HELPFULL TIPS - HOW TO DO IT'S - IDEAS PAGE
BUILDING ELECTRIC pg 2
steeper pitch. An example would be changing a 20 X 10 to a 18 X 12, or if the next flight I decide I want to do 3D and hover, a 22 X 8 might be the call. More volts and fewer amps are slightly more efficient than the other way around, what that really means is at some point you may need to add more cells to get the desired effect if you can’t keep everything running cool with your propeller choice. Think of volts as the potency of the fuel you’re using while amps would be the volume of fuel you’re flowing at that time, when you put your foot to the floor to go faster the fuel doesn’t become more potent you just use more of it, or flow it faster. So how do we measure volts and amps, keep reading.
Myth #1- It sounds too complicated and it’s too hard to figure out what to use. With a simple amp-volt meter, tach, and digital fish scale (used to measure thrust and the weight of the plane) you can quickly see if it will fly and maybe how well. The Internet is full of helpful sites as well. A simple clamp on amp and combination voltmeter is very helpful, I got mine from Sears on sale for 29.95. I love the clamp-on’s as you just clamp them around the positive lead of the motor battery while under load, if you’re going to do this “E” thing it will be the best thirty bucks you’ll ever spend. If you get a clamp on amp meter make sure it measures DC current and not just AC. In the end you don’t really need any equipment, just copy what others have done.
Myth #2- Lithium Polymer batteries cost too much - yes they do you’re right, but at over two bucks a gallon so does gas. Li-po’s purchased within the last 18 months or so usually cost less than NIMH or NI-CAD’S if you measure them by the energy stored. Newer batteries are also commonly going way beyond 400 cycles and Lithium-ions are close to 1000 cycles. Remember no one chose this hobby because it’s cheap, and like any other hobby or sport, you can do it at any level that suits you. Folding and flying paper airplanes is cheap, flying turbines is not, electric falls in between, just like gas or glow. I have friends who dropped 40K on a fishing boat and then tried to convince me how cheap it is to go fishing every weekend. Electric is probably a bigger layout up front, but within a few flights I’m convinced it’s cheaper, and I do find that I fly more. If you really enjoy the flying part of the hobby and your time is limited I don’t think you can beat it, remember it’s just my opinion mixed with some loose science and this information is free.
Myth #3- I’ll start with NIMH or NI-CAD batteries and brushed motors and work my way up to save money. Don’t do it, newer brushless motors are almost bomb proof, last forever, and are up to 50% more efficient than brushed, they truly can make the difference between success and failure and today the good stuff isn’t always more costly.
Myth #4- This is just a fad, it won’t last much longer. Yeah, and cell phones are trendy and will never catch on. I remember when the first four stokes showed up and everybody said, no way they cost way too much! It’s just a fad, they could never replace the good old two stroke, some people even wanted to ban them from their fields. Electric plane sales now out number glow, not in the big ones but that may be coming.
paulb@jeld-wen.com
801-209-0293