I can't seem to find any information on Jason Shulman's Electric F3A,


Does anybody have any info, how about it Jason???

Here are the results of a quick "Google" search.
http://www.google.com/search?q=Jason...UTF-8&oe=UTF-8

There's been some talk here on RCU, too, over the past few weeks.
http://www.rcuniverse.com/showthread...t=f3a+electric

and

http://www.rcuniverse.com/showthread...t=f3a+electric]

He was flying a Rhapsody from lorenz (www.f3alorenz.de). "normal" 2 meter patern plane, but they were laid up a bit lighter (no vibration to worry about, so can use less material in some places). Power system is a hacker C50 acro, 14 wind if memory serves,.. geared 6.7 spinning a 22X12 APC electric prop using a hacker 77-3p controller and 10 series, 3 parallel lithium polymer batteries from thunder power, total capacity 6150mah. not sure on specific servos , but futaba radio equipment of course. all up weight 10.6 lbs.

Thanks guys, most fascinating..

Garry,

I saw a rumor over at the Ezone that Jason went through a lot of batteries and motors. I know you know the people over at Hacker pretty well. Are any of the rumors true? If so, is there any explaination as to why?

I'm awfully close to parting with a bunch of money for a big Hacker C50 power system and some Lipos , but I don't want to be part of a beta test at that price.

Thanks,

Wiz

Those posts on ezone are news to me also. I talk with the hacker importer daily (Sean Plummer owns aero-model and hackerbrushless usa,.. you'll see his name in Tony's reports, he went to poland with them). I do know they changed motors at one point, not due to failure, but because they wanted to be overly cautions since it was the world championships. Although we've ran some of these motors (the one in my 2meter Funtana for instance) for many hundreds of flights at these power levels, we're not sure when or if there will be a failure. The battery thing is news to me. I knew they were flying 4P packs(8200mah), then switched to 3P (6150mah)since that was plenty of capacity, and they wanted to get the weight down, but I didn't hear of any failures.Static current ended up at 72~73 amps at full throttle which would have pushed those cells to 12C and Charlie rates them at 5C, so it's not like they weren't pushing something past specs (over double actually ). personally, I've pushed 4P packs to that and have not had any failures, but I've "only" been flying those cells for about one year now (I think october is when I got the first ones, which are still going fine by the way). I have 100% faith in the motors/ESC and the current revision of gearboxes (beta time, as you mention was last october through early spring, and gearboxes were redesigned a couple of times). I don't know how much actual flight time in testing gives a good comfort zone, but i've been involved with the C50's since last october (had one of the first ones in the funtana at the TOC) and in this final version, I think the 2200~2500 watts of power we're putting through them now is not at the limit of the motor.

Hi everyone,

I just wanted to ask if someone knew why Mr Shulman did not use an outside rotating 3phase-motor in his plane, which meant he could save the weight of the gearbox. I hear these types of motors are quite powerful even for pattern planes.

I bought myself one of a smaller size from http://www.flyware.de/ and look forward to installing it into a Tai Ji 40 or a similar plane very soon.

Although prices for batteries are still high, I aim at replacing all my combustion engines with electric motors one day and fly competitions with it.

Regards,
-Fabrizio

Thanks for the answers Gary. Hopfully, you or sombody else in the know can give the straight scoop on the dependability aspect of Jason's F3A ship at the WC.

I think the answer is an easy one. Jason is a Hacker sponsored pilot and Hacker dosen't make outrunner motors. Besides that, the school is still out on the efficency of theese larger heavier motor types.

BTW, I have a outrunner myself. It's an AXI 4120/14. It's very quiet and seems to work well in it's current application (Magic 3D) but it is quite heavy.

Wiz

Had a brief conversation this morning and was told that NONE of the equipment he used was damaged or broken. They thought there was an issue with a couple batteries but it turned out it was a temperature thing. Apparently it got a bit cooler in poland, and the lipoly packs like to be 100 or so degrees. The cool packs would be a bit weak on power the first minute or so till they warmed up. All of the packs he took are still in use without any failures. Also the motor change was precautionary, no specific reason except that the motors in the planes had been used quite a bit in testing beforehand, and they had spare new setups with them. In my C50's I have noticed that the gearboxes get a bit more noisy after a couple hundred flights and need to be greased. Removing the gearbox isn't a simple thing to do at the field, so if I had a spare motors I'd probably do that also in a contest at that level.
As for an outrunner,.. I've seen some pretty good numbers published, and I've ran some of them. they work very well. I haven't, however, seen one that will work at the 2.3 kilowatt level (I know there's one that's being advertised to run at that level, but I haven't any personal experience with it). The actro's and lrk's seem to work very well, but never to the specs I've read, always below the geared inside runners. Also a weight penalty since a big direct drive outside runner that can be run at the same power level is almost always a lot heavier. One large direct drive motor I know of works really well,.. almost equivalent to the C50 hacker, but at 3 lbs instead of 1 lb

That's interesting that the Lipos like to be run at 100 degrees. While I've heard that Nimh cells like to be warm before use I've never heard anything about Lipos needing to be warm. In fact, most people say thay charge at home and then go fly the next day.

Just the same, I'm glad to hear that there were no actual reliability issues for Jason at the WC. It makes it a lot easier for me to buy those products. Especially, because I know that I won't use them as hard as Jason does.

Wiz

For all those who may be interested in reading what Jason had to say about the reliability of his electric power system and what his setup was follow this link.

http://www.rcgroups.com/forums/showt...5&pagenumber=3

Wiz

I see, although I do not like the noise gearboxes emit. With the kind of power Mr Shuman had on his plane, he could probably also have used an outrunner, the additional weight would not be much of an issue. He admittedly peaked in at 92-93 dB during his measurements, which is quite close to the 94 dB-limit in F3A competitions.

Anyway, we will see more electric pattern planes at our fields and at competition in the future, I hope that prices will soon go down.

Regards,
-Fabrizio

the nois on his electric was that high? wow thats somthing i didnt know.

From what I gather, the prop is what's making the majority of the noise. I've also heard that the plane was very quiet in the air.......just not so quiet on the ground.

Wiz

regarding the noise thing,.. they're generally quiet (can't even hear them) in the air, but the noise check I'm told is over hardtop, and the 22X12 prop is a lot closer to the ground than the usual 17~18 inch props. I was told there was a 1db difference just from raising the tailwheel so the plane was in level flight mode just sitting on the mains, versus having the tailwheel on the ground (prop tips closer to the hardtop). anytime you get a prop close to something it gets loud,..as evidenced by all the little foamie zagis with the prop very close to the trailing edge. I have a hard time flying my larger electrics when there are .46 powered glow planes in the air, as I can't hear anything. It's really amazing how much you rely on the sound for throttle control

In British Artistic Aerobatics Championships last weekend third place pilot was given noise penalty.He run Hacker C50 6.7:1 gear and 20-22 diameter propeller. RPM was only 5000s. What is strange some Glow pilots were awarded noise bonus.

Esa

I find the whole noise measurement thing to be kind of contradictory, honestly. At least, in that it's measured on the deck, and not in the air. If the purpose is to ensure a measure of quiet regarding "offensive" noise levels to those on the ground on and near the field, then an airborne measurement makes a whole lot more sense than one on the ground, since it isn't usually a plane on the ground that the general public complains about as being noisy.
The electric planes as a whole are much quieter in flight, where the "offensive" noise is generated by IC aircraft, and deserve a bonus, not a penalty.

Rick