Thanks Rob. I may be at the San Diego Mid-Winter thing. I'm also planning on a pattern meet in Phoenix the end of February.

I did a lot of searching about chargers. I had an Orbit Luxury V6.2 that I was using to charge the 5s4p I use in the Funtana. It would handle 6 cells at 5 amps. Orbit had a EPROM upgrade that would make it handle 11 cells at 6 amps, so I got the upgrade. I had been very happy with the Orbit, so I decided to buy another one, but this time a Pro model that will charge 11 cells at 8 amps. My plan is to charge the pack at the field all at the same time with one charger. You don't need to wait for the pack to fully charge, so charge time after a flight looks to be about 45 minutes. I'll then fully charge the packs at home, which with the way the Orbit slows the charge rate down as the voltage goes up, takes about 1.5 to 2 hours.

Still lots to learn about these electrons!

I've got a bank of orbits and just got a astro a couple of months ago..

the orbit is great, I charge most of my lipos on it... the astro is quicker and half the price.
I've heard you have to watch the astro regarding the auto detection of the cell count, but I have not experienced any challenges there..


Rob

Tony
Your plane looks awesome. I hope you make it to MWE.

I fly a lot of 10s set ups and Charlie Wang at TP doesn't really recommend charging 2 packs in series if you can avoid it. It can lead to more of an imbalance between packs. And that leads to cells failing.

I have Orbits, Schultze, and Astro chargers. I use the Astros at the field because they are a lot faster and very cheap. At $120 each, you can have more than one for the price of a single Oribt. As far as charging problems, Astro has a ROM upgrade which will lock in the initial cell count and not check and vary it later in the cycle. So that problem has been taken care of.

I like all the chargers but the Astro is the fastest.

-- Kyle

Hello Tony,
I'm pleased to read about your success with the Partner.
I was also tickled to see you on TV in program on UAVs in Defense and Research.
What were the particulars on that program?

As I read your and Jason's discussion about redundancy and radio battery eliminators, it struck me that a small (300mAH) 4-cell nicad pack and the BEC can be added together through a pair of high-current schottky diodes. I'll get a proper part number and attach a schematic in a post, soon. The same could be done with 2 BECs on each of the 5S4Ps, but that would require BECs with "floating" outputs. They are not available for E-flyers yet, but I think that such equipment is due, once you pioneers help define the problem. Do you think that a single BEC that runs off the entire 10S pack would be alright? That would be simpler, and it could be way over-designed for reliability. Are we concerned with LiPos failing open circuit?

Regards,
Dean Pappas

Hey Dean! Good to hear from you. You and your brother still taking rentals to the drag strip?

I've had some people tell me about the TV show. I haven't seen it so I don't know what it was referring to.

I have been told that occasionally a new pack may develop an open, so hence the desire for redundancy in this model. I have yet to experience it, but my experience is still limited. I have installed one of the UBEC's into my H9 Funtana that has a Hacker/Thunderpower set-up. Only flew it 2 flights so far but no problems.

I got 6 more flights on the partner today. The conditions were about perfect for trim evaluation, nice and calm. Jerry Budd came out with his Webra 1.60 powered modified EMC so I got to do some side by side comparisons. The electric is every bit as good. I would get just as high about as quickly. And the downline braking is better. And of course, the servos like the no vibration! I think you'd really like this system.

Hey Tony,
No, I haven't taken a rental vehicle to the Drag Strip in some time now!

I thought a little more about the UBEC reliabilty issue ... is the only concern that a cell (actually 3 or 4 in parallel) could go "open"?
The much lighter solution (compared to a backup battery) is a Schottky diode across each series cell. The cathode goes to the positive terminal so the diodes do not normally conduct. If a cell dies, open, then you loose 3.7V + 0.4V for the diode. You should notice the power drop and land, but landing is still an option. The diodes need to carry the motor current, in case of a failure, so they are sized for 65 Amps. That's really not a big part (or two in parallel). By the way, what is a Ubec? I know what a BEC is, but what's the U stand for? Who makes the item you're using?

