88" Extreme Flight Yak Power system questions

[K0na_stinky]

Hey guys, I’m considering getting into large electrics. Right now I’m flying a 60” Sebart Sukhoi 50e. I’m flying with a 6s 3200 battery.

I am thinking about a Extreme Flight 88” Yak 54.

I have some questions about the power system.

Will a 30c 12s 3200 battery be big enough? Smallest I have heard of every one using is 10s 4500.

Any idea of run time on a pack like that?

Will a Axi 5345/14 have enough power for unlimited vertical? (I’m used to a plane with 250+ watts per pound) I can settle will about 200 watts per pound, I think….

I’m thinking about using a Castle Creations HV 110 ESC.

Any ideas, suggestions, anything?

Thanks a lot.

[tIANcI]

KOna ... 2,000W for that plane is not going to give you unlimited vertical. You are going to touch about 15 lbs on that plane. Hence, its a pulling a mere 133W/lb.

The CC110 would be lovely for sure and a 12S set up is just nice. However your proposed system will be pulling 60A WOT at the very least. Your packs will not last you more than a 5 min flight if you are cruising about only, let alone enjoying those unlimited verticals.

With the smaller packs you will have CG issues too, you will want a fair bit of weight up front. Remember, a 50cc gasser is about 3.75-4 lbs lbs with muffler, standoff and the EI unit. Your motor with standoffs is about 1.75-2 lbs.

Try the Hobby City Rhino packs if you can, they are pretty decent and very affordable. Get the 4,900 mAh packs.

[K0na_stinky]

I'm not sure where to get info on these motors. On tower hobbies it says it can turn a 22 x 10" prop and can be 110 amps for 20 seconds. 3D planes up to 17 pounds.

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXPPY6&P=0

I'm starting to think a 74" yak would be a better idea on my 12s 3200's.

[172AMD]

KOna, Do a search on "happyloop" this guy has a thread on the 88" Extreme Flight Yak 54. Lower kv motor, larger prop, and larger capacity cells [than what you are proposing]are what this guy and others seem to be using on these/type planes. There is alot of info on this site about these sort of conversions!
I agree if you want to stick with the batts you have, the 74" yak is a better choice.

Dave.

[K0na_stinky]

Thanks very much for the info Dave.

[baykah]

I use 12S5000 on mine => Hyperion Z5045-18B @ XOAR 24*10-E @ 70A ~3200w
Pull of a torque better than a DL50, flight time approx 8min with 20% left in batteries.

Batteries weight = 1,5kg

Plane ready to flight ~8.5kg

~376W/Kg

[K0na_stinky]

So I could use the the 12s 3200's but the run time would be around 5 min. Thats alittle short for me, I think the 74" is the plane to get for my batts.

Thanks again for the info guys.

[parkfly27]

I think that, if you get a motor with slightly lower KV (150-ish) with those batteries you should be able to turn a 24X10 at 6000 RPM on 85 amps, which would be great for 3D. Still though, you can only hope for 6 minutes max of 3D type flying. Also, the batts would have to be right up under the cowl next to the motor (or at least right behind it).

If you average 10C (which is 32 amps with that pack) then your flying time will be six minutes at 1408 watts average. This is about 88 watts/LB on a 16-pound airplane. From my experience, hovering takes about 110 watts/LB, so i think this 6-minute flight time is pretty realistic. Still though, you should probably be safe and keep it to 5-minutes max. LVC while hovering can ruin a good day :rolleyes:

If you really want the 88-inch yak, maybe this video will help? He is using a 180-KV motor on 10S lipo. Not sure what size prop though. You can get two 5S 20C 5000mah lipos for $73 each over at hobbycity (if they ever get back in stock) and just wire them in series.

Oh also, i think the thumper motor brand in that video is the same as the HXT brand at hobbycity.

http://www.youtube.com/watch?v=RmGpaSmaEVY

Hope this helps some :)

[K0na_stinky]

Thanks parkfly27.

I have watched that video many times... lol

That is the video that got me thinking about bigger planes. But a 5 min. run time does not appeal to me.

With one 6s 3200 I can get over 10 min of mixxed flying in my over powered 60" plane.

