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Old Aug 16, 2004, 11:15 AM
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jrb
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Edina, MN, USA
Joined Oct 1999
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One thing for sure about electric flight is that there is no one way to do it! As referenced in the article I’ve flown my American Flyer with several different set-ups and others have flown theirs differently than mine.

One parameter that didn’t get listed in detail in the article that influenced the motor selection was to maintain a current in the low 30s.

If you look at the AXIs, Mega, or even the Jeti 30/3 smallish props can only be used – 10” max. The 30/3 on 12cells gets near glow rpms on roughly the same prop as a typical .40.

But that’s not the best “prop” for the mission profile of a trainer.

The 2826/12 (available after 8/20) would provide about the same performance as the 45/3; the 2820/10 is too hot like the 30/3. Outrunners aren’t as easy to mount either.

The amp draw of the configuration described is gentle on both the motor and ESC; barely warm upon landing. This provides headroom if more power is wanted; but more importantly doesn’t overload things to the point where you might have an exciting motor/ESC issue with a student at the controls (i.e. throwing a magnet).

Prices have been moving in the right direction; but its true this cost more than the glow. The ESC is a few bucks more than a .40, then add the motor and batteries – buying several years of fuel in advance. A recent article showed that a detailed analysis of a .40 conversion with LiPos has a lower per flight cost.

But here’s a real advantage; between Rick (the owner/student) and I we have four 3000+ packs and can get 4 training flights in by abusing our lunch hour by an extra 20-30 minutes! No goop to clean or cranky engine to deal with.

Peak a pack while the plane is readied, and peak the others during the other flights; the packs can be swapped faster than a glow can be re-fueled! And when we leave no one knows that we’ve been – i.e. a puddle of fuel on the ground.
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Last edited by jrb; Aug 16, 2004 at 11:18 AM.
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