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F3A Results - SPOILER

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Old 08-07-2012, 03:35 PM
  #176
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When I charged my battery used in the last Unk, my Cell-Pro said there was 21% still left in the pack (charged to storage so don't know what mAh it took). The first Unk I had 23% and that was the average for my F's as well.
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Old 08-07-2012, 03:46 PM
  #177
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further info on the topic of motor torque vs. rotational speed:

http://lancet.mit.edu/motors/motors3.html#tscurve
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Old 08-07-2012, 03:55 PM
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I never charged more than 4100 in any flight in the finals, and used the same pack from the beginning of the semi's to the end of the finals, always charging at 20amps.
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Old 08-07-2012, 04:51 PM
  #179
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To all explaining the torque on a electric motor, I do agree 100% with the theory, no issues there, but please, try to fly a two meter pattern plane in electric then go with a YS, measure the RPM's on both, fly at the RPM's you know you need to fly straight and level, try to keep it at about 3500 to 4000RPM and pull to a vertical, then please report your findings.

I confirmed what I am saying by doing that.

Jason, what size of battery did you use?

Regards
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Old 08-07-2012, 06:41 PM
  #180
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Quote:
ORIGINAL: apereira
Jason, what size of battery did you use?

Regards
Alejandro, I don´t think that the batery capacity is important. If the model makes weight with a 10000000 amps batt. that´s the important thing. Everybody uses the capacity they think it will be enough to fly the secuence in every wind condition. You or all YS users uses a tank with enough fuel to finish the secuence. I don´t think you use a 50 cc fuel tank if you know you will run out of fuel.

Regards.
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Old 08-07-2012, 07:01 PM
  #181
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Quote:
ORIGINAL: protectedpilot




Which setup ispreferrable is what makes for a good horse race
My choice -is predicated on betting that batteries will keep improving.
Right now it's nip n tuck on having batteries which will work for the time/load needed .
Complicate the electricsetup (decrease efficiency) and the batteries have to supply more power -or be larger /heavier -or have greater capacity or C ratings
If batteries get 20% better at the same weight - then the edge for electric wins going away
My opinion.


We've been at odds several times, but I agree, with small reservations, with this statement. It is, indeed, nip tuck for the 7 to 8 minutes required. And I do believe we will cross that bridge one day, maybe tomorrow or the next day. Soon. And it made for a good horse race in Muncie last month. Exciting, even. And the electric won. But the IC made it a horse race. Enough so that there are several pilots at the top who are reconsidering their current choices.

I think the real bear for electrics right now is the power falloff during the flight. IC pulls even better as the flight progresses, due to expended fuel making the plane lighter. There certainly is no power dropoff at the end of the tank, until fuel is expended completely. But MY choice is predicated on what I like; nothing wrong with that, either. There are advantages to either propulsion, but if we see more patterns like the Unknown 1 in Muncie, in similar winds..... advantage IC. I can appreciate the absolute viability of electric flight, however.

One person that was not given enough credit in Muncie was AC Glenn. Last man up, winds absolutely howling by this time. Several of us judges were certain he would smoke a pack and force landing; but he didn't back off a single bit. I'd like to know the truth about how many pilots did smoke packs that day. AC certainly did, I'm sure Joseph did as well. All of them got the job done, but many of them paid for it later. The IC just had another day at the field.

Said it before, sayin it again; WOW! those guys really did a great job this year. It was thrilling to see.

Brian
I would argue that the main driver for people deserting IC power is reliability. There's little point having all that power if it's unreliable. It's better to finish than not finish at all IMHO...

Regards,
Jason.
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Old 08-07-2012, 07:05 PM
  #182
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Default RE: F3A Results - SPOILER

You guys keep discussing the issues at hand. I'm out flying and enjoying this 100+ heat. Lol

I'll throw in a kicker. I see an issue in density altitude flying on hot days then I do n the wind. Wind blows year round in Texas. I change my flying style a bit when it gets real windy, but I do like the options that are out there. I plan on using some of those options in the months to come.

Bottom line is that most pattern pilots that are serious or some that aren't so serious are looking for the perfect setup. Yes I said setup! Has Hebert has told me before, all planes aren't bad designs. They are poorly setup planes period. Yes the top guys and I include myself only because I have flown some trash out there before and have succes with it. Setup setup setup !!! Is the key for anyone!

