsa in fuse, epoxy and fiber-tape everywhere. The finished weight, with battery and very heavy Hitec 7-Ch PCM Rx is ~20.5 ounces. I balanced it as the instructions said, and the battery is right up against the back of the motor. I had to change the order of the mounting pieces. Anyway, I've only flown it once. It took off from loose dirt in exactly 9 ft, in light wind, probably too much wind for a pilot of my ability. The plane flew a bit loopy and tried to go vertical whenever it got the chance. I think Ken (And many others) are right that the CG needs to be a bit forward of where the instructions say. I'm not sure how much, as after about 5 mins, I crashed it directly into the ground. I have to say, this thing took a header like a champ. I literally stuck it head first into the grass on a soccer field, and the only thing that broke was the prop. Of course everything slid down the stick, as I didn't fix them in place in order to tune the CG, but that's it. A crash that only cost me $1.75.

I have a prob with my slow stick, could anyone help me? Ive been a flyer for about two years now and a builder for about 4 and I recently got a 1200mAh li-poly for my slow stick. I set it up without thinking of the CG and went to fly and struggled. I went home to adjust the CG but I couldnt seem to get it in the right area. Ive tried moving the wing, the battery, the electronics but I cant get it. heres a pic, can you tell me what I should do?

Bigjake,

Checkout my post and Look how I mounted the battery forward of the wing. was the only way i could get the CG right.


http://www.rcuniverse.com/forum/Slow...1646193/tm.htm

Dont be afraid to add some nose weight if needed.

If you have a red 2-pin connector like those on GWS ESC's, then connect the battery to the 2-pin red connector, the motor to the 2-pin black connector, and the other end goes into the speed control plug on the reciver.
With the EPS-100 (which is a better motor, from what I have heard, for the slowstick) you need a 5 amp ESC. The EPS-100 should have at least a 7 amp ESC. The Pixie-7 is the best for the the EPS-100, and the EPS-300 works great with the Pixie-10 or higher. The E-tec 1200's might have some trouble with the EPS-300, so try some High Discharge Kokam 1500's (35.00 a pack). They are only a few grams more, and can take up to speed 400's. The AAA's you are using should be fine for both motors, although you may as well go LiPoly, as the flight times are well worth the extra cost.
A word of advice:
NEVER, EVER, EVER use Li-Pos with a GWS ESC. They will wreck the batteries if you are not constantly checking the voltage. You will save money in the long run by getting a Castle Creations ESC, partially because they are lighter, have nmore features, and are more durable than the GWS crap. 2 GWS ICS-100's are more expensive than one Pixie 7, and the Pixie can take 50% more amperage.

Thanks, my plane balances perfectly... man I love this plane. thanks for the tips.