WattFlyer RC Electric Flight Forums - Discuss radio control eflight

WattFlyer RC Electric Flight Forums - Discuss radio control eflight (http://www.Wattflyer.com/forums/index.php)
-   Warbird Electrics (http://www.Wattflyer.com/forums/forumdisplay.php?f=50)
-   -   Hanger 9 .60 F4U Corsair (http://www.Wattflyer.com/forums/showthread.php?t=73561)

70sflyer 04-14-2014 05:23 PM

Hanger 9 .60 F4U Corsair
 
Have hanger 9 .60 corsair ready to fly,I was wandering if any one had an issue with heat.There is no place for heat to exit from fuselage.I thought I could make a hole behind tail wheel but the balsa wood is very thick.Maybe it wont be a problem,but any suggestions would be appreciated.

kyleservicetech 04-14-2014 06:30 PM

Quote:

Originally Posted by 70sflyer (Post 945439)
Have hanger 9 .60 corsair ready to fly,I was wandering if any one had an issue with heat.There is no place for heat to exit from fuselage.I thought I could make a hole behind tail wheel but the balsa wood is very thick.Maybe it wont be a problem,but any suggestions would be appreciated.

H'mmm
With a 65 inch wingspan, 8 pound airplane, you'd be running about 1000 to 1500 watts or so up front. And if the power systems include LiPo batteries, keeping air circulation for the motor/esc/battery pack is important. Hot LiPos generally indicates short LiPo battery life.

I'd definitely find a way to allow air to flow through the front of the model, over the battery pack and out the bottom of the model somewhere. I've covered those holes with window screening on one or two of my models, but not certain that is worth the effort. My models don't have "Holes" for air exit. It's usually better to provide a slot under the fuse for the air to exit. Something on the order of an 1 1/2 inches wide, and 4 inches long. It all depends on how hard you're pushing your motor/esc/battery pack, compared to the ratings of your motor/esc/battery pack.

I'm running those over weight, over sized, under voltage A123 packs in my various models. These battery packs are built into the model, and are charged in the model. Because of the greater surface area of the A123 cells, (compared to a similar LiPo battery) along with their aluminum jackets, they don't get hot. I've actually had these batteries get heated up from sitting in the sun, then cool off during a flight. I've got two 12S2P packs, three 6S2P packs, two 6S1P packs, and two 4S1P A123 packs in my various models. All still put out the same volts/amps/watts as when brand new, and some are 5 years old.

The more air the better, but a real blast of air through the model really isn't required. Just a good airflow through the model so as to not trap heat from the battery during flight.

Out of curiosity, what do you have for motor, prop, esc and battery packs?

Maybe you'll find something useful in these threads?

Thread on 70 size glow engine conversion to electric
http://www.wattflyer.com/forums/showthread.php?t=45222

Hacker 6S2P A123 powered Models
http://www.wattflyer.com/forums/showthread.php?t=44686

Hangar 9 Kantana Model
http://www.wattflyer.com/forums/showthread.php?t=68844

70sflyer 04-15-2014 01:55 AM

Dennis,My setup is AXI 4130/16 with,16X8 prop, 5000mAh 45c thunder power Lipo batt,CC 80 ESC and 10 A BEC.I do have 2,4600 mAh 3S2P A123 battery's I could put in but it is setup for lipo now.Maybe vent hole would be easier.Thanks Dean

kyleservicetech 04-15-2014 04:44 AM

Quote:

Originally Posted by 70sflyer (Post 945488)
Dennis,My setup is AXI 4130/16 with,16X8 prop, 5000mAh 45c thunder power Lipo batt,CC 80 ESC and 10 A BEC.I do have 2,4600 mAh 3S2P A123 battery's I could put in but it is setup for lipo now.Maybe vent hole would be easier.Thanks Dean

Do you have the AXI motor all ready??

If not, IMHO, the Hacker A50-12S motor is a better motor, and costs some $15 less than the AXI 4130/16 motor.

I've got three of the A50's, running them on 6S2P A123 packs, similar to a 5S 4500 Mah LiPo battery. These motors haul my 8 pound models straight up, out of sight.

These Hacker setups turn a 15X10 APC-10 prop at 7700 RPM, pulling 70 Amps and about 1200 Watts, putting 1050 Watts on the prop. These Hacker motors are only slightly warmer than ambient temperature after a flight. Motocalc predicts some 88% efficiency at 70 Amps, compared to only 72% efficiency for the AXI motor.

Per Motocalc, the AXI motor with your 16X8 prop, with a 6S LiPo will have about 900 Watts input, putting 700 Watts on the prop. Motocalc predicts 6500 RPM with the AXI and the 16X8 prop.

For what it's worth, motocalc predicts a climb out rate of 3100 Feet per minute straight up with the Hacker motor, versus 1600 Feet per minute at 45 degrees climb out with the AXI. That would be a 5S LiPo for the Hacker, and 6S LiPo for the AXI.

The difference between the two motors is the motor winding resistance. Its 0.63 ohms for the AXI, and 0.016 ohms for the Hacker.

IMHO, A123 cells are great, last a long long time, can be stored at full charge for months or years. With a high powered charger, they can be charged in 15 minutes, leaving the battery pack in the model. But they will never match the performance of a decent LiPo battery, in regard to voltage per cell, weight and physical size.

70sflyer 04-17-2014 02:34 AM

Dennis,yes I have the motor installed but may change to the Hacker.I have other planes with Hacker motors and they are fine.Thanks for your help.

kyleservicetech 04-17-2014 06:09 AM

Quote:

Originally Posted by 70sflyer (Post 945630)
Dennis,yes I have the motor installed but may change to the Hacker.I have other planes with Hacker motors and they are fine.Thanks for your help.


I've also got one Hyperion motor that is running at about 500 Watts. Nice quality type motor. Same quality as my similar sized, much more expensive Hacker A40-10L. Hyperion does make much larger motors, and at lower prices than the Hackers.

I don't have this one, and don't know if it comes with a prop adapter. But that price is nice.
http://www.allerc.com/hyperion-zs402...or-p-4713.html


All times are GMT +1. The time now is 07:43 AM.

Powered by: vBulletin
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 2005 WattfFlyer.com
RCU Eflight HQ

Page generated in 0.08112 seconds with 13 queries