I set up a cool field box out of a standard Hobbico kit. It contains a small 12-volt battery inside it that powers two chargers - a standard hobbico field charger, and a Great Planes PolyCharge 4.

My Field Box

This charging setup is great, but I have found out that the PolyCharge draws way too much current for the little battery I have in the box. The Hobbico charger works with it, and I can charge about 4-5 batteries before killing the 12v, but it takes forever with it as I can only do 2 at a time, and it only charges at 1C, where the polycharge goes up to 3C. So I need a car battery for the polycharge it would appear.

I didn't have a reliable 12v power supply on hand, so this charger was useless to me unless I had one, or wanted to use my car every time. So I took an old PC power supply and hacked it up!

Check it out - I used some radio-shack bits in it, and it can charge 4 batteries in around an hour! It doesn't balance, but that's just fine. My existing (slow) balance charger can top them off and balance them well. I just short-charge them in the polycharge, and then throw them on the balancer to top off and balance them out. I can get all the batts charge in about 1-1/2 hours. Perfect!

Closeup of 2 1-ohm 10 Watt resistors - why? PC power supplies are switching PS's - which means they automatically shut off if they don't sense a constant load. Since battery charging does not "draw" a load, this application will never work unless we simulate one. So we attach two of these resistors in series across the 5v supply in this PS (the RED leads are 5V, yellow are 12v and orange are 3.3v, and it provides enough constant draw to keep the PS on! I used thermal grease to contact the case as these will get very warm.

PC PS voltage reference - the following graphic helps you understand the voltage supplied to the corresponding wire colors. They are fairly standard, and I doubt you'll find many PS's that deviate from this standard color scheme. Handy little thingies, these.

Bourry pic of all the leads - clipped off and terminated

It works! - that's the idea... two simple terminals providing 12v, and one simple on/off switch. Beautific. I could have also added terminals providing 5v and 3.3v respectively, but who needs 'em? This works fine.

No more worrying about dirty brushes, and motors fading... I remember back in my RC car days, my motors wouldn't last that long because the brushes were constantly getting funked up with dirt and grease.

Check out E-Flite's lineup of brushless "outrunner" motors:


I happen to have a few E-Flite Park 480's. They have lots of power, and can propel my airplanes vertically with unlimited rollout power. Really beefy motors, and great for these park flyers I'm learning on. I actually have two of them that I got in a cool bundle with my RcBrio10 models... buy the motor, and get a plane kit thrown in for an extra 20 bucks.

Wicked little beasties, these puppies are volatile!. [old man]: "Kill ya soon as look at ya..." *spitooooon* Truly they are well known for catching fire at the drop of a hat. And we're talking flashpowder-like incineration:

But these puppies produce some serious juice for their weight, so they are extremely popular. People have taken to building "Battery Bunkers" to house these in. I am seriously considering getting a fireproof safe to keep mine in.

These puppies are not cheap either. A 3-cell LiPo pack will cost you about $65-75 bucks, and they are fragile enough that in all 5 of my electric plane crashes, I have only had one survive. One dent in the cell and you better discharge and throw away else you risk turning something it's near into charcoal.

I am going to post info about my attempt to build an airplane motor out of a CD-Rom. I found a cool page that shows you how to reuse a CDRom motor and turn it into an ultralight R/C Airplane motor! Now that's resourceful!

http://homepages.enterprise.net/jayjay/cdrom_motors.htm∞

This trick is probably old hat to anyone who is deep into this hobby, but it's new to me! If you want to give it a go, our man here does a great job of walking you through how to go about it. And it figures he's from the UK... the brits always did make better engines than we did... :) But I'm gonna try it out and we'll see how it goes! Look for a project page link from here...