I have learned from everyone out there from Chip to Tony to Hebert. I say Hebert because there are to many Bryan's out there. They all have great ideas and I respect all of them. Let's step back and learn about setting up our planes properly and leave all the other BS on the back counter.

Now I'm going back to burning some gas!
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Old 08-07-2012, 07:41 PM
  #183
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Quote:
ORIGINAL: RByrd

Now I'm going back to burning some gas!
You better be talking about flying that 124" pattern plane of yours getting ready for Clover Creek!
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Old 08-07-2012, 08:41 PM
  #184
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Default RE: F3A Results - SPOILER

Torque, rpm, Hp, kw ? Doesn't matter whether it comes from electric or glow.

The real key is finding what combination of the the above will give you at least 11lbs of thrust above what you need to overcome drag at cruise speed so you don't slow down in an upline AND naturally compensates for some of our poorly timed/co-ordinated throttle inputs to help with speed regulation.

I'd dare say that given the torque curve and diameter of prop that electrics run, that if you found yourself at the bottom of an upline with no airspeed, an electric setup would have the edge over IC to get you out of trouble and back on track, where that same torque curve would see you running out of puff when pushing out into a strong headwind at the top of an upline when you need the extra 20-30km/h airspeed to maintain that constant speed look.

At the end of the day, the schedule designers decide which powerplant is to have the advantage. Putting snap-rolls at bottoms of loops and in uplines to bleed off energy worked well to kill off two-strokes.

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Old 08-08-2012, 12:21 AM
  #185
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Default RE: F3A Results - SPOILER


Quote:
ORIGINAL: apereira

To all explaining the torque on a electric motor, I do agree 100% with the theory, no issues there, but please, try to fly a two meter pattern plane in electric then go with a YS, measure the RPM's on both, fly at the RPM's you know you need to fly straight and level, try to keep it at about 3500 to 4000RPM and pull to a vertical, then please report your findings.

I confirmed what I am saying by doing that.

Jason, what size of battery did you use?

Regards

Hi,
You should repeat your test again.
When I did this I got just the opposite result to what you seem to be saying.
I did this test when I first flew electric F3A.
I did it because I could not believe the way the electric would continue to climb at moderate throttle settings.

The YS just stalled inside 100ft. It would start to tail slide and or slip out to the side.

What I did not know at the time was that the YS just continued to make the same power or a bit less as it loaded up while the electric simply made more power because as the prop loaded up the motor increased the Amp draw.

Actually I think this may be the salient point in the 'low down torque ' discussion we seem to be having.

It's funny how you got the opposite result - must be the thin air at altitude that is affecting something .

Brian
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Old 08-08-2012, 01:21 AM
  #186
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Default RE: F3A Results - SPOILER

Quote:
Hi,
You should repeat your test again.
When I did this I got just the opposite result to what you seem to be saying.
I did this test when I first flew electric F3A.
I did it because I could not believe the way the electric would continue to climb at moderate throttle settings.

The YS just stalled inside 100ft. It would start to tail slide and or slip out to the side.

What I did not know at the time was that the YS just continued to make the same power or a bit less as it loaded up while the electric simply made more power because as the prop loaded up the motor increased the Amp draw.

Actually I think this may be the salient point in the 'low down torque ' discussion we seem to be having.

It's funny how you got the opposite result - must be the thin air at altitude that is affecting something .

Brian
This was my observation exactly. Not versus a YS but a gasser, however it was plenty enough to lure me over to the dark side!
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Old 08-08-2012, 02:16 AM
  #187
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Default RE: F3A Results - SPOILER

