patrnflyr

My Feedback: (7)

Ok, I've been following the threads for a couple of years now. I've been flying the small electrics for about a year now and have been in pattern for about 7-8years but only fly a couple of contests a year in the intermediate class. I think I'm ready to take on the commitment of an electric pattern ship. I presently have a new Angel's Shadow with a YS DZ 140 and JR 10X. (I do know how to outfit the radio stuff and make it fly right!). I recently bought the new TP charger 1010C and balancer with a AC/DC converter also. I really do like the outrunner motors and am seriously thinking about the AXI f3A motor. Any recommendations on where to go from here? Just lately, I've noticed a mAh usage drop from the previous 8000 packs to the much smaller 3700/5400 packs. This has me a little bit confused but I'm sure somebody can help me out. I'd really like to get the very best plane setup possible that won't go "extinct" in 3 months. I have a few planes on my idea list like the Angel Shadow Electric, Pinnacle and Genesis ARF. I'm not a good builder, but an excellent assembler. Finally, I really like the Thunder Power setup as I have the chargers and balancers already available so going that route would be preferable if at all possible. Thanks again in advance for your help!

ExFokkerFlyer

My Feedback: (4)

Well all of your choices would work, just goes to personal preference right now. I have a Genesis ARF with an AXI 5330/F3A and it flies great. I have seen the E-Angel's shadow fly as well and it's a beautiful airplane! Although... all the Shadows are. You won't go wrong with any of those planes listed.

As far as the batteries go. There are a couple of things at play here actually. When e-pattern started it was necessary to use the 8000 mah packs as the C ratings were relatively low. The battery technology wasn't where it is today, and with the higher capacity you were able to draw the 60-65 amps the motors were pulling. Also, there wasn't much experience as to how much was really needed, so bigger is always better right?

With the batteries we have today, the Flight Power Evos, PolyQuests, and Thunder Powers (didn't mention Kokam because they really don't have a pack that's the right capacity or weight yet, but it's coming I hear) the battery ratings are 12-20C for max cont. and much higher burst ratings... so that packs can be smaller in capacity. But how small? It all depends on your application.

Right now flying the Masters sequence in 7.5-8 minutes I am seeing a usage of 2000-2400 with my Thunder Powers and 1800-2200 with my Flight Power set. I have one friend who is flying a Hacker with a set of TP 5300s and is completing the FAI P-07 at around 2000-2400 pretty regulary. This is a considerable drop in what we flew last year, and were expecting for this year. There are many theories circulating in our circles about this... but it's likely a combination of throttle management and how the throttle curve is set up.

Battery technology continues to evolve and my sets of TP ProLite 5S3P 6000s were the best avail from TP for size and weight about this time last year when i bought them... four or five months later we got the 5S4P 5300 that were almost 5 ounces lighter per set of two than what I had. Whatever you buy now will likely be updated soon with batteries... but if it works for your application, who cares?

Since you are asking about TPs, a couple sets of the 5S4P 5300s will work great with the AXI and any of the planes you choose. As far as the other batteries though... the Flight Powers are no slouch and I'm sure there wil be adapter cables for the balancers out soon. I should have a set by next week to try out.

With all that said, welcome to the dark side, you'll never go back!

Tom Messer

patrnflyr

My Feedback: (7)

Thanks again for your advice. I'm a realist and understand that I probably will never really get past Intermediate or Advanced so my plane requirements are a little different than most pattern pilots. Also, I doubt that I'll ever fly at the NATS so a little bit chubby shouldn't hurt. I personally like the way the plane flies a little bit overweight than underweight. We get the "honor" of flying in 15-20mph winds most of the year here in Lubbock and I think the extra few ounces keep it more stable.

I think I'll need two setups for the chargers/balancers/AD-DC convertors for charging these batteries. Also, I guess that I'll need at least 2-3 sets of batteries. What type of ESC? I'm partial to the Castle Creations setup. At what amperage, the 110? The price difference is negligible between it and the 85.

