Glow Engine Vs. Electric Engine for 2 m' pattern plane

[Richard Strickland]

The street price for my FMA/Kokam packs will be in the $400.00 range/set(I think), but they need a little more capacity.  Give it a little more time--there are becoming some alternatives that will help pricing and reliability.  Put these critters in a light, clean airplane like an OMS with retracts and I'd bet you'd have plenty. Icepoint?!

Richard
  ----- Original Message ----- 
  From: Jeff Hughes 
  To: discussion at nsrca.org 
  Sent: Wednesday, June 01, 2005 5:10 PM
  Subject: Re: Glow Engine Vs. Electric Engine for 2 m' pattern plane


  I also got the electric bug, but the battery cost always seems to overcome my excitement. I used 8 gallons last year and havent' got through my first gallon yet this year. Though I typically end up using 10-12 gallons of 15% on my OS1.40's. Which means buying a couple of $700 battery packs totally out of the question. Hopefully this emerging technology won't drive away even more of the guys like me  who are lucky to get out once a week during the summer. 
    ----- Original Message ----- 
    From: Richard Strickland 
    To: NSRCA 
    Sent: Wednesday, June 01, 2005 11:25 AM
    Subject: Fw: Glow Engine Vs. Electric Engine for 2 m' pattern plane



    ----- Original Message ----- 
    From: Richard Strickland 
    To: discussion at nsrca.org 
    Sent: Wednesday, June 01, 2005 11:22 AM
    Subject: Re: Glow Engine Vs. Electric Engine for 2 m' pattern plane


    Guys,

    I'll jump back in here; Jim, your perceptions are correct.  My decision to go to Electric was based on some fairly bad luck with engines last year--It was time to up-date power-plants as I was driving my old stuff to pieces trying to get all the power I could out of them.  I purchased what I thought was going to be the hot ticket engine and had a series of unfortunate events with it.  By the end of the season, I hadn't done a lot of flying--but had had a load of problems.  It was time to re-evaluate what I was doing.  My business doesn't allow for scads of practice time, so when I get the chance--I like for it to count. Since I try to do things as right as I can, I generally end up with three sets of everything eventually--you know; the Primary, the Back-up, and the One you're building--never seems  to quite work out that way--but at least it's the plan.  I was flying Temptations, but had crashed one and hurried to get the second done and while pretty good airplanes, I was beginning to think there might be a change to a wider body style in my future. 

    So basically I was looking at a clean slate.  AND I had 15 years of accumulated stuff to sell since the last time I sold off my stuff to start over.  I heard and read about some of the guys having success with electric and was intrigued, fooled around with the smaller park and indoor stuff and got to know a little about it--decided with proper care, all parts of the systems are pretty reliable and reasonably safe.  I talked to a couple of the old hands and a couple of fairly young guys and they were all enthusiastic about the larger stuff and so I thought--"Hey, I've got to get to know some new power-plants anyway--why not get up to speed with electric?! "  I got hooked-up with FMA through the small stuff because they treated me fairly on some of the issues I was having and were designing some battery protection features, cell balancing chargers and some new batteries for the larger stuff.

    Initially, I thought about--actually, I had made up my mind--to do a Plettenberg outrunner so I wouldn't be dealing with gear-sets.  Eventually, It became clear that between what was available a few months ago and the Hacker--that the Hacker set-up was going to give better performance.  One person likened the Plettenberg to a good 110 system and the Hacker to a good 160 system.  That may have changed by now--but you still have to look at weight vs. performance.  I ordered an Impact--but had the brand new IC powered, reasonably light Temptation that wasn't selling and decided to convert it.  That turned out to be fairly easy.  First I started with a conversion mm kit from Esprit out of Florida--but we saved 5 oz. by going to a solid CF nose plate and end grain reinforced balsa in the rear opened up and then the whole front of the airplane is open for cooling.  The batteries mounted exactly where the tank was--I beefed the mounting up a bit.  I put on a set of Matt's gear.   I'm making weight by all of .5 oz.  I may be a smidge tail heavy and may run the rec. batt to the front.

    Flying.  I'm fooling with the throttle curve a little--experimenting with the feel.  I'm guilty of probably not experimenting enough sometimes when something already works pretty well.  It's probably not a whole lot different than the difference between two and four cycle--but my experience is limited there also.
    There may be some interaction between what the FMA discharge protection modules(DPMs) and the controller is doing in regard to throttle response and how the motor surges to signal you're running low on electrons--but so far, everything is working reliably.  We also know we're driving the hell out of the 3200s--but I can't stand any more weight--so I'm sorta stuck for now.  They've got some experimental 4000 10s2ps that Orland is going to try--but they weigh a few oz. more--but he's got lighter airplanes and can stand it.

    I mentioned time--45 CONSECUTIVE flights with a complete pattern in each.  12 or so trips to the field and power-plant related problems have not ruined a flight.  I haven't had to 'tune' for the first couple in a session--first is identical to the last.  I'm working on throttle management--it's different.  I'm looking at this as a transitional year--to learn, to see what works best for me, to figure out the logistics of charging at home and the field--or on the way, to make it safe--all that good stuff.  So far I'm satisfied with the results.

    Got windy again, I see..........

    Richard
      ----- Original  

      Having flown Tony's Partner only once (but watched it fly quite a bit), and having seen just a few other electric pattern planes (Jason's, and Billy Meadows'), the flying advantage of the electric was enough to make me want to get one going, regardless of the learning curve.  From my perception, the pilot does feel the difference between the glow and electric setups regarding less vibration.  The plane is going to be easier to setup for a constant speed envelope, where there is less of a "gap" between slow and full-throttle horizontal velocity.  With the narrowed speed envelope, it MUST be a tad easier to setup the plane as the "one" setup has a smaller velocity range to work and be consistent in. 

      I'm just trying to stir up another side of the discussion.  I hope that some of the folks who have more of the "flying" experience with the electric 2M setup will relay their experience, and describe to us the piloting differences, trim differences, etc. 

      Thanks All, 
      Jim W. 






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