System advice for 92" Hurricane

[ALEX HEWSON]

Hi fellow large electric folks :D

My father and I are planning on building a 92" Hurricane which we estimate will be around the 25lb mark.

So getting to the point, we would like to find an affordable power system for it, that also enables us more than one flight a day running two chargers.

So what I would love to see now (well wishing anyway ;) :p :D ) is a flood of replies detailing motor, esc, battery, prop combinations that would suit a moodel of this size. Keeping in mind that a good 10 minute flight for F4C scale competition is required and our pockets only go as deep as our fingernails :p :D

Alex

[Andrew McGregor]

A123s sound the way to go for batteries.

[dlinegar]

I guess the operative word is "affordable". Depends on what you mean by that.. Many options exists, but are not going to be cheap, if you know what I mean. So what's your budget for $, weight, power and duration?

Cheers,

-derick-

[GregG]

A123s sound the way to go for batteries.

I was thinking the same thing. However you'll probably have to do a few parallel packs.

I've been wanting to build my 94" Corsair for a long time now. The A123's are probably the way it'll be powered. It's been looking like 10S4P should just about do it well. :D

[ALEX HEWSON]

Well absolute budget for power systems is $2000NZD ($1500USD).

Maybe the A123s are a viable option. We shall see.

[Andrew McGregor]

Motocalc likes a Hyperion Z5045-18 on 15s3p A123 driving an 16x16 4-blade prop a lot, so long as you can keep the model below 11kg. That's close to NZ$2k from RCBandit, depending on what price you get for that many cells (hopefully less than $30 each). Heaven only knows what charging them is going to take though... probably just a long time in blocks of 10 on a 1210i (or however many of those you want to buy).

[R/C Dallas]

Austin at MaxAmps was selling 10,000Mah cells for $25 per cell a few weeks back. You might want to check with him for an alternative to A123s. Myself, I went with A123s for a 94" Extra 300L which I hope to bring in under 20lbs. $344 for 3 Dewalt 36V packs off of ebay. Quick charge and 1000+ cycle life as well as the low cost were the deciding factors for me.

The Hyperion Z5045-18 and Hacker A60-18L motors have been proving good for 4kW which should be plenty of power for a warbird of that size. So the next question is the prop. The 16x16 4 blade mentioned above sounds a little small for that size of plane but the numbers are probably close to what you'll need. I plane to use a 26x15 2 blade on either 12S2P A123s or maybe 13S2P if the motor can handle the amps. But that is slow aerobatic flight vs. scale warbird flying...you'll want more speed for those scale on the deck high speed passes.

Good luck

Randy

[Andrew McGregor]

Well, I did some more numbers... and noticed that a scale prop for a Hurricane is a 3-blade.

18x18 3-blade on 15s3p A123. How does 177kph level and unlimited vertical at 70kph sustained sound, with the magic 10 minutes duration so long as average throttle is below 75%?

[R/C Dallas]

Those numbers look quite good. What was the input watts and current at WOT with that setup? The only other thing I can think of is you will need an ESC capable of handling 15S A123 (54vdc unloaded). A Jeti SPIN 200 is good for 15S LiPo but is expensive. And the Jeti SPIN 99, CC110HV and Hyperion Titan 90 opto are only rated for 50V or 12S LiPo.

[Andrew McGregor]

Aargh, my browser ate my post...

About 3800W, 91A at peak in flight, 5800 RPM on the prop.

Noting the voltage limit, and realising that 12S3P is that much easier to charge (6 blocks of 6 instead of 9 blocks of 5), not to mention cheaper, I went looking for a 12S setup.

That gave a 21x25 3-blade (closer to scale, a true scale prop for a 92" Mk I Hurricane would be a 26x51 2-blade, and I presume a similar 3-blade for the later models). Although it doesn't have the insane vertical, it still performs great; the same 177 kph, best climb rate of 14 m/s at a 50 degree angle. All on 3430W and 105A, which is within range for a Phoenix 110 HV, and even within the burst rating of a Hyperion 90 HV, although that's probably pushing it.

[mexico]

Austin at MaxAmps was selling 10,000Mah cells for $25 per cell a few weeks back. You might want to check with him for an alternative to A123s. Myself, I went with A123s for a 94" Extra 300L which I hope to bring in under 20lbs. $344 for 3 Dewalt 36V packs off of ebay. Quick charge and 1000+ cycle life as well as the low cost were the deciding factors for me.

Randy

Randy -
In what configuration will you run your A123's for your large Extra? What will you use to supply necessary power to quick charge (3C) those large relatively high voltage packs? I am shopping for a new power supply and would like to get something that will be up to fast charging A123's in the future.

[Andrew McGregor]

It's really hard to beat a diesel truck as a field power supply... mine has a huge battery capacity, 150A alternator, 2L/hour idle fuel consumption, and cheap fuel.

[ALEX HEWSON]

Aargh, my browser ate my post...

About 3800W, 91A at peak in flight, 5800 RPM on the prop.

Noting the voltage limit, and realising that 12S3P is that much easier to charge (6 blocks of 6 instead of 9 blocks of 5), not to mention cheaper, I went looking for a 12S setup.

That gave a 21x25 3-blade (closer to scale, a true scale prop for a 92" Mk I Hurricane would be a 26x51 2-blade, and I presume a similar 3-blade for the later models). Although it doesn't have the insane vertical, it still performs great; the same 177 kph, best climb rate of 14 m/s at a 50 degree angle. All on 3430W and 105A, which is within range for a Phoenix 110 HV, and even within the burst rating of a Hyperion 90 HV, although that's probably pushing it.

That's sounding good, Andrew. Will have a chat with you about it next time I see you.

What we are after is a scale speed though you see. So more around the 130-150kph mark.

Will give this thread some time though first to see if any other advice etc pops up ;) :D

[Andrew McGregor]

Well, I went all the way to scale diameter... which can work, giving a top speed around 150 and decent duration.

Remind me to bring my laptop sometime so we can run the math.

[Heather]

You would be best to do the majority of the building before investing in the power system. Then you will have a much more accurate weight prediction and on a project of that size I would think 6 months or more will have passed so technology and prices will have moved on.

Heather

[ALEX HEWSON]

Correct to the exactness, Heather =)

We won't be purchashing in the next 6 months thats or sure. But just wanted to start te ball rolling on options and ideas.

Will be looking at a speaker system like on Ians Corsair also

[Heather]

That sounds great Alex, is the hurricane from a plan?

BTW Ian now has the dealership for the Sound system for NZ so we can help you with that part for sure.

Heather

[ALEX HEWSON]

Yes it's from a plan so we will be building as light as possible ;) :D

Awesome! My dad will be glad to hear that :cool: :)

[Franz2002_01]

take a look at www.unitedhobbies.com and buy A123s from Ebay. I would assume you would want to power at around 120W/lb (i. e. ~3.000 Watts WOT). Using 30 Volts as a guidance you are looking at 100 Amps load. 3 Dewalt A123 packs will cost you about $330 on Ebay. The ESC from unitedhobbies will cost you around $90 + shipping (which is good for 15S A123s and 100Amps so your 10SA123 setup will work). As a motor either get yourself a more efficient NEU for about $600 or get an AXI5330 for about $250 or a cheap copy for about $100 (one of the HXT's from unitedhobbies) - efficiency goes up with price. Overall you are looking at spending between 500 -1.000 for the powersystem).