Still thinking about the 74" tho.

[parkfly27]

you're very welcome.

Well what a coincidence :cool: yup, that's a great video. Got me thinking about (and buying :eek: ) large electrics.

I think that the 10S setup will give you 10-minutes of mixed flying on the big one. However, the smaller yak would be perfect for the two 6S 3200's.

[K0na_stinky]

Since when is a 74" plane small?? lol

At my club they didn't know what to say when I pulled out my 60".

Well one guy after his first glance said "ohh so your running glow planes now?".

Our club is mostly 40" electrics and 40 size trainers.

[parkfly27]

Since when is a 74" plane small?? lol

At my club they didn't know what to say when I pulled out my 60".

Well one guy after his first glance said "ohh so your running glow planes now?".

Our club is mostly 40" electrics and 40 size trainers.

lol, notice i said the 74-inch plane is smaller ;)

I have mostly parkflyers (don't know how one would guess that :p ) and one 63-inch sport aerobatic airplane (electric). Where i fly at the university, the 63-inch plane is usually the largest airplane there (weight wise anyways).
My next project is a 96-inch yak-54, and will be electric. I just need to buy, or build, a fuse for it. At 17-lbs, it should be a real floater.

good luck with your yak, whichever size you choose!

[K0na_stinky]

lol, notice i said the 74-inch plane is smaller ;)

I have mostly parkflyers (don't know how one would guess that :p ) and one 63-inch sport aerobatic airplane (electric). Where i fly at the university, the 63-inch plane is usually the largest airplane there (weight wise anyways).
My next project is a 96-inch yak-54, and will be electric. I just need to buy, or build, a fuse for it. At 17-lbs, it should be a real floater.

good luck with your yak, whichever size you choose!
Your building a 96" yak thats 17 pounds?

I think I want in on that. Whats the info on that plane? What are you going to use for a motor, esc and batts?

[parkfly27]

I just got the wings, rudder, and horizontal stabilizers for a 1/3 TOC Aviation yak. I checked the weight for all of these components, and it's 6-LBS. I started adding everything up (motor, ESC, servos, battery, fuse, ect) and I can't see how it will weigh any more than 17-LBS. Here's what i will use:

Turnigy SK 63-74 outrunner
2X zippy Flightmax 5000mah 5S 20C (in series)
Turnigy sentilon 100A HV 10-12S
some sort of UBEC or 2S lipo with voltage regulator.

I'm hoping it will turn a 28X12 at 5700 RPM, for 32-LBS ish thrust at 3500 watts. I'm a 3D flyer, so i'm not interested in speed here, but more prop hanging instead.

However, this is just speculation. :rolleyes: The airplane may turn out much lighter or much heavier, we will have to see. I'm actually sort of worried it might be too "floaty" at 17LBS.
Check out my thread in the giant electric aircraft section for the build. I don't think much will happen with this airplane untill summer, with the fall semester coming to a close soon.

I have heard of someone building a ultra-light yak from the carden "baby yak" kit. I bet that, if you cut some of the un-necessary foam out of the wing and tail cores, go easy with the sheeting, and put in a light electric power system, you can probably get in the 17-lbs range.

If you can find some plans, scratch-build is also a possibility. I'm just very bad at building wings, which is why i was so happy when i got the deal for these parts.

Best of luck to you!

[parkfly27]

hey K0na_stinky, did u figure out which yak to get? I really haven't made any progress on mine. It's looking like 17lbs is pretty realistic tho.

[K0na_stinky]

hey K0na_stinky, did u figure out which yak to get? I really haven't made any progress on mine. It's looking like 17lbs is pretty realistic tho.
I'm starting to think I should just man up and buy some new batts. I really want a 88" plane. I want something that will take a good amount of wind without troubles.

So as of right now I'm thinking, CC 110 HV ESC, the new Great Planes "65cc" Rimfire motor, HYPERION 25c 6s 5000, or 35c 6s 5500 packs and Futaba S9157 servos (425 oz-in).

Your looking for a fuse for your plane eh?

[parkfly27]

i have never seen the 65cc rimfire, must be really new

6S at 100 amps will pull that plane like crazy. Can't wait to see how it works.
If you wanna save some $$, the flightmax zippy batteries are very good, and only $90 for a 6S 5000 i think.