ExFokkerFlyer

My Feedback: (4)

I have used pretty much just Jeti ESCs and never had any problems with them. Have been tempted to try a CC 110 or even an 85 to be able to use the braking feature. I have heard of people having trouble with CC escs, but that is only on the 'other' website, RCGroups, have not read that from pattern guys, most people seem to like them quite a bit! The price is certainly right, and I like the idea of being able to update the firmware.

Many people are going with a Honda EU1000i generator or something similar. While I can see a use for it, and I did almost buy one off Ebay, it really not necessary. It is definitely on the 'nice to have list', but I'm doing fine with the two 12V deep cycle batteries. There are a couple of threads on here about those set ups.

Good luck.

Tom M

exverbrenner

hi patrnflyer

if you have the chance to start from a blank piece of paper, then i think we, who have spent the better part of 2k $ on TP5300's, kokam3200's, polyquest 3700's and all the other "wonderbatt's", should give you the proper state-of-the-art advice, take you by the hand and lead you straight to TP's new LiteStorm. 10S2P4200 will give you plenty of flying time, they weight only 30 oz. (don't believe that overweight crap, light airplanes always fly better. period) ok, some may now argue with me for hours over that one, i know. but heavy batt's are BAD weight, better invest in a good power supply for the servos and beefier servos are GOOD weight! back to the LiteStorms: they are bloody amazing, the voltage is rock steady under load, and they keep cool. and they work perfect with your charger/balancer combo. it's the new gen, so save the money and make the short cut!

cheers,

roger

btw, nothing wrong with your other choices, the OXAI would be mine if i had the dough, and AXI-outrunners are fine if you don't like the sound of the 30-year old kitchen aid in your mom's house, that's at least what i always tell wolfgang matt when i want to bug him...castle PHX110HV is my ESC, the 85HV blew, and this is another example of GOOD weight!

nuff wise ass stuff for t'day

Barye

My Feedback: (27)

You will be cutting it real close on time using the 4200s

patrnflyr

My Feedback: (7)

As far as cutting it close, even in the intermediate class?

Barye

My Feedback: (27)

The consensus for longevity purposes is to use only 80% pack capacity. So that is 3360. For me that is 8 mins flying time. TP does not recommend this pack for F3A

ExFokkerFlyer

My Feedback: (4)

I regularly fly the Master's sequence with my AXI using only 1800-2300 mah depending on which batteries i use, and that is flying for 7.5 minutes. A 9 minute flight will yeild slightly more, but never more than 2700 mah. I have a buddy flying FAI and using a Hacker getting similar numbers. Throttle management is the key... don't try to fly these things like a glow bird. I should add however, these numbers are significantly lower than what I was getting last year... part of the change is a much lighter airframe and a slightly different philosophy when managing my power.

4200 mah would be enough for Intermediate, Advanced, and likely Masters depending on your throttle management. One other thing to consider is the C rating of those batteries and how many amps your are pulling with your system. The Flight Power 3700s are rated for 20C max continuous. I'm not familiar with the Lite Storm brand name... could that be just the ProLites with a different name? Or is it something new that we don't have over here? So I'm not sure what the C ratings are...

If weight is not going to be a huge issue, the 5300s have plenty of capacity and weigh 39 ounces per set. Most of the ARFs you listed have made weight with these batteries without a problem. If weight is an issue then there are other options, Flight Powers, smaller TPs and the like. I am really liking my set of Flight Powers, they have much more oompf, and have ordered another set... but with only 12 cycles I can't attest to longevity yet. My TPs have a lot of use on them and still going strong...

OhD

I am really liking my set of Flight Powers, they have much more oompf, and have ordered another set... but with only 12 cycles I can't attest to longevity yet. My TPs have a lot of use on them and still going strong...
[/quote]


I'm having trouble understanding why you use less energy with one set of batteries vs. the other. You either are getting lower voltage, (lower rpm), or less current, (less torque), or both. The efficiency of the motor and esc are not affected by the battery pack, so the loss must be in the battery. That would suggest less oompf.
Is there a big difference in weight so the airplane requires less energy? Is the cooling drag different? There must be an explanation.

