fizzwater2

My Feedback: (61)

It's been many many years since I flew a 1/2A RC plane. Back when I did, it was bantam midget servos from Ace, and a 500 MAH battery pack 'cause that's all I had!

I'm building an Ace Upstart II (picked up the kit from a local flea market!) and have been giving some thought to more modern, lighter radio gear. I've got Futaba S3017 servos, JRSport SM15's, and perhaps even a couple Hitec HS85's. I'd like to use the JR servos, but if the HS85's would be a better choice for aileron / elevator I'll use them. For RX, I've got JR R700's or Hitec Electron 6 - or should I get one of those little HFS04 or HFS05 receivers from Hitec?

What batteries are you guys using in your 1/2A planes? When I pylon raced a while back, I was using 270 MAH nicd's. What do you think of some of the smaller NIMH cells available these days?

Like I said, it's been a while..

Thanks!

Andrew

FIZZ -

The Upstart is about 200 sqs. IIRC, so weight is a real consideration. I think the HS-85 is overkill. The JR SM15 is a little light on torque -- expecially if you have any binding. The HS-81's are heavier than the JR, but have twice the torque. I've used a bunch of these with good results. A servo that I think has some real promise is the Futaba S3110, wt. .27 oz and torque of 22 in-oz. I have not used the 3110, but a couple of the guys on the forum have without problems. Tower has them on special 3/$42.47

The Electron 6 is a good choice.

I've been using 350 and 370 mAH NiMH packs -- they weigh a tad over an ounce. A 350 NiCad weighs over 2 and a 250/270 NiCad is about 1.6 oz. The only drawback to the smaller NiMH packs is that they need to be form charged at C/10 -- many of the smart chargers won't time charge at that low rate so I ended up having to build a simple constant current charger.

That's ma story and ahm stickin' to it.

ptulmer

My Feedback: (5)

300mah Nimh batteries weigh just slightly over an ounce and give a lot of flight time. You can pick up cells on ebay, or buy 8 cell flight packs and split them up.

MJD

My Feedback: (1)

I posted this a while ago in another thread:

"Just passing along a data point for those obsessed with lightness.

I bought some 220 and 300mAH NiMH packs from Tower to convert into 1/2A Rx packs. I weighed a 4 cell pack of each type:

220mAh, less connector: 22.4g 0.79 oz
330mAh, less connector: 31.7g 1.12 oz

A connector will add 1 - 1.5 g (0.04 - 0.05 oz) to that."

These packs were made from Tower Hobby 7 and/or 8 cell power packs for park fliers. It was PTUlmer that turned me on to that idea, as these packs are very economin, econin, oops.. they are very cheap.

But they do, as mentioned, require form charging.

These or other smaller packs will be a vast improvement over a 500 or 600 mAH NiCad pack, which is more likely about what, 75+ grams?

With small servos and battery, you can often afford a regular reciever's weight depending on the model of course.

MJD

BuzzBomber

My Feedback: (4)

Inasmuch as you're discussing battery capacity and current delivery, resistance etc., didn't you actually mean "that's maH story and ohm stickin' to it"?

BTW, I agree about the use of those 350/370mah nimh packs--they have replaced the old 270mah nicads in all my small stuff these days. More capacity at less weight is always a good thing in my book.

Andrew

LOL

DICKEYBIRD

Pffft....why drag around so much battery for our short flights? I routinely use 80 mah NiMH for 2 channels and 180 to 230 mah for 4 & 5 channels. Just check the voltage after every 2nd flight and top off with a cheap field peak charger.

Here's a steal. Buy the 8 cell and split it up. 2 x 180 mah flight packs for $8.00.
http://www.bphobbies.com/view.asp?id...04&pid=U167031

Sneasle

looks good.

I still say that all of ya'll bateery experts here need to get together and write an all powerfull sticky thread specifically on receiver batteries and radio equip for 1/2a stuff.

MJD

My Feedback: (1)

I agree, though I usually find myself willing to sacrifice a little bit of battery weight for less field maintenance, and try to make it up elsewhere. Plus with the 1 hour charge rate of NiMH my patience might not hold out..

One generic sholder-wing 2-channel 1/2A sport ship I have spans 32" and weighs 11.5 oz ready to go with standard Rx, 225 mAh NiCad, and old Futaba mini servos, what are those, S133's? (It's been around a while) It is waiting for a flight pack upgrade which should dump a lot of weight. Point being though, one charge would safely give me enough battery for several flights, meaning enough flights to sate my appetite in one trip to the field. And the weight was low enough that it flies like stink on a Black Widow, 5-3 MAS, and 25% fuel.

I got a new Tower catalog last night but left it at home; the 220 8 cell packs are ridiculously cheap, what, $6.99 or something? 220 mAh is likely as small as I would ever go even with 2 channel 1/2A. But that's just me.

MJD

MJD

My Feedback: (1)

My current favorite 1/2A flight pack setup [based on what I own several of at the moment of course, upgrades possible, just add money] is:

FMA M-5 receiver (dual conversion 5 channel)
Hitec HS-55's
220 mAH or 350 mAh NiMH depending on aircraft and number of channels.

And no $#@$ switch harness, I use shorting plugs in female connectors, or plug in directly if access is simple.

MJD