can773
Posts: 1637
Joined: 1/25/2002
From: Calgary,
AB, CANADA
Status: offline
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quote:
ORIGINAL: VinnieK
If you're truly interested in flying electric pattern, the first thing to do is search on "electrified partner" in RC Universe. It's a thread started a couple years ago by Tony Frackowiak on how he constructed an electric PL Products Partner. Read the whole thread because it's loaded with info that's as good today as when it was written. The only real thing that's changed since then is that the lipos have gotten lighter and more powerful.
I spent the last month flying with Andrew Jesky and Peter Collinson in preparation for the Nats. After the second day, I knew my next pattern plane would be electric. Since then, I've been gathering as much data about it as possible. The majority of what I've learned comes directly from watching and occasionally helping Andrew and Peter. In no particular order, here's a list of observations I've made:
1. For power, a Hacker C50-14XL, Hacker Acro 90 speed controller, APC 22-12 electric prop, and Thunderpower 5S-4P 5300 batteries will give you more power than anything out there, glow or electric. There's one maneuver in the FAI schedule that convinces me this is true and my judging assignment for FAI at the Nats convinced me even more.
2. To be able to realistically practice pattern with electric, you need a minimum of 4 batteries and 6 would be better ( it takes two batteries per flight).
3. Field charging batteries is a primary consideration. If you don't have the ability to charge 4 packs at a time, you'll end up waiting a long time between flights. This means you either need 4 chargers or 2 chargers capable of charging 10S packs (2 5S packs in series). All the chargers I've seen run off of 12 to 13.5 volts DC. That means your car battery but only if there's always someone at your site that can give you a jump start when it's time to go home. Other options include a deep-cycle marine battery that you bring along (heavy and awkward plus it's something else to charge each night) or a generator. The Honda EU1000i is a lightweight (26 pounds) generator that only puts out 56 db at 900 watts continuous/1000 watt surge. The street price on that is $750.00 but a little shopping on EBAY will get you one for about $500.00 or so used or $629.00 new from an EBAY vendor.
4. If you go the Honda route, you'll need two power supplies capable of running two chargers each. That equates to an 18 amp power supply. Forget the Diamond power supplies. They overheat and shut down. There's a guy on EBAY that sells a 20 Amp (18 Amp continuous) power supply for $59.00 and he'll reduce the shipping charge if you buy two of them (you need two). Look for him in the Hobby R/C section on EBAY. However, these power supplies may not be adequate depending on which chargers you select. If you use Astro 109 chargers, the Honda and the above power supplies will work just fine. According to the specs I've read on some of the other chargers, the power supply probably won't cut it.
5. Andrew already discussed the cell balancers and that just makes sense to me given the cost of a battery pack. In fact, the cost of a pack has me thinking a seperate charger for each pack makes a lot of sense. If something goes wrong with a charger, you only lose one pack instead of two!
6. The weak link in the whole setup is the gearbox on the Hacker. I witnessed Andrew's implode and the aftermatch was pretty ugly. These things need regular, documented, maintenance. Every 50 flights or sooner if necessary. I tracked down Tony F at the Nats and he showed me what to watch for. Tony rotates the prop each way by hand to "feel" the gears. If it doesn't feel the same, he pulls it out for service, regardless of the number of flights and opts to let Hacker clean and grease the gearbox for him. Hopefully, he'll see this and respond in case I got anything wrong or left something out.
7. From what I've read and seen, Plettenberg and AXI outrunners are starting to appear as viable alternatives, but cooling seems to be an issue since they sit so close to the nose of our planes. In addition, there's still a lot of experimenting on props going on with those two motors.
In case you haven't figured it out by now, I'm planning on going electric next season. My shopping list has already started and I actually have the power supplies, speed controller and the Honda. Yet to purchase are:
1 - C50-14XL w/ 6.7:1 gearbox
4 - AstroFlight 109 chargers
4 - Thunderpower cell balancers
1 - Raytek MT-4 Tempgun
1 - AstroFlight Wattmeter
1 - APC 22-12 Electric prop
6 - Thunderpower 5S4P 5300 battery packs (I'm making this my last purchase late in the winter in case something better comes out)
Anybody want to buy a 2003 Harley Dyna WideGlide in great shape....... ;> 
Verne Koester
Hi Verne
Couple of things :-) If you are truly serious about going "green" for next season I think you will find that it will be best to wait until the last possible minute to purchase. Hacker already has a new motor, as well as a controller with an "F3A Brake" (I have no other details) that the Matt's will be using in France (probably others as well). Next spring I would imagine everything ran at this years Nats will be obsolete 
I know that the new TP charger is due out shortly which is probably the best bang for the buck ($180 for a 220W charger, the equivelent Schulze will run you around $400). 2 of the TP chargers will charge as fast as 4 109's and will be cheaper, plus they are smaller. The other beauty of the TP chargers is it hooks to their balancers to shut down the charge if ANY cell exceeds 4.24V.....IMO this is a MUST have safety feature. Unfortunately this will only work with the TP charger.
On to the balancers, within a week or so the 10 cell balancers will be out allowing safe series charging on every charge without voltage checking (and taking your balancer numbers from 4 down to 2). The other issue with the Astro's is they wont charge 10s, only 9s.....so if you ever want to charge a 10s pack you will be out of luck.
Power supplies, 18A is not sufficient for 10s charging (we have tried, 4A charge rate is the max)....you need around 25A to make a go of it for 1 10s pack, 45A if you want to run 2 chargers with 10s packs (this is assuming you are charging at 1C...or 5A for the 5300's). Its all in the watts,....at best the Astro is a 140W charger, while the TP is 220W, so whatever you use the best bet is to have a power supply that can deliver 10-15% more watts than your charger can consume (to account for losses). So to run 2 TP chargers a true 500W (40A@12.5V) supply would be the minimum I would use. I would probably go for 600 or 700 just to reduce the load on the supply.
quote:
7. From what I've read and seen, Plettenberg and AXI outrunners are starting to appear as viable alternatives, but cooling seems to be an issue since they sit so close to the nose of our planes. In addition, there's still a lot of experimenting on props going on with those two motors.
I think you will find that the new motor from Plettenberg is pretty much on par with the Hackers (and who knows what will be out by the spring), plus there is also the Cyclon outrunner but I have not seen this run (they will be in France). Cooling is tricky but my motor ran no hotter in Muncie than any of the Hackers and in some cases it ran cooler. There were days it was running down around 125F, while I heard of Hackers up in the 150F range. The Plett that I ran in Muncie mostly was the 25-13, that is pretty much a proven setup. I use the 19x12W prop and peak current in the air is 60A, dont know if you judged either Adam or I, but typically we are not at full throttle more than once or twice during P-05. I have 200 flights on that motor without ever looking at it once (no gearbox!)....IMO the Hackers gearbox makes it no more reliable than a glow motor....I know that I never had to remove my 140DZ engine every 50 flights to work on it so that it would not implode!!
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Chad Northeast
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