Actually I am positively excited about the prospect of electrics. The whole right-thrust discussion a few mails ago was telling. To begin with, I agree with you, and at worst, you adjust the right-thrust until you find yourself pushing left rudder in the outsides, as often and as far as right rudder in the insides. It's airspeed sensitive, not throttle position. The plane without this compromise will not have a big ugly chin to house a four-stroke: it will look like a big Banshee, or Shoestring. I have already been drawing, aimed at the 2005 season. Do you have weights for the major components? Since you were so close to the weight target, out-of-the-box, your finished wing,fuse, and stab weights would be interesting.

I'll try to find out which TV program it was ... you need a copy, compadre!
Regards,
Dean

Well, here's an update.

First to Dean. The U stands for Ultimate, just the manufacturer's name for it. Your diode discussion sounds good, but I may have had the ultimate reason not to go the BEC route. I was flying yesterday with some new packs, and I forgot to put on the velcro self adhesive strips that keep the battery from moving fore and aft. Got away with it for one flight, but on the last flight, I did a hard outside 1/2 loop after a manuever and ejected the entire motor battery pack from the plane. It knocked off the canopy enroute. The plane was upright and fairly high, going downwind, still flying well, so I kind of took my eye off it to follow the canopy down. I thought at first that just the canopy had come off. It wasn't until I turned base to land that I realized I had no power. The model was still controllable right to the landing, which sort of pancaked in a bit. I found the canopy fairly quickly, and there was minimal damage, but it took till the next day to find the cells. They're a bit mushed and I'm hoping that they can be repaired. Anyway, I found a way to get the "Ultimate" open in the motor batteries.

But on a high note. I just finished the first day of a pattern contest here in Lancaster. I have to say the more I fly this thing the more impressed I get. Today was awful, 20 to 30 mph winds, cold as heck. This model handled it with ease. The knock on the electric from the World Champs was that it had problems in wind. Not this model. Best I've ever had. I'm more fired up about pattern now then I've been in years.

Oh, BTW, another somewhat telling bit of info. Gauging the R/C battery voltage drop from flight to flight, I estimate the consumption is about 1/2. Without the vibration those digital servos are working a whole lot less. And I am beginning to believe that is translating into better control of the model. All positives.

This has really been a lot of fun!

Tony
Great meeting you and watching you fly the Partner. It is very impressive and every bit as powerful as Jason Shulman's plane. Also, thanks for all your help at my first Pattern event. Special thanks to Jerry for encouraging to fly. It's pretty neat to see 3 good performing electrics at one pattern meet.

Here are some photos --

== Kyle

Here's Tony's Partner in the foreground and my Efactor in the background. My plane looks like a tooth pick.

-- Kyle

How about some results?

Tony: Now that you've had a change to fly the Partner for a bit, would you still soft mount the Hacker? I'm using a C50 12XL in a 90 size aerobatic model and there's virtually no vibration in the airframe and the model is as quiet as can be in the air.

Mike M

Hi Tony. First off, great to see you back in pattern and fired up about it. You may not remember me as I am a novice flyer compared to you, but I am Jevan's brother. I wanted to know where do you come up with the information for all of the electrics? I would love to go electric and don't really know where to start with a 2m ship. Actually, I just bought a ys140L from Vic down in your area and I think it used to be yours!!! Boy I hope I never have to run it and can change to the electric at least for pattern. Anyway, hope the wind dies down for ya. Beautiful plane!!! Will be seeing you at the contests this year hopefully. Take care, good luck. Krishlan

Tony - How did day two go ?

Any results to share with us ?

Hi Tony,
THanks for taking the time to write up your experiences with electric pattern. I think you may get a new revolution started ( I know I'm VERY interested). Glad to hear your Partner escaped your battery ejection mishap mostly unscathed. Many years ago a friend of mine built an MK Curare, but modified the canopy area into a hatch. Unfortunately, his hatch latch mechanism failed and it popped off; releasing his Rx battery into the wild blue yonder as well. You know the result.
Happy Flying,
Will B.