Jim O

ExFokkerFlyer

My Feedback: (4)

Weight has something to do with it... and you are definitely going to feel 9 ounces weight difference. But the Flight Powers are taking on average 3-500 less mah per practice flight (sequence and land). I do feel weight plays a big part of it. BUT... the Flight Powers hold a higher voltage with a higher amperage at WOT. i have had to lower my throttle curve for the Flight Powers to keep things as consistant as possible as they are producing more power.

I have also logged flights with the Eagle Tree Systems e-logger with both sets of batteries in the same flight conditions and schedules. The Flight Power batteries use less current overall a peak of 56 amps on one flight versus 70 amps with the TP (flying the patterns, not showing off how much power I had...), all other conditions remained constant.

I am not saying I have all the answers, I rarely have more than questions actually, but these are the results I am seeing. I plan on using the e-logger again in a week or so to compare the results for the Flight Powers to see how they are performing or how I am adjusting to them. Also I will be able to have a broader set of data to reference.

FWIW, I test ran on the ground the Flight Powers versus the TP prolite 6000s with a 22x12.

TP went to 74 amps...

Flight Power at 89 amps when I shut it down and it was still climbing.


In the air I tested it with the e-logger (using a 20x13) and got this. In a vertical climb entered from cruising speed:

TP 74 amps, 31 V
Flight Power 84 amps, 33 volts

That's 478 watts difference with 9 ounces less weight... that would make a difference I think. Especially considering this test was done after the spin in a full Masters flight, and pulling straight up into a full power vertical climb for a few seconds before chopping the power and coming into land.

I'll have more data later if anybody is interested. Primarily I will use it to answer my own questions.

Tom

OhD

Tom, now that I've thought about it, I think I understand it, and I agree that you are on to something good. If we had a perfect battery the voltage to the ESC would be a constant 42 volts. The rpm would be Kvx42 minus losses in the ESC and motor. The equation stays the same with a real battery, but the 42 drops as a function of the current being used and the internal resistance of the battery. The higher the Ri of the battery the lower the rpm. So if your Flight Power packs have a lower Ri, the rpm will be higher at any throttle setting and you will throttle back to compensate. Thus you will use less energy. With the higher resistance battery you waste energy generating heat in the battery. Where does one get these packs?

Jim O

can773

My Feedback: (1)

Its still not that simple though as effective kV decreases with increasing load.

It takes a certain number of watts to the prop to complete a pattern...that is not going to change unless you a) lower the weight of your model, b) change your flying style. If you do neither, then the only difference I see is the voltage under load is slightly higher with the FP's....so the amps can be slightly lower for the same number of watts. In most cases this would nearly insignificant...but the drop of 9oz is most likely what is making the biggest change. Plus the fact that new packs are being compared to packs with over 100 cycles on them...Adam ran the same 6000 packs and when new at 72-73A he was getting around 35V out of them.

What we are missing here is rpm....that IMO is a crucial number to know to evaluate anything.

ExFokkerFlyer

My Feedback: (4)

If you are interested in the Flight Powers, check out www.rcmodels.ca The website shows out of stock on the 5S packs, but a shipment is due any day. Also adapters to use TP or other balancers on the Flight Powers will be available in the near future, I have a set right now that works pretty well.

exverbrenner

tom, i can attest the same findings comparing the polyquest 3700's versus my new litestorm 4200's (while litestorm is just a brandname hyperion uses for the TP2100's in configurated packs, i guess). i think there's one more factor missing in the solution of the equation: that's inertia, or kinetic energy, if you wish to call it that way. smooth pattern flying is full of that stuff. and if, at a given throttle position, your airspeed is 5 mph higher in level flight while entering a climb, you need less and shorter power bursts to accomplish that climb. and in p5 you have how many climbs..ah, a lot..! so 300mAh less for the whole flight makes perfect sense, that's only a few per climb, and the longer that weaker batt gets beaten up, the lousier it performs and the more you continue to shove that stick forward. you could explain the whole phenomen not monitoring your flight pack but simply monitoring your cumulated throttle position, bet?

roger

btw, barye...what monster are you chasing through the sky, eating up 3360 mAh in 8 min flying time...?[>:] i use exactly the same amount as tom does, but it took some time after daddy took the yamada (t-bird...) away

OhD

I think it is that simple. You could model the system as an ideal motor and an ideal battery with a resistor between them. Some of the resistance is in the real motor, some in the ESC and some in the battery. To get the same watts out you must put more in as the resistance increases. (any of the three).
You are right that decreasing the weight would reduce the power required but without more tests it is impossible to tell if that has a larger effect than the increased internal resistance. He could add weight with the lighter battery or could use a new TP 5s4p that is close to the same weight I believe of the FP. It would be interesting to know exactly how weight affects energy consumed in a typical pattern.