Contest day in any sport involves a play of chance. This is especially true in aviation (and boating perhaps) where the craft moves through a fluid medium that is not exactly the same for each heat. The competitors accept that, prepare well anticipating both the piloting skills and equipment needed to carry the day, and have their go when their turn comes up to fly. Sometimes things break or fail, as in auto racing, all part of the sport: The thrill of victory / agony of defeat thing we learned about watching TV as kids. Given that the guys at the top who are flying FAI well enough to inspire us all are also experienced enough to select good parts, assemble those into their airframe of choice, tune and trim to near perfection, and practice deliberate technique that compliments their aircraft in the anticipated conditions, I hope we can take those variables off the table for a NY minute (all you FAI flyers are awesome to me): Without getting too personal about the pilots who flew their pants off, please what precisely happened at the Nats this year with the conditions that so sorely tested the aircraft? Anything we truly learned that informs improvements for the future? And can this be discussed briefly without undue bragging or painful insults? These stories are great learning opportunities for those of us climbing the classes and I thank all for sharing here with the lesser mortals LOL. Good stuff. You guys rock!
Thanks also to Ed Alt for posting that link about electric motors. Very interesting graph giving insight into where peak power is expected. Is that peak power band really so different from IC, in theory? Another topic for another thread no doubt, but it's nice to get some common language cleared up.
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Old 08-08-2012, 04:48 AM
  #188
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Ricardo, I am asking because if a battery is run very close to its capacity the temperature of the battery will go up increasing the IR and the battery performance will reduce, it is NOT the same to use 4400 mAh on a 4400mAh battery that running 4400mAh on a 5300mAh battery.

Brian I have never seen a YS stalling like you said, ever, on the 175 you can climb unlimited at 1/2 or a tad above half power, what you are saying is not true about the YS, have not experience that ever, it will be interesting if someone else had that problem, and what was your YS setup?

Regards
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Old 08-08-2012, 04:55 AM
  #189
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Now that I see people started to make things up, this just became to be a pissing contest...... We'll see what happens in South Africa, I going to keep flying electric and YS, as in turn I do have the best of both worlds.

Regards
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Old 08-08-2012, 05:02 AM
  #190
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Default RE: F3A Results - SPOILER

In the final unknown round which was the worst wind and longest unknown, I only put back 4058 into a 5000mah pack. After both of my finals pattern flights I only used about 3500 mah each flight.
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Old 08-08-2012, 05:25 AM
  #191
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Default RE: F3A Results - SPOILER

Quote:
ORIGINAL: apereira

Ricardo, I am asking because if a battery is run very close to its capacity the temperature of the battery will go up increasing the IR and the battery performance will reduce, it is NOT the same to use 4400 mAh on a 4400mAh battery that running 4400mAh on a 5300mAh battery.

Brian I have never seen a YS stalling like you said, ever, on the 175 you can climb unlimited at 1/2 or a tad above half power, what you are saying is not true about the YS, have not experience that ever, it will be interesting if someone else had that problem, and what was your YS setup?

Regards
Hi,
You did not say at 1/2 or a tad above. so that it would climb unlimited.
You did say 'fly at the RPM's you know you need to fly straight and level, try to keep it at about 3500 to 4000RPM '
I understood this to mean 'just' enough to fly straight and level.

If you set either so that they will climb unlimited they will 'climb unlimited'.
That would just prove that you 'set' it climb unlimited.
In any test one does it is a must to set up controls so as to ensure the test is valid.
Otherwise you will get the result you set out to get.

I'm not sure who is 'making things up'.
I am sure that some of us can make the mistake of judging others by our own standards.

Repeat your test and let us know the outcome.

Brian

Edit for punctuation.

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Old 08-08-2012, 05:31 AM
  #192
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Hi,
I think the goose must have laid a few eggs before it was consigned to the oven .

