kyleservicetech

I am presently picking up parts for a Hanger 9 Funtana 125 for next year. Currently on hand are 24 A123 cells to be configured as a 12S2P pack, and a Hacker A60-16M motor. The prop will likely be a APC-E 19X12, the ESC will be one of the high voltage Castle Creations units. Using the A123's will result in a model running 150 Watts per pound, with motocalc suggesting it will climb out straight up at 3000 feet per minute. Measured performance, 68 Amps and 6700 RPM on the 19X12 prop for a measured 2300 watts.

These models are usually powered by a gasoline or glow engine, and the thought came up to compare the total weight, wattage input, prop thrust and pitch MPH of the Hacker against several of the larger Gasoline or Glow engines.

This has been placed into a chart in PDF format, attached.

It's interesting that the Hacker, when powered by a 10S1P 4300 Milliampere Hour Lipo will match, or even exceed the power of a 30 cc gasoline engine, and at the same time, be within a half pound or so of total model weight.

The off setting part of this, is the Hacker will be limited to flights on the order of 5 or 6 minutes where the gas or glow engine powered unit can fly for double that on a typical tank of fuel.

The various glow/gas engine prop RPM values were taken from published tests from the various magazines such as Fly RC. The watts, pitch speed, and thrust were derived by making up a phony electric motor in www.motocalc.com and tweaking the motors parameters to match the published engine results in the magazines.

Perhaps the watt flyer readers may find this information useful
(Note the chart lists an 18 inch prop for the Hacker. This prop is a little to small for that motor. I've been flying with an APC-E 19X12 wide blade Electric prop. That setup pulls about 75 Amps, and 2600 Watts and 6900 RPM, something the Hacker A60-16M motor is very comfortable with.)

kenchiroalpha

Hi Dennis
Outstanding
Great information
Thanks ever so much
Take care
Hank

CHELLIE

That sounds like you have a neet project going on, Good luck with it, thats the only small draw back to e power right now is somewhat limited flying time vers gas/glow but, i normally fly for 6 to 7 mins on one battery charge, and thats good enough for me, infact, most people flying glow only fly for about 7 to 8 mins at a time, so good enough Take care, Chellie

kyleservicetech

Hi Chellie
Heh Heh

Last Sunday, one of my club members was flying a 150 cc twin cylinder powered model with over 100 inch wing span. And in between flying the big gasser, he was flying a little 300 watt acrobatic electric model. That thing was over 200 watts per pound. Wound up with three flights on each of them.

He was flying BOTH models about 8 or 9 minutes per flight!

Larry3215

Well, its a little more than just the flight time difference.

The electric system may be able to match the glow/gas power to weight if its a hi quality setup like this one - but dont forget that the glow/gas guys can fly at full power for the entire flight if they need/want to and we cant - not if we are trying to compete with them on a power to weight basis.

I had a 3200 watt Neu motors setup in a KMP 87" Yak. Mine weighed exactly the same as the gas guys flying 50cc engines. My model was just slightly better at pulling out of a hover but they could fly much faster average and much faster top speed for a LOOOOOOOT longer than I could.

By the way, Im running a Hacker A60-20M in a scale project Im working on that weighs 26 pounds. Im running it on 10S spinning a 21x12 3 blade carbon prop. Peak power is 2660 watts. Great motors!

kyleservicetech

Yep, some of the advantages gas has over electric. Plus, the electrics are pretty much a fixed RPM power source, where the gas engines will "wind up" if unloaded, so straight and level, they are capable of flying faster.

On the other hand, look at one of those 50 cc gassers when they are running, the elevator, rudder, ailerons, everything is vibrating! We don't have that problem.

Octavius

This is good info. IMO I don't find the limitations things that would come into play very often.

Except for a few rare cases nobody flies their gas/glow planes at wide-open throttle for the whole flight anyway. OK, the guys with crappy, old engines do but that isn't normal.

For myself my current go-to glow plane can fly for 20+ minutes but I like to take a break before 10 minutes.

Larry3215

Yeah, other than the huge difference in energy density, I think electrics win over gas/glow in most every other category, or at least come very close. I have no plans to go back

kyleservicetech

Something else here:
After about 1000 flights on my 2003 150% Electrostreak, I put two small holes in the top of the wing. Could not figure out why, it was weird.

