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Old Mar 03, 2013, 05:06 PM
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It's supposed to have a fantastic governor (YGE clone) and I'm going be trying that out next.

The second flight of the 6S pack at the field revealed the first anomaly so far. The ESC didn't want to spool up at first. Originally I thought the pack voltage was too low but now I think the ESC didn't like coming out of throttle hold to a 60% throttle curve (mid stick). I had to flip throttle hold again, then off, then she spooled up, but now the ESC constantly beeps 6 times when not turning the motor, so I'll have to investigate. But, she flew great for the 4 minutes in the 1200RPM range. Very quiet, and still quite controllable.

I think I'm going to stop at 1250 with the 12T pinion. The heli is flyable at that RPM, but I may switch to the 9T now and raise those throttle curves back up. The ESC may be politely hinting for me to do that now I have to say, the possible RPM range with the 12T and the ESC's active freewheeling is very impressive. I may re-run some of the flights with the various RPMs & batteries and see how the power requirements differ with a smaller pinion and higher motor RPMs.

My next flight, back to the series 3S packs, backyard hover, I noticed the soft start spun the heli up to a head speed slightly higher than 1250, and it wasn't until I actually lifted off that the RPMs dropped down to where they were supposed to be. The rest of the flight was fine. Again, maybe a sign not to keep pushing things ...

I'll have stats when I recharge the packs, but not tonight - word has it another snow storm is due to arrive tomorrow ...

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Old Mar 03, 2013, 05:18 PM
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Quote:
Originally Posted by FR4-Pilot View Post
Definitely

Just finished a 4min backyard test hover at 1250-1200 RPM - Sweet! (I've got to get one of those EagleTree loggers). This is half of the RPM/Voltage sag as seen when running at 1350-1250 on the same 6S pack.

Going to go to the field and fly a 4 minute test forward flight on the remainder of the pack's charge

(6S 3300 40C, 550mm Asymmetricals, 62.5% throttle curve)

Now the real test relative to the blades would be to test some 550mm fully symetricals using the same 6S pack. I say this because I have found that some designs of fully symmetrical blades could be more efficient then some semi-symetricals. .
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Old Mar 03, 2013, 05:23 PM
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Now the real test relative to the blades would be to test some 550mm fully symetricals using the same 6S pack. I say this because I have found that some designs of fully symmetrical blades could be more efficient then some semi-symetricals. .
I agree - the Edge 523mm symmetricals are very efficient. I have two sets of EcoPower 550mm that I got from Amain - other than those and I'm out of blades to try.

I would also like to try the 515mm asymmetricals too, but those will have to wait - the datalogger is next in line for purchasing

I was debating which ones to get - the 515s or 550s. Ultimately I decided on the 550s for maximum lift and best chance for lowest head speed, but the 515s would have been better for longer flight times/less power draw. I wanted both, but ...

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Old Mar 03, 2013, 06:05 PM
If I build it, it will fly
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The ESC was likely confused about cell count due to the mid range voltage. Is it set for *auto* or locked into *li-poly* ?

For consistency sake all testing should be done from a full pack anyway. As they say in the automotive world "the bottom 1/4 is the smallest 1/4 of the tank."


side note: do you think a 550+ 1300kv could be rewound into a 600A 800kv? Seems to be the same bell & stator. Does anyone have both that could confirm size / pole / tooth count internally?

~psguardian
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Old Mar 03, 2013, 06:18 PM
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I'll have to get the program card back out but I believe I told the ESC to expect a 6S pack, which I see your point, could be confusing when starting out with a partially-spent pack.

I have a 550 Lightning 1300kV that I haven't used - don't know how it compares to 600A 800kV. I have the 650A 800kV - do you mean that one, or is/was there another 800kV in the history of Century motors?
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Old Mar 03, 2013, 06:33 PM
If I build it, it will fly
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You're right, I mean Century 650A 800kv lol. The 600A is their 1110kv.

Could you peek in the bell & get a mag count, stator tooth count, & overall dimension? Not sure it's doable while installed, don't want to ask you to pull it either LoL. I am liking your high voltage (high for a 3s flier) low rpm results, $100 motor not in the cards, but a couple spools of mag wire could be.

~psguardian
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Old Mar 03, 2013, 07:23 PM
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Well, I'm going to have to pull it to change the pinion - I'll be glad to measure & count things, & take a few pics too Maybe sometime this week ... ?

The field flight from today (when the ESC didn't want to start) had a beginning headspeed of 1200 and ending of 1140. A benefit of not using the gov. yet at least allowed me to see some lower headspeeds (as a result of voltage sag) than originally set by the throttle curve. At least I know that the heli is also flyable down at 1140, even though the test was for 1250
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Old Mar 03, 2013, 07:37 PM
If I build it, it will fly
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Numbers are all i would NEED for the winding calc, but pics would be GREAT! Thank you very much.

