Giant Scale TF P-47

[jeffsr01]

OK, here is the challenge question for 2008. I have been doing gas and glow since the dinosaurs died out. I have been watching the recent improvements in motors and batteries. Anyone have suggestions for Top Flight Giant Scale P-47. Will use seperate packs for servos/receiver. I don't care about weight per se, just would like to know if there is a setup that can pull this puppy thru the air without needing a 1/2 mile take off roll. I have always used NRG Research props. Had a 24" wheel (4 blades, adjustable pitch) in mind. I'm not looking to blister the paint, just something near scale speed and your basic warbird manoveurs. As a guideline, I would otherwise be putting a Zenoah G-62 on the Firewall. Let me know if I'm nuts or there is a setup that might fit the bill. Thanks in advance. Jeff..

[Ron101]

There are many motors that would pull this plane great..

I'm running a nue motor 1521 geared inrunner motor with 12s 5000 mah pack
it my 30% extra 300 .. it has a 87 inch wing span and weights 18 pounds..
it puts out 4100 watts which is about 5.5 hp ... that more than a DA 50 or a G-62.... It will hover at half power..

You could also look into large outrunners... lot of ways to get it done

Here is a pic of my plane and setup

Good luck!!
Ron

[portablevcb]

Jeff,

Your need is only limited by dollars. You can have blistering speed, vertical performance, or scale, depending on the power setup. Electrics are far more advanced than you might think. Heck, there are a couple of full size planes on electric power now.

I would call or email my favorite mfg and ask them what they recommend for the performance desired. EFlite has some motors labeled for their glow equivalents (eg, EFlite Power 120) and most of the mfg web sites list comparable 2 stroke engine sizes with their specs.

charlie

[frankswd]

Jeff,
I love electrics. All my planes are electrics right now. I'm getting a Skyshark P40 with 82 inch Wings and I just couldn't get my cheap self to go the 3X factor to make it electric. I will be interesting for me to see what answers people bring up and IF they can make it "cost effective" I found a DL50cc for less than $400 that could easly expect to fly for 10 minutes on a tank. That's the cost of the Batteries along to go electric and fly for that time span. If you have a 34volt system under load and want 5 HP that's about 3.8KW not including losses, you need a system running a constant 112 amps. So to get your 10min or so of flight you will need a battery of at least 10,000 amh. Most big lipos are 5000mah, this leads to a pack that is 10s2p or 4 batteies of 5 seriesed @ 5,000mah. Next you will need a speed controller that's rated at about 120amps, I wouldn't use just a 100amp rated speed control unless it came for some well known vendor like Castle Creations (like thier HV110) it MIGHT not be able to cool itself well enough due to internal resistance of it's design. Choose this part wisly it keeps your batteries from over discharging and you motor WORKING. Then you need a motor that can handle the watts. THere are lots of motors in this range 3-4 KW, these days, Skyshark actaully has one on sale for a good price. I expect it's a good motor but I have only used Steve Nue and AXI motors in my higher power stuff. It will add up quickly. Do it for the fun of it, yes! The equipment is there to make it happen. IT will be a crowd pleaser, but it's going to come at a cost :) A lot of the BIG power system flyers out today are sponsered to some extent I believe. Good luck and Keep'm Level!

[staggerwing]

I disagree on having to spend a lot of money --shop around, no need to buy top shelf equipment unless you're going to compete in aerobatics or just think you need high priced toys.
I have two large scale elec birds, one @ 8' & 22lbs & neither drive train (mtr plus controller) cost me over $225 less lipos. The (2) 8c 4s 6600 mah lipos I use in series & swap between both planes came from Jun @ XUS & were on a sale clearance--total $150.
Give the guys at BP Hobby a call or e-mail them--they are an excellent honest ref. to help define an application.
It all depends on what you're flying, how you want to fly it, & if you're willing to bypass the glitz of high priced items & shop around.
There is of course the peripheral equipment to consider---charger, balancer, etc., that can be picked up used .
Take your time if possible ---most of the best info I've found is from the input on this site.
Bob

[frankswd]

Certianly clearance sells would help. And dropping your power expietations would help a lot too. 8C 6600 mah lipos are only rated for 53 amps, and your only going 8S. Have you put a watt meter on your system? Anyway, this guy is used to 50cc motor and so expects 5hp or so of power. And that's what I was specing on. Your system cannot be delevering that kind of power safely. It is impressive that you feel you have enough power to fly a warbird comfortably on that setup, that says a lot for the difference between electrics and gas maybe? And you are right i did leave out the support equipment (one time investment type stuff) thanks. Be cost effective but not cheap!

[staggerwing]

OK Frank, thks, I'm new at this hobby.