So, during putting a MonoKote patch on it, I found the 7 year old MonoKote on the top of the wing had the tear resistance of a cheap piece of cellophane. In fact, most cereal box cellophane liners had far more strength. The MonoKote on the bottom of the wing was better, but still not as good as a brand new piece of MonoKote.

Absolutely zero resistance to tearing. Along with that, most of the adhesive between the MonoKote and the balsa wing structure had let go. It was easy to pull off the entire MonoKote wing material! Guess the sunlight burning down on that wing over the past 7 years had a real negative effect on the MonoKote.

So, now for the good part. After getting off all the old MonoKote, I had a clean, bare balsa wing structure. Zero glow fuel, zero oil, just a bare clean balsa structure that was easy to re-cover!

Having had other results with glow fueled models in old models decades ago, that, was very nice.

kyleservicetech

I picked up a brand new, out of the box Carl Goldberg Electra 330 78 inch wingspan model from the local hobby shop for $75 less than the hobby shop paid for it.

The manual for that model indicates that throttle management is Mandatory! The model can overspeed in a dive, causing structural failure. Most of my club members that fly giant scale models do not fly at full throttle all of the time for the same reason.

albsurfer

I realize this thread is almost a year old, but...
I have a GW 57" MX2 using a hacker A40-14S, ICE 75A Heatsink Ver, and an APC 14x7E. It's not the fastest, nor the most aerobatic compared to a nitro version, but I can get 9 min of mixed flight out of it with a 5S 5000mah lipo pack. I'm switching to an APC E 14x8.5 and should be able to still get 8 min of freestyle flying out of it. I was thinking of converting a .91-1.20 size Phoenix EDGE 540 to E Power, but I don't think performance + time would be as good as a large Nitro or Gas engine.

Till working on it though!

kyleservicetech

Nice thing about all these electrics, no vibration shaking your radio and servos, and no glow fuel getting everywhere. Just yesterday, a club member lost a big gasser when everything went dead. The model went straight in at full power. Could not even save the receiver. Don't know the cause, but you always worry about vibration getting into something critical and shaking it loose. Many years ago, one of the model magazines ran studies on vibration levels in glow powered models. The magazine found vibration levels on the order of 30 g's at the servo location. NASA gets worried at anything over 10 g's or so. Now we've got the big gas engines, that to me at least, suggests even more vibration.

Right now, I'm working on a Great Planes Giant Big Stick conversion to electric power.

Power setup is a Hacker A60-16M motor, 19X12 APC-E prop, 12S2P A123 battery pack, Castle Creations 80 Amp ICE ESC, CC 10 Amp uBEC. The model is 80.5 inch wingspan, 1518 square inches, weight measured exactly 15 pounds. This model will be running about 180 watts per pound.

I was getting 6 minute flights using about 60% of the battery on a previous very overweight 19 pound model. Previous measurements downloaded from the ICE ESC shows that motor puts out 2700 Watts under the above setup, with a peak just over 3000 watts. That 19 pound model would climb out at 45 degrees and keep on going. It just was not fun to fly though, landings were a real . Go to slow, and the danged thing would drop a wing, and fall like a brick. That bent the 1/4 inch thick landing gear so many times I was getting tired of it.

So that 19 pound model is being retired. The same Hacker power system is going into the Big Stick. But, this is Wisconsin, we had our first snow this morning, so it probably won't fly until April next year.

One thing about these larger electric conversions. You can get away with a cheaper motor on the smaller models say under 500 watts or even 1KW or so. But, IMHO, running these giant scale models leads into weight and power issues. Some of the cheaper larger motors might be running 70 % efficiency per www.motocalc.com. My two Hacker A60 series motors (A60-5S and A60-16M) are running at 90% efficiency per motocalc. That is a notable difference. These motors are not cheap, but they do work and work well. Plus you can run them at their rated watts and amps and not have overheating issues. (I've got 8 of them.)

Next few weeks, I'll create a thread on this Big Stick and show how it went together.

Henry Sistrunk

Here is mine. Rimfire 160.
Henry

kyleservicetech

Hey, that looks good!

What's the battery, prop, watts, amps and model weight? And, how does it fly?

