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Old 02-20-2008, 04:47 PM
  #65  
z06kal
 
Join Date: Jun 2004
Location: Woodland Hills, CA
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Default RE: sick of jetts

Last I checked this was the high performance "extreme speed prop planes" section not the "old timers having sentimental feelings about out dated technology" section.

You always have this type of silly human sentimentality and resistance whenever anything new comes out. You can look at litteraly anything and find the same resistance to change attitude. Just a fact that humans don't like change.

I flew glow for 10 years however I'm always up for whatever offers the greatest cost/benefit relationship.

All I hear is a bunch of whining about the sound. I thought this was the extreme speed prop planes section? As any of the fast electric guys will tell you if you are spinning a 7x7 or bigger prop at supersonic speeds the crack of mini sound barriers is so much louder than anything coming out of that tiny hole in your muffler. Most people can't even tell much difference in sound in the air between a 2000-2500 watt electric motor spinning 28,000rpm or a Nelson/Jett spinning the same prop at similar rpm as the sound of the prop is far louder than anything else.

When I was flying this plane:

http://www.youtube.com/watch?v=3b32TrOxF6Q

compare the sound to this plane (exclude sputtering of poorly tuned motor)

http://www.youtube.com/watch?v=ZVs4NEtYnM4

Everyone thought it was powered by a Nelson or Jett .40 until they saw me taxing it back and realized it was electric.

So the sound argument in an extreme speed prop plane section is pretty lame IMHO as if you are turning the prop fast enough you shouldn't even be hearing much of the engine noise. Also it's not like these tiny displacement single cylinder 2 strokes have this amazingly beautiful perfectly harmoneous balanced sound coming out of them. Clearly an electric car will never sound as good as a Lamborghini or Ferrari V12 but give me a break you are talking about an engine that sounds identical to my gardeners leaf blower when he is pushing leaves around in the front yard. Not exactly special sounding. Which would you rather have an engine that sounds like a kitchen appliance or a gardening tool? Not exactly a winner here.

Also the price/cost relationship is starting to really really fall into comparables. For example for $100 motor/esc combo from united hobbies you have a power system better than your average .91 2 stroke. You can also get a decent lipo battery to power it for about $150. Thats the same price as your average .91 2 stroke with a gallon of glow fuel except with some care that battery will last at least 150-200 cycles even with just 6 minute flights thats equivalent to at least 9 ounces of fuel (realistically more with fuel wasted in start up, run up, tunning, filling etc). Thats 14 gallons of glow fuel and even the low nitro stuff is at least $10 per gallon. And this is not even taking into account the cost of a wrecked plane that is the result of a dead stick. When you go into smaller scale the performance/price/cost of operation/ease of operation swings even more highly in favor of electric.

Right now you still end up with a very heavy plane if you want to fly something like a Patriot 60 on a Jett Fire .90 with equivalent power and speed for a full on 12 minute flight. Methonal has something like 100 times the power density of lithium and for this reason glow clearly takes the nod. In RC applications however the IC engines are highly highly ineffecient and so electrics can compete better. Many people are more than willing to take the full power run time disadvantage of electric to the ease and reliability of operation.

Most of the other arguments are really bogus however. IF you have multiple packs you can basically fly as much as you want without waiting for charging just plug in the pack and go while the other packs are charging. Even refueling and starting dialing in takes time.