Hey Tony, glad you got the ship back!

Imagine if the pack had wedged itself in the tail? Hoowee!
So I take it the pack with the BEC was still in the ship.
I had wondered about the "G" loads on 54 ounces of battery ... so real battery boxes are in order, eh?
I was actually wondering about the effect of putting that percentage of the plane's weight far from the vertical CG: I have an old Prettner Supra-Star that I'm contemplating electrifying, and the batteries would be outside where the external pipe would hang.
So the Partner suits you? How's the spin/snap?
My guess is that a single LiPo cell and a properly done switching "boost" regulator will be the lightest devoted flight-pack battery system.
No one does this now, but a switching supply will work nicely, provided that the receiver (at least) is fed by a linear regulator that isolates it from the switching noise.
Too many ideas for projects!
write me some time <[email protected]>
Dino

Kyle,

Thanks for the kind comments. It was great meeting you and getting to talk "electric". The weather was much better on Sunday and we got in 3 more rounds. Here are some of the results that I can remember,

F3A - 1st -Troy Newman, 2nd - Greg Frohreich, 3rd - Jim Woodward
Masters - 1st - Tony Frackowiak, 2nd - Jerry Budd, 3rd - Rusty Fried
Sorry, I can't remember Advanced and Intermediate.
Sportsman - 1st - Terry Hemmis (our local lady pilot!), 2nd - Kyle Mashima(I'll bring your plaque to MWE!)

Troy was having engine problems with his Smaragd and needed a complete score for the last flight, so he flew the Partner. He got one quick flight on it practicing Friday, so it was still pretty new to him when he flew it that last round. He put in a great flight and proved the effectiveness of the model in the F3A pattern. Maybe he will add some comments here later.

Mike M.

I'm not sure I would change anything in this model, it seems to be working very well. We did a sound measurement on it Friday using Troy's meter, and it measured 89 db, well within the limit. It may be an interesting experiment to hard mount the motor and see if anything changes, but certainly a little vibration isolation isn't hurting anything.

Krishlan,

Glad to hear from you. If you want to get together to fly just come on up sometime.

Will B.,

I did the R/C battery ejection years ago with an 1/2A Ace Pacer. Just turned off the TX and watched it hit. Oh well! I am absolutely convinced electric will take over pattern, there are just too many advantages.

Dean,

I wasn't using the UBEC in the Partner yet, luckily, as I ejected both 5s4p's in my little stunt. That's removing 3.1 lb all forward of the CG and the thing was still controllable. Since the new TP cells about to come out will pull another 10 ounces off the battery system, I don't think I'm going to bother to use the UBEC. Frankly, I want this model just a touch under the limit. I really think we can get these things too light.

BTW, the UBEC is a switching regulator. I have installed one in my H9 Funtana, no problems so far. But I think I'm going to stay with a separate R/C battery, at least for now.

The stall/snap characteristics are excellent. In the spin, I enter with high rate elevator, and I have to reduce that elevator after the entry, or it will go into a sort of weird flat spin. With the reduced elevator after entry it is a very stable, slow spin that stops instantly. The snaps couldn't be better. There's a vertical climbing inside snap in the P-05 F3A pattern, and when I've played with them, they are great. When Troy flew it on the last round, he absolutely nailed it.

Concerning the vertical placement of the batteries. That is the only real trimming, other then control gains, that I've done. With the original mounting of the motor batteries, as in the posted pics, the model had a slight pull to the canopy in the vertical lines. I lowered the batteries 1", and instead of stacking them side by side vertically, I laid them down horizontally. This lowered the vertical CG and now the uplines are perfect. I think if you mount them very low with that Supra-Star you may have a pull to the LG.

Now to get an Excellence framed up for Jerry so I can start on my next one!

