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        Discussion Power Systems for Extreme Flight Fanatics!

#1 YellowJacketsRC Nov 04, 2011 11:46 AM

Power Systems for Extreme Flight Fanatics!
 
This thread is designed to post data, observations, questions and any other banter that is related to power systems (Motor, ESC/ BEC, Lipo, Prop) for Extreme Flight and 3D aircraft.

I have found that every build thread for every different plane contain lots of questions, and information that is discussed and re-discussed over and over. This thread is designed to consolidate this valuable information as well as to stream line the many different build threads out there.

HAVE FUN!

Please visit here for all results: http://www.rcgroups.com/forums/showp...&postcount=267

Also See Here:
http://www.rcgroups.com/forums/showp...&postcount=269

#2 Flazo Nov 04, 2011 12:59 PM

I bought the Hyperian - Z4020-16 Motor and looks like the Torque and is a bit lighter...

Yeah, I bought it for the MXS 60 inch when it comes out! I'm getting ready! : )

http://www.rcgroups.com/forums/showthread.php?t=1529103

picture-Vienquach

Vox Prop 15 x 6, 57 amps and watts about 1350.00 on Gens 2500mah 6 Cells

good luck

fred

#3 leespaddock Nov 04, 2011 01:09 PM

It's like the amazon of extreme flight power system info.
 
Way to go Dead. Bravo nicely done!

It would be super hip and cool if the extreme flight build thread owners of the world i.e. the Chris's, Tim's and Flops would point readers to this new extreme flight exclusive power system thread. This would satisfy the curious and avoid the ever present re-discussing of differing opinions, re-sharing data and re-dragging everyone through the same old :censored: matches. Then the build threads could focus on the plane. You have created one stop power system info shoppin! It's like the amazon of extreme flight power system info.

#4 JC Spohr Nov 04, 2011 01:13 PM

Quote:

Originally Posted by flazo (Post 19785668)
I bought the Hyperian Motor and looks like the Torque and is a bit lighter...

Yeah, I bought it for the MXS 60 inch when it comes out! I'm getting ready! : )



good luck

fred

Numbers man, we need numbers...

(Part numbers that is)

JC

#5 Trill Nov 04, 2011 01:39 PM

Xoar 15x6 PJN series
 
Lee,

Thank you for your research and results with the propeller testing.

http://www3.towerhobbies.com/cgi-bin...&I=LXAPTU&P=SM is one place to get the Xoar 15x6 PJN series prop.

Per the Xoar website, the PJN series is listed for electric and the PJA series is listed for gas. The only difference between the PJN series prop and the PJA series prop that I could see from the Xoar website is that the PJA series prop weighs 41 grams and the PJN series prop weighs 30 grams.
See http://www.xoarintl.com/props/model-airplane/PJN.html.

If you need a Xoar 15x7, the PJA series prop in a 15x7 is also available at the Tower website.

Hope this helps and happy landings!


Quote:
Originally Posted by leespaddock
Great information. Now can you tell me which vendor has a 15X7 and a 15X6 PJN Prop? I have scoured the web and came up dry. I guess as a last resort I could contact Xoar again and back track their wholesale history to their retail vendors, but since Tim just bought 3 of them I thought he could provide that info better than anyone.

Lee

#6 stgdz Nov 04, 2011 01:47 PM

After messing around with cheaper motors for the longest time I finally said screw it and got the airboss torque combo fir my 48" 300 exp. It wasn't that much more expensive and I am utterly happy with it.

Ooh and apc 12x6

#7 JC Spohr Nov 04, 2011 01:51 PM

Quote:

Originally Posted by stgdz (Post 19786053)
After messing around with cheaper motors for the longest time I finally said screw it and got the airboss torque combo fir my 48" 300 exp. It wasn't that much more expensive and I am utterly happy with it.

Ooh and apc 12x6

Same here... EF combo and APC 12x6E

JC

#8 Tom K. Nov 04, 2011 01:58 PM

I was contacted about this thread and it makes a lot of sense! I'll just post some info up here so I can refer back to it the next time it comes up:

Okay, here's my speech on calculating flight times. It works for me and I hope it makes sense

I have found that if you have a battery that is (let's pick a round number) 2000 mAh, when your battery is fully discharged, the volts per cell (vpc) is down around 3.2-3.5 (about where the average Low Voltage Cutoff is on most ESC's). I have devised a formula to help me calculate my flight times. Here's what I do:

Let's use a round number for this example. The hypothetical battery in this equation will be a 2000mAh battery.

I set my timer to count up (counts how long you've been flying) and then takeoff, trim the plane, and land, and right down the flight time. Then charge the battery and look at how many mAh's were put back in. What I do is subtract 25% of the full battery (500mAh is 25% of 2000mAh), and that gives me 1500 usable mAh's (that other 25% gives you a pass or so to go around if you have to, and the plane will still land at about 3.7-3.8vpc which is the ideal voltage to extend battery life).

So say you were up for one minute trimming. Say when you charged it the charger put back 500mAh. So now divide 1500 by 500(usable mAh by mAh used) and you get 3. That means that you can multiply your trim flight time (1 minute) by 3 (giving you 3 minutes) and you most likely will have a flight time that won't damage your batteries or bring the volts per cell below 3.7.

