Need help getting/keeping GWS Pico J3 in the air

I haven't flown for a few years, but I decided to get back into it by
getting an electric park flyer. When I was flying I was fairly adept
at slinging my LT-40 around the field, and could manage my mid-star 40
pretty well too. But I can't seem to keep this GWS Pico J3 (
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) in the
air. I'm a complete novice at hand launching, so any pointers there
would be great. The kit came with no guidelines for control throws, so
could anyone give me an estimate on those? Basically I'm trying a
fairly firm toss at full throttle, but it won't gain any altitude, and
within 20 feet it lands pretty hard, not nose first, but hard enough
nose down to break the motor mount.
Any tips/tricks would be greatly appreciated.
Reply to
eric_amundsen
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Some more data. I have Great Planes ElectriFly C-12 Micro Brushed ESC w/BEC with 5-Cell 6V 270mAh NiCd battery and the stock motor and prop (IPS-CB power unit with an EP1047). When assembling, I plugged the battery into the ESC with reversed polarity for about 5 seconds (duh). Could I have fried something in there enough so I'm not getting the neccessary power? I don't have a current meter handy, but I did an RPM measurement and it's putting out about 2700 RPM - is that enough?
Thanks.
Reply to
eric_amundsen
Use 7-8 cells or 2s LIPO of about 350-700mA/h. 9x7 or 10x8 prop may be better
6 cells is not enough to blow your farts away
For sterling performance use 3sLIPO and 8x6 prop....ive got this combo on a small model with B gears and it climbs like a homesick angel. 7oz AUW with 3s kokam 350.
Reply to
The Natural Philosopher
Alright, so looks like I don't have enough umph. Which is rather irratating, as I bought basically what tower recommeded. Yeah, yeah, I should have done my research and all that - but for reasons I don't want to go into here, I need a plane in the air by next Saturday and we don't have a hobby shop in town right now. So I'll probably order something a bit bigger, but in the meantime I'd like to get some stick time in before next Saturday. I bought 2 battery packs in hopes of charging one while flying - so can I cannabilize these babies and make a 6 or 7 cell pack? I'm quite adept with a soldering iron, and I know not to get the NiCad too hot. But other than that does anyone have any tip/tricks/comments about this approach? I've got a masters in Electrical Engineering, so I should be able to figure out the series parallel thing and keep my pluses and minuses straight - although my smooth move at reversing the polarity when initially hooking up the ESC my not completely support that assertion.
On the other hand, we have Batteries Plus in town, and while that's probably not an ideal permentent solution, do they carry LiPo cells? I've got the Great Planes ElectriFly Triton DC Comp Peak Charger, so I can handle charging LiPo (although it is unchartered territory for me), any advice on building a LiPo pack?
Thanks
Reply to
eric_amundsen
Easiest to switch to a 7 cell Nicad or Nimh as the charger will need an upgrade for LIPOS.
Just get a 7 cell pack of similar capacity to what you have - that upgrade alone turned a barely flyable model into one with more than adequate power on my first electric model..
Buggering about with pre-made packs is non trivial - need a big iron and sometimes specialised bits for it.
Once flying, join the ezone
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for much more information on best upgrades when you have time to get to grips with it all.
Reply to
The Natural Philosopher
Just a quick word about Lipo's. Please do your research in chargin
these puppues. They do require special care. While I'm not an oppone of Mr. Dave Brown's histeria, I do take precautions when charging them. Error on the safe side. N/P is correct in that a 3s would really tur this model on
-- starca
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Reply to
starcad
On 9/24/05 11:32 AM, in article snipped-for-privacy@g49g2000cwa.googlegroups.com, "eric snipped-for-privacy@yahoo.com" wrote:
Did you check balance and move things around to get it right? How's the motor thrust set? How does the plane glide? If it won't glide well, it won't fly well.
I read all the other posts, and I suggest that more power is not a good first response to your problem.
Don
Reply to
Don Bowey
Thanks for all the advice, including the "is your computer plugged in?" type. Yup, my prop was on the right direction, my CG is in the right place, and all the control surfaces move in the right direction and the motor thrust is OK - but it doesn't hurt to check these things out. I got out my trusty iron and built a 7 cell pack out of my two 5 cell packs the stinker jumped out of the hand. Now if the weather will just calm down a bit I can get some stick time in. I'm definitely going to look into tweaking my power plant parameters (# cells/capacity/prop), but at least I now have a baseline to work from.
Reply to
eric_amundsen

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