Brian
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Old 08-08-2012, 05:39 AM
  #193
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Is it true that the brushless motors used in pattern planes are mostly AC motors? The torque curve of an AC motor can differ from a DC motor. Check out this URL: http://www.jmag-international.com/ca...eedTorque.html.
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Old 08-08-2012, 05:52 AM
  #194
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None of the finalist on this thread used more than 80% capacity on their packs in that wind. I was standing right with Chip when he finished his last flight and went back to the van. Chip said "Well, we learned something here. The contra is great for P and any other class at any given time. When you get to this level and have F and the unknowns in conditions such as this, it becomes tough". I don't believe anyone smoked a pack at the finals at all. Chip may have had other elements in play here as well which we do not know. There are obviously pros and cons to each. IC provides great power, cool sound, longer flight times and, quite honestly, the ability to have a little heavier air frame because you don't have to weigh with fuel. Electric provides (with the right motor) all the torque in the world at whatever RPM, less vibration, longevity, good braking (if applied properly). By AC, Chad and Jason giving their mah, it's obvious that capacity should not be in the equation. Those conditions were extreme but obviously, doable. It still....after all this time...boils down to choice and which "devil" you decide to live with. Bryan Hebert, one of the most gracious pattern fliers you'll ever meet, likes his YS. Andrew, AC and others love their electrics. Chip "may" be switching because Chip is an innovator. He flies and tries it all. He's always searching for the best setup for him. He hasn't been in this game as long as he has "just because". He used to fly the bipe (remember the Scandalous) and he's tried just about everything else. This is important and just like the rest of the top fliers. I'm not sure it's fair to rest the weight of the pattern world on his shoulders however. We don't hear any other of the finalist saying "that's it, I'm switching!". If Chip does switch, Chip is switching because that's what's good for him and his career.
At the Worlds next year, you will see Brett, the French team and many others flying IC. You will also see plenty of electric doing quite well. The choice should be what you, as a pattern flier, are comfortable with and what helps you fly the best you can.
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Old 08-08-2012, 06:12 AM
  #195
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Default RE: F3A Results - SPOILER


Quote:
ORIGINAL: nonstoprc

Is it true that the brushless motors used in pattern planes are mostly AC motors? The torque curve of an AC motor can differ from a DC motor. Check out this URL: http://www.jmag-international.com/ca...eedTorque.html.
They are brushless DC, our motors are not AC induction motors, which would be more typical of industrial large motors.

http://en.wikipedia.org/wiki/Brushle...electric_motor

All the motors we use operate on that principle, and are all essentially the same with the exception of # turns, winding wire, #poles (which dictates #magnets) and physical size.

Someone can correct me if I got it incorrect.
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Old 08-08-2012, 06:13 AM
  #196
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I think sometimes the most difficult part is how to explain everything correctly, then biased have their input, the right and the wrong, so it will always be difficult to get to an agreement, all this started because Bryan wanted to share his story, then it seems like some people are just waiting to see where can I get in and start a fire, with any info available, from true to whatever, and the opinions without first hand experience with a given equipment is very obvious some time, this will never change.

CLRD2LAND, I think you summarized all pretty well there, will see what happens in the future.

Regards
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Old 08-08-2012, 06:16 AM
  #197
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Default RE: F3A Results - SPOILER


Quote:
ORIGINAL: danamania

Without getting too personal about the pilots who flew their pants off, please what precisely happened at the Nats this year with the conditions that so sorely tested the aircraft? Anything we truly learned that informs improvements for the future?

It was windy.

I learned three things....
a) I need to practice more
b) Flying right after Andrew when he is kicking our asses really sucked, which turns me back to point a)
c) Don't assume that a "rolling horizontal eight with 4 rolls" is really in the horizontal plane....they are just messing with you. Its actually in the VERTICAL plane! If in doubt ask before you get to the Nats! Doing it in the VERTICAL plane makes it MUCH MORE DIFFICULT!
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Old 08-08-2012, 06:29 AM
  #198
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Default RE: F3A Results - SPOILER

You are correct in my opinion Chad,

The confusion comes from the fact that our brushless motors run on DC with AC type of winding, but they are DC for sure.

Regards
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Old 08-08-2012, 06:30 AM
  #199
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Default RE: F3A Results - SPOILER

Quote:
ORIGINAL: apereira

I think sometimes the most difficult part is how to explain everything correctly, then biased have their input, the right and the wrong, so it will always be difficult to get to an agreement, all this started because Bryan wanted to share his story, then it seems like some people are just waiting to see where can I get in and start a fire, with any info available, from true to whatever, and the opinions without first hand experience with a given equipment is very obvious some time, this will never change.

CLRD2LAND, I think you summarized all pretty well there, will see what happens in the future.

Regards
Hi,
Actually post 17,by Chip, was the starting point, for me and most others.
Until then it was on topic , whatever that was .

Brian
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Old 08-08-2012, 06:38 AM
  #200
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Your right, I was confused with Bryan's thread.
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