[Disclaimer: This is just my technique and is what I use to figure flight times.]

--Tom K.

#9 Tom K. Nov 04, 2011 02:03 PM

As far as the glow prop vs. electric prop debate:

Props that aren't made for electric motors are heavier. Heavier translates to more amps, more heat, and slower throttle response. The glow props are thicker at the hub and thicker all throughout so they can handle the power surges of a piston engine, and therefore, when modulating throttle, the electric motor has to overcome more inertial leading to more stress on equipment, i.e. possible magnet problems in the motor, overheating/overamping ESC is possible, and less overall cycles the battery will be able to live to see.

--Tom K.

#10 theKM Nov 04, 2011 02:31 PM

Quote:

Originally Posted by Tom K. (Post 19786163)
As far as the glow prop vs. electric prop debate:

Props that aren't made for electric motors are heavier. Heavier translates to more amps, more heat, and slower throttle response. The glow props are thicker at the hub and thicker all throughout so they can handle the power surges of a piston engine, and therefore, when modulating throttle, the electric motor has to overcome more inertial leading to more stress on equipment, i.e. possible magnet problems in the motor, overheating/overamping ESC is possible, and less overall cycles the battery will be able to live to see.

--Tom K.

electric props are better for electrics no doubt, but gasser props are simply less efficient than electric props. Electric props get to be exactly what the blade needs to be and nothing it doesn't. The weight of a gasser prop wont hurt your motor, ESC or packs, it simply wastes a few watts in spooling up and a few efficiency numbers off the top... their weight adds to gyroscopic precession for 3D pitch maneuvers, so they're typically not desirable compared to an electric prop. But there are some advantages to them... they're tougher, quieter and very smooth due to their inertia. One of the nicest electric setups I've seen is a Hacker A60 with a lightweight carbon gasser prop... super quiet, smooth, pure sweetness. If the mounting is set up to take the extra gyroscopic forces, they're really not shabby. just my $0.02 :)

#11 GPT Nov 04, 2011 02:45 PM

For those that have 2200 3S packs and are wanting a good value 3S setup for the 48" EXP birds. I run the 3DHS Omega 130g with a 14x7 Vox prop in my Edge and are very happy with it.

530 watts at 50amps static.

#12 YellowJacketsRC Nov 04, 2011 02:52 PM

Wow! YOu guys sure have jumped on board. Thanks!

#13 Tom K. Nov 04, 2011 03:22 PM

Quote:

Originally Posted by theKM (Post 19786389)
electric props are better for electrics no doubt, but gasser props are simply less efficient than electric props. Electric props get to be exactly what the blade needs to be and nothing it doesn't. The weight of a gasser prop wont hurt your motor, ESC or packs, it simply wastes a few watts in spooling up and a few efficiency numbers off the top... their weight adds to gyroscopic precession for 3D pitch maneuvers, so they're typically not desirable compared to an electric prop. But there are some advantages to them... they're tougher, quieter and very smooth due to their inertia. One of the nicest electric setups I've seen is a Hacker A60 with a lightweight carbon gasser prop... super quiet, smooth, pure sweetness. If the mounting is set up to take the extra gyroscopic forces, they're really not shabby. just my $0.02 :)

However if you are modulating the throttle, the extra weight of the prop translates into more inertia the motor has to overcome, therefore drawing more amps, producing more heat, and putting more stress on equipment.

--Tom K.

#14 theKM Nov 04, 2011 03:30 PM

Quote:

Originally Posted by Tom K. (Post 19786818)
However if you are modulating the throttle, the extra weight of the prop translates into more inertia the motor has to overcome, therefore drawing more amps, producing more heat, and putting more stress on equipment.

--Tom K.

the difference doesn't push things up to stress/damaging levels, it's like running an electric prop that's inch bigger without the reward of more thrust... there are things the prop will help and things it wont... throttle pulsing wouldn't be one of those things it helps, but for those who don't throttle pulse will find them pretty darn smooth. Either way electric props are generally very much the way to go, nobody wants to waste watts, but the story of damaging equipment by using gasser props isn't really the case. Lightweight gasser prop on an electric motor can have quite a sexy result.

#15 Tom K. Nov 04, 2011 03:41 PM

Quote:

Originally Posted by theKM (Post 19786877)
the difference doesn't push things up to stress/damaging levels, it's like running an electric prop that's inch bigger without the reward of more thrust... there are things the prop will help and things it wont... throttle pulsing wouldn't be one of those things it helps, but for those who don't throttle pulse will find them pretty darn smooth. Either way electric props are generally very much the way to go, nobody wants to waste watts, but the story of damaging equipment by using gasser props isn't really the case. Lightweight gasser prop on an electric motor can have quite a sexy result.

Whether or not it damages it, it stresses it more as the motor tries to overcome inertia. Also, from a performance standpoint, using a gas prop doesn't make any sense as electric props are more efficient, like you said. However, in theory at least, the added weight leads to more inertia the motor has to overcome to turn the prop, adding to possibly higher amps, more heat, shorter flight times, and shorter battery life.

--Tom K.


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