Jim O

exverbrenner

[quote]ORIGINAL: OhD

It would be interesting to know exactly how weight affects energy consumed in a typical pattern.




Hi Jim

let me try to answer that question with a power consumation figure i obtained yesterday. i went to the field and wolfgang matt was flying his new 2006 Oxai Beryll. i never tried P07 before so afterwards he coached me trough it. i flew my 20 lbs Raven with NeuMotors 2215/1,5Y 6,7:1 with APC 26 x 15, 10S4P8400 TP's. After the complete flight (which dured 9 min with 7.15 min of engine time above 30% stick), which was in quite hefty crosswinds (and you don't wanna chicken out with THE MAN behind you...), i charged 2450 mAh per 2P-pack, so roughly 5A went up in smoke. That's just 40Ah average consumation in P07 for a 20 lbs plane with a 3,5kW powerplant. And guess how much Wolfgang charged the 10-lbs-Beryll in same conditions: 2500 mAh! So weight has NO AFFECT or no side effect, it's linear: twice the weight, twice the power, and all those lies about the colibri/swan-effect...forget them! at least not in these categories! again, the key is kinetic energy, once those 20 lbs are on the move, you can point them anywhere, they just keep going

cheers

roger

OhD

Roger,

Very interesting. I'm surprised at the results. It says it takes twice the thrust in all attitudes (work = force x distance) assuming you did the same size maneuvers. Do the planes have the same wing loading?

Do you guys do any battery thermal conditioning before flying? What temp and how long a soak is required?

Say hello to Wolfgang for me. I used to compete with him in the 70s when we were young and had lots of dark hair. He looks like he still has his (hair).

Jim O

exverbrenner

dear jim, i'll forward your greetings to wolfgang, and yes, the guy never seems to get old[:@] and he's competing at the top level for 35 years now! and if, in a seldom uprising moment of mystic glory, you might, might, might beat him, his talented son roland pushes the limits even futher[>:]

yes, the wing loading is withing 3% at my advantage, and no, no thermal conditioning of the batt's. that is, if you don't count the seat heating of my audi on the way to the field in winter, that's where i usually put them[8D]

maybe the size of my figures were a bit smaller than his, the raven is slightly slower (my brain needs more time) than the average F3A, but not significantly. time used was within seconds. i know it's amazing, but it's a fact, no hidden APU somewhere

cheers


roger

PS: spy shot (lousy handy camera) of the new Liechtenstein weapon...!

OhD

Thanks Roger. Now I can rationalize why I got the heated seats in my Suburban. Living in Southern California makes it hard to justify.

By the way, that 33% electric Yak was impressive. Even some of my die hard gas friends with their 40% Extras said they'd like to have that set-up.

Regards, Jim

Dean Pappas

Hi Jim and Hi gang,
I did a fair bit of flying in 45F to 50F (,10C) conditions earlier this Winter, and don't have heated seats. My battery warmup procedure was to first build a styrofoam box for battery charging. I placed the fully charged battery in the foam box, and hooked up to the ESC, upon first reaching the flying field, and ran the motor at maybe 20 ~30A for two minutes. Then the batteries were immediately charged at 1C, and I continued to assemble the plane. The batteries would typically be at 85F (30C) just before flight. In sub 70F (20C) conditions I would stuff a small block of foam rubber into one of the two cheek ducts that fed the battery box with cooling air. At 45F, I half taped over the remaining inlet, in an attempt to keep post flight temps up to 100F (38C).

This was with a 63 A WOT setup. Okay, heated seats sure would be nice!

later,
Dean Pappas