I still have not found a fuse for mine. School ends in a couple of weeks so i think i will just scratch build it when i have the time. Hopefully it will work out.

[K0na_stinky]

As far as I know there will be 3 new rimfire motors. A tiny 250 size, a "50cc" and a "65cc". They were up on towerhobbies for a day or 2 but they took them off. And if you read the manual for the 84" Reactor it talks about the "50cc" size motor. If I remember right its a 75-80 mm motor, I can't remember the kv.

I'm scared about going as cheap as I am already on the batts. I only use Flight Power batts, I really trust them. I have been reading about the HYPERION batts and they seem to be good so I figured I would try them out.

I'm intrested in your build also, I want to see how it works out and how light you can make it.

I just went back to work so all my spare time is gone. :(

[parkfly27]

Well, time is money and money is time ;)

I'm hoping i can get mine super super light. That's why i'm going with the super-light 10S setup.

I know for a fact zippy flightmax batteries are very good. I compared a flightmax 2200mah 3S 25C to my buddys flightpower 2150 3S 25C in my funjet, and the plane went just as fast with the zippy as with the flightpower. Odly enogh, the zippy was cooler at the end of the 5-minute flight.

Even if the zippies aren't as good as big-brand lipos, i still don't have much choice since i can't afford any other brand. I am a bit skeptical about the big turnigy motors, as they seem to put out good power but don't last long. I guess i'll find out soon enough.

[K0na_stinky]

Well for now I'm just going to take one step down with the batts. I'll try the HYPERION's and see how they work.

I have been reading alot of bad things about Turnigy motors, some good things tho. Its hard to tell by people saying there "good". Some people say every one they know use Turnigy motors and they have no problems other then bearings in the big motors and if you over heat them the magnets are no good. Well what im wondering is how hot do these people think is normal. When my motors are worm I'm ok with that, if it gets over 100*F its to hot. All I have for motors are Great Planes Rimfire's. They have been running great, then run about 80*F all the time and have many many flights.

Once you get your motor let me know how it works.

PS. I'm a 18 year old kid that lives with his parents and I'm not goin to college, yet. So I can dump all my money into my hobbies, life is good.

[parkfly27]

lol, just wait till you start college. Things will change ;) I'm finishing my second semester of college, so once the semester is over, life will be good again. :rolleyes:

From my experience, and others i know, the smailler turnigys have been great. They are very efficent, and pretty robust. I have also heard about issues with the bigger ones such as bearing issues, magnets coming unglued, and shaft pulling up on the case causing the motor to sieze (could be very bad when hovering!!) :eek:

I'll just put the ESC on soft start, put some loctite on the grub screws, ect. as a precaution. I read that someone took the motor apart, re-glued the magnets, and assembled it with loctite on the grub screws and had no problems.

I'll be sure to let ya know how the setup (battery, motor) works. Also, if the fuse scratch-build works, i'll give you some rough plans in case you want to build a 1/3 scale from just the wings and tail.

[K0na_stinky]

You shouldn't encourage me, I spend way to much money as it is. :D

I've been flying for alittle over a year now. I've had 1 40" Goldberg yak(crashed it from flying in to small of a space), 2 great planes 40" yaks (one was crashed due to radio problems, other is still kickin) 1 47" EF yak (still kickin, even tho I hate it so much i try to crash 1/2 the time), a bunch of foamys... Great Planes flat outs suck, but the new pluma rocks. Had one of the Goldberg 67" Edges, one of the ones that the wings broke off of.... and the wing broke off (got a full refund too :) ). And my most favorite plane ever is my 60" Sebart Sukhoi, its a awesome plane.

Now I'm looking for a more awesome plane, and I think bigger flys better so I figure I should try a 30%. But once I get that I know I'll want bigger.

Having plans for a plane like your 35% would be awesome. Maybe next winter I'll make a 35% and lighten it as much as I can. Gas planes are way over built.

Oh yeah, up here in Canada theres still lots of snow on the ground. People call it "building season", but I like flying in the winter. Your plane is way more floaty because of the cold dense air.