Henry Sistrunk

I don't remember. Will check tomorrow. Flies great on 10 cells. The motor in the photo died fairly soon and was replaced by a Rimfire 160.
Henry

kyleservicetech

Kind of irritating, Rimfire is among those motor suppliers that don't provide motor winding resistance. That value is critical for determining motor efficiency and so on. Winding resistance is easily calculated by using two digital volt meters, a power resistor, and a battery. (Or invest in a multi-thousand dollar micro-ohmmeter. I did use these $$$$ meters at work before retiring.)

As indicated I've got 8 Hackers from A30, two A40's, three A50's, two A60's. Except for bending up the A40-10L motor in a crash where the wing aileron came completely out of the foam wing, those Hackers have been flawless. That A40-10L is now flying in another model.

Henry Sistrunk

The one that failed is a G Force 160. I have had good service from Remfire, Monster Power, and motors from Heads Up RC, also smaller G Force motors.
Henry

Henry Sistrunk

Dennis, A bit off the subject, but check Henrys Airfield at this site.
Henry
http://www.checkthesock.com/

kyleservicetech

Hi Henry
Interesting site, thanks for the tip.

albsurfer

Kyle & Henry, you guys have amazing setups!
In addition to my MX2, I have a couple of smaller foamies, one is a Hacker Super Zoom XL, and a 3DHS 47" Extra 300SHP. I love them all. But.. I really like the advantages that electric power can give you and that it doesn't shake the airframe apart.
My kit Swanyshouse profile PRIMO 40 3D plane gets shaken bad by my TT F-75S. A lot of guys are going E Power on these planes now, even in the 60-90 range.

So I still may get the 90-120 Edge 540 and do it electric. I've seen guys at my field lose plenty of gassers, even with good engines. A few weeks ago a Pilot RC 30cc SBACH 342 went into the ground when the 30CC DLE stuttered in a sharp bank low to the ground. Totalled the plane. Keep up the great work guys. I'm right behind you, but I don't think I'll do a 160 size stick!

albsurfer

Oh, one more comment. It's really hard to beat Hacker & Scorpion.
Hacker specs are listed low. The A40-14S only shows 50A max, but plenty of guys have pushed them to 70A without any problems.
Scorpions are a little heavy, but VERY powerful, durable and reliable.

FLY ON

Henry Sistrunk

OK here is some info. Weight with batteries is 13 lbs 8 oz, 18x8E APC prop,80 amp Hobbywing ESC, 1 4cell and 1 6 cell 5000mah batteries, 1 2000mah 6 volt rec & servo battery. Will put the meter on it later today and provide readings.
Henry

albsurfer

Forgot the A40-14S specs:

from Aero-Model.com
Technical information
Kv: 530kv
Diameter: 41.7mm
Lenght: 42mm
Weight: 208gr
Shaft: 5mm
Power: 900w
Li-po: 4s - 5s
Max current: 70A

Fm a couple of other sites:
· Operating Current: 40A
· Peak Current: 50A
Propeller: 14x10 - 13x6.5

The setup I'm using is the same as a 3DHS 59" SLICK.
I was using a 14x7 APC-E and getting 9 full minutes of mixed flight, including 5 hovers at altitude. I am switching to a 14x8.5 APC-E and will also try a 15x8 EMP. The EMP should give me great flying, although probably only 7 minutes. I should get 8 mins mixed on the 14x8.5. I am filling 54% of the pack on re-charge of my 5s 5000mah Blue Lipo.

kyleservicetech

Yeah
I've got a Hacker A40-12S motor, a very powerful motor for a 540 Edge T model, running four A123 cells.

kyleservicetech

Only problem I've run into on these larger electric models, is how to provide the DC power for the field chargers. I've not been able to make a 120 Ampere Hour deep cycle battery last more than a year or so. You can only get three or four flights out of one before it goes flat. (The 120 Ampere Hour rating is based on a 20 hour discharge test, and my Cellpro Powerlab 8 can run that deep cycle battery flat in three hours. Looks like that high discharge rate cuts its ampere hour rating down by a lot, perhaps even by 50%.)

This has been in use for the last half of 2011, so far, it has worked out very well.
http://www.wattflyer.com/forums/showthread.php?t=63918