dreadnaut

My Feedback: (5)

I have decided to go electric and start pattern flying again. The full monty Hacker setup used by QQ etc is out of my budget. I can go to an 8 cell set up and have looked at both of these motors so far. I intend to scratch build and want to know if any one has had experience with what would be the optimum weight for these power sources.

Thanks

wk9000

I stumbled on a research paper about low reynolds number electric aircraft, and here are the numbers they had. This would
be optimal as in rocket science optimal. Motor 7% (of total weight). Airframe 35%. Fuel and avionics 58%. So, thats one benchmark
for whats possible. Geared hackers I think come in around 9%. I think motor weight is a quick way to tell if a motor
is about the right size and then look at prop data for your plan. If a motor is too small it'll get real hot... and a few ounces
over on the motor is probably a better 'buy' than extra ounces elsewhere. I use Axi/thunderpower/jeti but now I
am looking at the others, for fun also but I don't like the geared ones, although they have superior power/weight and
efficiency.

The most obvious thing you can do is look at what else is flying with the motor and what the prop data is (size, speed). The hyperion
330 flys well 3d with a light battery with the 4130. I saw a video of the great planes gee bee (60-90) flying very fast with the 4130
and big batteries but I think more wing area would be welcome from my perspective.

Watts don't lie, so multiple volts and amps and efficiency and look at those numbers vs weight. Compare those with the f3a numbers
which are carefully specified. They are around 220 Watts per pound, I think... exact number if you run voltage a bit
high and a larger prop you can get huge burst power buts its quite hazardous to your investment.

As for cost, I recently found united hobbies and they have some decent gear, servos, speed controls and motors and lipos. If any
of these are suitable that could shave some significant dollars off.

You might fly the first plane as an arf... that tells you stuff about weight and power and, well an arf lost is less stress. I'd noticed
great planes minnow flys well and is about a 90, and around $220.

Nice id picture, by the way. Look at a balancer and a charger that gives you mA charged. I also got an astro flight power
meter- I think you have to have it to get the loads right, otherwise you either don't get the power you need or you burn things
up completely. I like the idea of copying a rig you have seen fly a number of times.

I'm not sure where I'd get a 90 size pattern kit. I did investigate the CA Zaphiro kit (299) Aeroworks.com has it. Very decent
glass kit. Its just a bit bigger than the 4130. It would be a 5320 but might be 8 cells.

Espritmodel.com gives airframe only weights on his web site- very helpful and also has some video's of the planes flying
electric (rc universe has its share of video's too). Doing this you can see somewhat how very different a plane flys when
the airframe is over or under weight.

Oh- your question, weight. I'd guess 7 1/2 lbs, but look at the Fliton 330 at the esprit model website.. see the video. They have
the airframe weight published and the exact battery/motor. That is fully 3d, though for pattern I like a bigger plane.

--

patternflyer1

My Feedback: (11)

The 4130 is a great motor. I'm sure the eflite is equally as good although I haven't seen it in action.

Here is a video of the 4130 in a Fliton Inspire
http://media.putfile.com/Inspire-60-Video

This plane fly's on a 6cell setup I believe.
I have the mini version that fly's on 3 cell. Still have to get this one someday. Too busy paying for the "full monty" stuff as you call it.

As for weights used with this motor, goto www.modelmotors.cz
Lookup the motor you like, or use their ez calculator..

Here's a setup that's relatively inexpensive. Buy an Evolution from Ultra-rc (430 bucks) Full 2meter.. Buy an Axi 5330/F3A, or an Eflite 160, or maybe a dualsky motor. They're like 220 I think. Buy a Jeti 90. Like 250 I think. Then your 10 cell packs run anywhere from 400 to 700 a set. If you are flying in a beginner class you can get away with less mah's obviously. I fly Masters (limited by battery at this point) and use 3700 mah packs. They run like 440 per set. I have 3 set's.

Not sure what your budget is, but this setup wouldn't be much more than the 8s setup and a good scratch build.

Any q's on your new electric adventure, feel free to pm or email me. I'll be glad to help..

Chris

dreadnaut

My Feedback: (5)

Lots of good info, thanks!

I currently have an Exceleron with a YS.110. Unfortunately, the area I live in is pretty hilly, and in the last fifteen years, nearly all of the flat spots sutable for RC fields have become a golf course, shopping mall, or wild life sanctuary. We used to fly off a costal salt marsh. No more.

I do not really object to the wild life thing, since it helps keep out the golf course and shopping mall traffic.

There are a couple of club fields within fifteen miles of home. One, the flight line faces the sun. At the other, one end of ''the box'' is over an interstate. I cant practice there without the safety guru coming down on me.

Electric will give me more options. I have flown every day this week with an 480 powered Aeroworks Stingray at a small field I pass on my way home. It is just big enough for a .90-.110 sized plane too. I have flown at the beach, early in the morning before the wind picks up and the Zagi crowd shows up (dooood!)

I was thinking of designing to hit about 8 lb. I think it should be OK since I do not treat the throttle as an ON/OFF switch. Of course I want to build light the get the most wing span.

I will shoot for 7 lb, so that I wil have the ability to add balast for windy conditions. I did the math a while ago to get an approximate wingspan, just have to find it somewhere.

dreadnaut

My Feedback: (5)

Since I am looking at having multiple packs, probably 3, the price of the batteries is the determining factor. I would love to run a 10 cell setup. My wife can't understand why I don't just use my current 3 cell setup.. I will be flying intermidiate, so an 8 cell will probably be competative.

nwc

Here is a combo I am flying. Venus 11, Axi 4130, TP 7s 6000mah pack (1 3s; 1 4s in series). this combo is good thru the intermediate pattern.
I have not tried anything beyond these maneuvers. The Venus 11 is an excellent airplane to convert to electric. The batteries fit in the belly
pan. All you need to do is make the belly pan removeable and you do not have to remove the wing to change batteries. If you want to fly the
more aggressive patterns you need a lot more power,ie, Axi 5330F3A, 90 amp esc, 10s batteries. Cost goes way up. Hope this helps.

eflier

another option for the Venus 2 is the eflite power60 on 6 cells...16X10 APCE prop
lotsa power through advanced...Also the EVO 3700 cells don't have to be used in a parallel setup, so that you save on the battery cost....and weight. model weighs exactly 8 lbs with this setup.