I can forsee this becoming one of those " anaylsis paralysis " threads--

My last input
---Charlie--all of the components I mentioned were purchased new--retail USD dollars---only the lipos were on sale. If you're not "stumbling across these bargains", you may be just stumbling, but you ain't lookin.

[portablevcb]

For those of us watching this please use retail dollars, not used or clearance prices. Yes, we all stumble into good deals every now and then, but, they usually don't happen when I need to order :)

For power, electric does respond a bit differently, especially at partial throttle, so direct power comparisons are not always the best way to compare unless you want just top speed performance. Would like to see setups folks have in similar size and type planes.

charlie

[fbw4]

Here's a system I am using in a 30% Yak-54.

Hacker A60 18L
Master 99 ESC
12S-5000 Lipo's
24x12 apc-e Prop

This system will fly your P-47 with authority. The system cost 1069.99 for everything including the mount. The motor and controller cost about what your gas engine costs you just have to pay for all your fuel at one time.

http://www.aero-model.com/powersetdetails.aspx?id=eps50

[portablevcb]

Thanks. That kind of price is what I was looking at for another project.

charlie

[frankswd]

Yep, now that's a setup that will work and price i would expect, nice deal they cut $200 as a package, not bad ;)

you might want to consider getting a second battery pack setup however so you don't have to wait for the recharge to fly again.

[R/C Dallas]

You can easily cut another couple hundred dollars off fbw4's price quote by using A123 cells vs. top shelf LiPos. Your P-47 can easily absorb the extra weight associated with A123s and you would get the many benefits of these great batteries. i.e. fast charges, high cycle life, not a fire hazard etc...

[frankswd]

The A123s are an interesting new player, my charger doesn't work with them but if he's going to buy a new charger i guess that's no extra cost to him. How much would it cost to get the same maH capacity? do you have a link to a good deal?

Hey Jeff you still listening? still game to play?

[R/C Dallas]

14S2P (28 A123 cells) would be equivalent to 12S 5000 LiPos. It would actually give you about 600 mah more useable energy compared to the 5000s if you use the 80% of capacity for LiPos as recommended to extend your battery life. You can use the entire 2300 mah available from A123s without harming or shortening the life cycle of the battery.

As far as where to buy...ebay has been the best place to pick up these babies. You can usually get a 10 cell 36V dewalt battery pack for around $100 or less delivered. 3 packs costing around $300 will give you 30 cells total where the extra 2 batteries could either be held as spares or you could use them to power you receiver and servos. A 2-cell A123 pack makes an excellent receiver battery! Lots of info on A123s in the battery forum.

[sajeev]

You can easily cut another couple hundred dollars off fbw4's price quote by using A123 cells vs. top shelf LiPos. Your P-47 can easily absorb the extra weight associated with A123s and you would get the many benefits of these great batteries. i.e. fast charges, high cycle life, not a fire hazard etc...


where do i get these batteries ? A123 i mean. do you mean they do explode, catch fire etc ?

[kelberts]

They are in 36V Dewalt packs (on Ebay) or in ready made packs at MEC

http://www.modelelectronicscorp.com/view_products.php?tid=1&stid=2

Way safer than lipo. Hard case like a nicad. No burning, exploding, etc. plus if you crash, you probably won't hurt them, unlike lipos,.

I use 8S in my 72" P-40, 6S in my Sr. Telemaster, and 12S in my 55" BAE Hawk EDF

[frankswd]

Who makes that nice P40? I have a TMS as well ( before ARF version) Love that plane:) and just bought a Skyshark P40.

[Vintauri]

They are in 36V Dewalt packs (on Ebay) or in ready made packs at MEC

http://www.modelelectronicscorp.com/view_products.php?tid=1&stid=2

Way safer than lipo. Hard case like a nicad. No burning, exploding, etc. plus if you crash, you probably won't hurt them, unlike lipos,.

I use 8S in my 72" P-40, 6S in my Sr. Telemaster, and 12S in my 55" BAE Hawk EDF

Whats the weight of your P-40? I'd be interested in more details as I'm working on a 70" Hellcat and trying to settle on a power system with A-123 cells.

Thanks for any tips.

Steve

[ramboman]

The A123s are an interesting new player, my charger doesn't work with them but if he's going to buy a new charger i guess that's no extra cost to him. How much would it cost to get the same maH capacity? do you have a link to a good deal?

Hey Jeff you still listening? still game to play?

About a123:
- you need only ONE pack because you charge in the plane within 15min;
- no commercial charger is appropriate, I use Mastech HY5020E;
- you need a generator or battery/convertor;
- weight is 500g more than LiPo for 12s2p, price is far less;
- don't forget to balance them at night with a 12s balancer (not two 6s).