Knowing that it can be flown down low like that is a bonus, but the hover prick must be creeping towards 5° by now lol. Not much in reserve for an emergency pitch pump in car if down draft i would think. But them i'm not the one flying either, Phoenix won't even take off if i set headspeed down below 1600-1800... Having a really hard time with settings in that sim.

I have weeks before I'll be in a position to rewind, so whenever you have time.

~psguardian
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Old Mar 03, 2013, 07:49 PM
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I'll double check next time, but (with the SpinBlades at least) there still seems to be a fair amount of collective left to ascend decently from a hover. I would suggest not trying the low RPMs in windy conditions - maximize the chances for success on calm days But changing pinions might make a difference in response time here ... ?

I haven't tried in Phoenix to reduce head speeds, but I did in RealFlight 6.5 - you can even define the airfoil shape too (symmetrical vs asymmetrical). On one model I observed lower amp draw hovering right side up compared to inverted when using an asymmetrical shape - that was pretty cool. You can even choose an airfoil that is basically a paint stick - no curve at all, if you want (I did) and the heli flew very well. That's got me puzzled though ... And you can change motor kV, batteries, # of cells, capacity, blade type, gov/no gov & settings, etc. and it all works very realistically.

I only recently stumbled on those settings in RF - Phoenix may allow those settings to be tweaked too, I just haven't found them (yet) ...

And no problem with the motor - glad to help
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Old Mar 03, 2013, 08:13 PM
If I build it, it will fly
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I need to just start over from a blank model memory & find some useful website for Phoenix. getting negative pitch on a ccpm shouldn't be this difficult.

The paint sticks will do the job on pitch alone, just not as well as a real airfoil LoL. Angle of attack is on their side.

~psguardian
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Old Mar 03, 2013, 08:30 PM
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For Phoenix on my DX6i I had to create a model memory and set the swash type (in the Dx6i) to single/90°/no ccpm. Evidently Phoenix wants all the channels separate coming from the controller. Just something to check ...

Here's a snippet from today's flight - 1200 to 1140 RPM. The blades sound awesome when she passes by - and she really handled very well. There was a bit of wind (not too much) as well. I've never flown this much in the winter/cold as this year doing these RPM tests - I am hooked

Another Heli Video (1 min 11 sec)
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Old Mar 04, 2013, 12:51 PM
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Have not flown my heli's in about a month. My Jet Ranger is RTF. I am afraid to flyl it until I put a few flights on somehting else. Hopefully this week. I will post a pic of the Jet Ranger later. If you are considering a Swift scale, they look great!
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Old Mar 04, 2013, 01:37 PM
If I build it, it will fly
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I would love one of those, cannot afford though.

~psguardian
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Old Mar 04, 2013, 08:07 PM
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Quote:
Originally Posted by Greybird View Post
Have not flown my heli's in about a month. My Jet Ranger is RTF. I am afraid to flyl it until I put a few flights on somehting else. Hopefully this week. I will post a pic of the Jet Ranger later. If you are considering a Swift scale, they look great!
I will look forward to seeing that. Hope you get some videos.

I think that when you are ready to post the pictures and videos that you start a separate thread giving us all the info....mechanics, fuselage, motor, esc, battery pack, blades etc.
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Old Mar 05, 2013, 03:04 PM
If I build it, it will fly
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FR4, when you do get a look at your motors could you also see if you can determine how the winds are terminated please? IF it's visible, don't pull the cans on my account alone.

The info I've been able to find so far says the can should have 8 magnets, the stators should have 12 arms, and they are probly delta terminated (no central joint, just three bunches that become esc leads).

IF these specs are correct:
I could re-terminate the 1110kv, from delta to star, & lower it to approx 640kv (1110/1.73=641.61) without affecting power handling.

I could re-terminate the 1300kv, from delta to star, & lower it to approx 750kv (1300/1.73= 751.45) the motor would still be 5s safe | 6s experimental, but the lower kv will actually reduce amp load by about 25% & allow the ESC to run at a higher thr/eff.

Ex. in dark horse advanced - no fudge - mid pack voltage
6s, 10t pinion, 1300kv, 90% eff, gov 1400hs, 10°pitch =
throttle 67.99% | sys eff 74.26% | thrust 6882.27g | 52.83 amp
6s, 10t pinion, 750kv, 90% eff, gov 1400hs, 10°pitch =
throttle 93.49% | sys eff 85.86% | thrust 6908.09g | 43.29 amp

This would be a real win for me, could keep the 1110kv for performance later & use the re-terminated 1300kv (now light duty 750kv) for training/scale flights.

~psguardian
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