Well in a word the Electric models in F3A are awesome. I had not actually seen the setup that Jason flew until last Friday. I was impressed. Number one the weather was good and the model performed really well. In looking at the performance you have to realize the way things are working.....The model never goes into the Afterburner mode that the glow motors with a 140 or 160 motor fly with.

So the Speed of the model is really controlled by the 22" prop. This means the model is flying slower but its more like a tractor. It has vertical as good as any of the top glow setups. So I don't think power is an issue in the comparison. They both are about the same.

The Speed range on the glow model is larger. You can fly faster and almost as slow as the Electric. SO this is where I see an advantage to glow or is it?.... I'm undecided... The other thing I do see is that the electric is easier to make constant speed...because its window is less the pilot can be all over the throttle and not make huge changes in the speed category. Don't get me wrong I feel the speed of the Electric model is not too slow....it is just very different both in watching it fly and flying the pattern with it. Greg an I had discussed the results of the model in the wind as a questionable thing...Well Saturday didn't disappoint us...it was 20mph easy almost all day. The model seemed to fly well and not different than the glow models. I think at times I wanted more speed...but this could be props, or changes in setup....Then again it didn't need the speed it had plenty of power for everything. P-05 and Although I didn't F-05 with it....for sure the model can do it on the Hacker power plant.

I have no doubt the electric models can perform equally precise sequences and also compete on an equal footing with glow models. The Electric model has a different presentation that looks different from the glow models. I have not decided if it is better...but it is different. I can say this......It will cause your mouth to drop open when you see it perform the sequence. For sure its not any worse off....maybe not better...for sure not worse.

Its very much like a Ballet type of thing to use a phrase from another contest pilot this past weekend.

Things to get used to:

The sound. We become very dependent on the sounds of our models. We listen for the motor to speed up on a top box horizontal line.....this is a slight clue its descending. Also the stall turns are different...the slow throttle back to the pivot point....the sound of the motor helps this out or at least for me. When the model first starts up and takes off...the motor sounds like a park flyer....and you are not impressed. Once you enter the box and start to perform the sequence the noise blends into the pattern and it acts to clue you on the speed of the model.....Just like the glow models. The problem is the cue from the electric is different in the ear.

I can see where the speed and sound of the model can really be an asset to a pilot that is well prepared. It is elegant and sophisticated. A glow motor is more throaty and powerful. At for glance the electric is not the most ballsy setup...but once you watch it pull a vertical line snap and continue to pull the line without speed decrease or hesitation you gasp.

Next is the model's locked on feel. I have spent lots of time with the Smaragd. Since the Partner is basically an extension of the Smaragd and some improvements.....I was able to step right into a model that I know flies very much like my model. So this was an advantage.

Overall the only downside of the Electric deal I see....and this is after a 6hr drive to think about it......

The technology is new. Where will batteries take us? Where will the motors? Gear boxes and prop experiments? And How long will the batteries last?

The only disadvantage I see to the system is its cost today. Now the words we all use is that the prices will come down...and they might very well drop a bit. But just like a PC the price may stay the same and the performance increases giving you more bang for the same buck.

Who knows....but I'm sure Hacker and Thunderpower are indeed planning strategy to both be profitable and serve modelers interests. I think its only a matter of time before Electrics migrate into all aspects of modeling.

Will they overtake glow in 5 years? I don't know....Will they replace glow? I don't think so. But I do think they will attract a very loyal following and rightly so.

Its a very good thing for modeling. I think its a very good thing for F3A....

Troy Newman
Team JR

Tony,

Have you done any current/voltage measurements to get an idea of what your input power is? I am curious to know whether you are getting close to a wet model's 230-260 watts/lb power to weight ratio or is the big prop just so much more efficient than the typical glow sizes?

Regards

Malcolm Harris

I have yet to actually measure my model, but the same set-up in the Rhapsody produces 2,300 to 2,400 watts. At 11 pounds that's 209 to 218 watts/pound. Slightly less, but the 22-12 prop turning at 5,800 is much more efficient.

I think Troy's comments are pretty much right on. For absolute pure pattern performance, it is really a toss up right now. But for ease of operation, low vibration hence low maintenance, and some possible advantages in speed control in the pattern, the nod goes to the electric.

Tony,

Sounds like you're having fun and the plane looks great. I can't wait to see it at either MWE or Phx. I received my Rev-Pro, but have to finish an Angels Shadow for a friend first. I may let Sean work on the Pro so I can have an electric at Phx. I liked the install of your plane. If you have any close-ups you could shoot over here, I'd like to "borrow" some of those ideas for the Pro. I'm particularly interested in the battery and gear mounts.

I too forgot the "safety straps" around the battery pack once during practice at the Worlds before the finals. Thankfully they did not depart from the plane, or even the mount (small pieces of Velcro under the pack held it).

Hi All,
I've seen Tony's electric fly about 10 times now and also judged 2 of the rounds this weekend. I'm starting to view this as tool that could help you score better. I view most my purchases that way asking this, "will it help me score/fly better?" From the judges perspective, the electric is very pleasent. You absolutely don't need the audio "drama" of the powering on of the glow (2 or 4 cycle), and the abscence of the smoke trail definately helps by not showing every little deviance of either the plane or separate wind turbulation. Without the rush of glow audio noise, the plane never really gives the "impression" of being rushed, in trouble, or loud, to the judge. We'll see what happens in the long run...

From the pilots perspective, eliminating 97% of any engine performance variance from day-to-day, location-to-location, fuel-to-fuel, plug-to-plug changes (or weather) could do nothing but help you score better. A tool that would allow you to hold engine/motor performance relatively constant throughout the whole season could be priceless to the hard-core competitor.

Planes: For a national/world competitive model you need to start with a dedicated electric platform which may disuade some. For the local contests, maybe you could convert a glow model if it is already light to begin with. However, if you have a 10.5 lb glow model with 20 oz of fuel, an 11 lb electric model is actual lighter for probable time you are flying the sequence????

I'm more than impressed with the concept and now reality of it. The more I think about it, the more I think that by removing the glow style engine day-to-day variances, the higher your scores are going to go. Good job Tony, & Jason.
Jim W.

The way things are going as far as making weight with current "glow" pattern planes seems to be similar between the already converted. Other than Kyle's E-Factor electric pattern plane, the "glow" planes that end up at 10lbs RTF as glow set-ups seem able to be converted to electric and make weight. But in order to make weight one would run a 10S3P pack though. In the next couple of months you can run a 10S3P with the characteristics of the current 10S4P packs without trying to be careful about loading the packs hard. This will make most any plane able to be converted to electric. Tony's plane being only 6 ounces over 11lbs. is the same that the Rhapsody's were over with the 10S4P packs.
I am going to try to keep track of the weights of the Rev-Pro as I go...if I get a scale first to do so. We had done this with the Rhaps, but we lost the paperwork.

Tony,
I was thinking that I might have a vertical CG issue.
Later,
Dean

Jason thanks for putting this technology where we're heading, iwas a little spectical before the Worlds, but in reading this it seems that the electric fits the way I like to fly to a tea, granted I'm not at your level and will never get there(well at age 55).
Tony thanks for following this up by putting on rcu wish you had some of the info on the NSRCA discussion list also would get alot more people involved, but the RCU is great for the pics.
Ok now for a dumb question as I remember right in Poland Jasons plane got like 30 minute flights, and yes I did read Jasons last post, so if we only fly at 8 to 10 minute contest flight what would be the minimal Batt's for that time frame, and charging time for them.

Thank both of you and keep it up.
Steve Maxwell

Steve,

In one Master's routine, when I recharge it puts in an average of 4,000 mah into each of the two 5s4p's. At an 8 amp charge rate, that's about 30 minutes. In reality, about 20 minutes and the packs could fly another contest flight.

When practicing I usually fly 2 complete Masters patterns, about a 13 minute flight. In 40 minutes I the pack would be charged enough to do that again.

Hope that helps!