help me figure out my EP system
#1
Member
Thread Starter
Join Date: Aug 2012
Location: Boise ID
Posts: 36

I just bought the GP Electrostik. THey reccommend a 42-40 brushless with a 3600mah 3S and 11x8.5 prop. I have a 42-40 brand new that is rated 50A cont and 60 amp max (850KV). If i use a 40 or 45amp ESC, will I burn up my motor? or could I use a Eflite Park 480 (1050KV) and 40amp ESC with 3S 2200 pack? I need help. I don't want to burn up any motors or kill my li-pos...
#2

I just bought the GP Electrostik. THey reccommend a 42-40 brushless with a 3600mah 3S and 11x8.5 prop. I have a 42-40 brand new that is rated 50A cont and 60 amp max (850KV). If i use a 40 or 45amp ESC, will I burn up my motor? or could I use a Eflite Park 480 (1050KV) and 40amp ESC with 3S 2200 pack? I need help. I don't want to burn up any motors or kill my li-pos...

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#3
#4

Hi Here are the specs on the eflite 480 motor, stay with in the specs given and you will be fine. use the 40 Amp Esc. your 3S 2200 pack needs to be at least 20C rated to give you a 44 amp lipo, 2.2 amps = 2200mah x C rateing 20 = 44 amps, a bigger lipo than 2200mah would be better to use.
Specifications
Type: Brushless Outrunner
Size: Park Flyer
Bearings or Bushings: Ball Bearings
Wire Gauge: 16
Recommended Prop Range: 10x7 to 12x6
Voltage: 7.2 to 12
RPM/Volt (Kv): 1020
Resistance (Ri): .06 ohms
Idle Current (Io): 1.10A @ 8V
Continuous Current: 22A
Maximum Burst Current: 28A (15 sec)
Cells: 6 - 10 Ni-Cd/Ni-Mh or 2 - 3S Li-Po
Speed Control: 25A to 40A Brushless
Weight: 87g (3.1 oz)
Overall Diameter: 35mm (1.40 in)
Shaft Diameter: 4mm (.16 in)
Overall Length: 33mm (1.30 in)
Specifications
Type: Brushless Outrunner
Size: Park Flyer
Bearings or Bushings: Ball Bearings
Wire Gauge: 16
Recommended Prop Range: 10x7 to 12x6
Voltage: 7.2 to 12
RPM/Volt (Kv): 1020
Resistance (Ri): .06 ohms
Idle Current (Io): 1.10A @ 8V
Continuous Current: 22A
Maximum Burst Current: 28A (15 sec)
Cells: 6 - 10 Ni-Cd/Ni-Mh or 2 - 3S Li-Po
Speed Control: 25A to 40A Brushless
Weight: 87g (3.1 oz)
Overall Diameter: 35mm (1.40 in)
Shaft Diameter: 4mm (.16 in)
Overall Length: 33mm (1.30 in)
#5
Super Contributor
Join Date: Oct 2005
Location: N.Staffs, UK
Posts: 2,350

If the plane weighs 3.5lb then a 250 watt EFlite480 might be a bit feeble....unless you just want to putter gently around. Much better to use the 4240 with a decent 60A ESC.
BTW if you use an ESC which is too small it will be the ESC that burns up not the motor or lipo. I.e. if motor is drawing 50A and the ESC can only take 40A....dead ESC
.
Steve
BTW if you use an ESC which is too small it will be the ESC that burns up not the motor or lipo. I.e. if motor is drawing 50A and the ESC can only take 40A....dead ESC

Steve
#6
Member
Thread Starter
Join Date: Aug 2012
Location: Boise ID
Posts: 36

Thanks for the tips. Looks like the 42-40 with 60A esc and whaddya think, a 3600maH 3S? Plane supposed to weigh in at 3.5 all up. I bought a luggage scale to hang it from and weigh it all up, as well as measure the static thrust. For good aerobatic (but not 3d) what do you guys think? About 1:1 thrust ratio?
#7
Member
Join Date: Apr 2012
Posts: 152

You'll be in good shape with that 42/40-850kv. You can either use it with a larger prop than 11x8.5 OR use 4s on it with the 11x8.5 prop.
The stock set-up from GP (rxr) is 3s and 1000 kv with the 11x8.5 prop. It just isn't ok to use the stock 45 amp esc. Not because it isn't big enough , but because it has no adjustable timing and the factory combo squeals badly. Mine pulls 40 amps on a terrible battery and is about 400 watts I think. I fly very mildly for 15 minutes.
I about ready to convert my stocker to 4s and I will use a very similar motor (42x40 750-910kv) I don't think I'm going to spin my 1000 kv with 4s.
The stock set-up from GP (rxr) is 3s and 1000 kv with the 11x8.5 prop. It just isn't ok to use the stock 45 amp esc. Not because it isn't big enough , but because it has no adjustable timing and the factory combo squeals badly. Mine pulls 40 amps on a terrible battery and is about 400 watts I think. I fly very mildly for 15 minutes.
I about ready to convert my stocker to 4s and I will use a very similar motor (42x40 750-910kv) I don't think I'm going to spin my 1000 kv with 4s.
Last edited by nidly; 12-25-2012 at 02:37 PM.
#8

Henry
Electrostick
Heads Up 4248-08 Motor Flies on 4 cells Floats
#10
Member
Thread Starter
Join Date: Aug 2012
Location: Boise ID
Posts: 36

thanks to all for your help. my electrostik will be arriving friday and I can't wait to get her out of the box. found a 60a esc that i will use, just need some bigger lipos now. any reccomendations on a metal gear mini servo?
#11
Member
Thread Starter
Join Date: Aug 2012
Location: Boise ID
Posts: 36

thanks, Henry. I decided to go with a 42-40 1000KV i had lying around. I bought a 3S 2200mah 30C batt to let me get up to 66 amps. i'm worried that I won't get much flying time tho. what do you use on your stik?
#14

http://www.headsuprc.com/servlet/the...s/1/Categories
http://www.headsuprc.com/servlet/the...-for-30/Detail
here is a power up 32 from heads up rc, see if that will fit your plane, there is a pic that shows the size of the motor and mounting.
http://www.headsuprc.com/servlet/the...2-Sport/Detail
How Do I Mount My Outrunner Motor
http://www.wattflyer.com/forums/showthread.php?t=39483
#16
Member
Thread Starter
Join Date: Aug 2012
Location: Boise ID
Posts: 36

thanks, chellie and henry...
my 42-40 is a aeolian brand. seems like it is bigger than 42mm. the mount that came with the motor had more widely spaced holes that wouldn't fit the blind nuts on the plane.
I ordered the electrifly mount, it fits the plane, but not the motor. I used it as a guide and drilled out (widened) the mounting holes on the stock mount, and it worked, but when i tried to mount the motor, the heads of the screws were rubbing the motor housing as i was trying to tighten, causing them to cross-thread.
so i pulled it out, and ordered me a turnigy 42-38, it should fit (hopefully)
http://www.hobbyking.com/hobbyking/s...dProduct=30864
also, my servos fit very loosely in the servo mounts, any ideas on how to mount them securely? i was going to cut and glue a small piece of ply on top of the existing mounts with the exact servo size, to prevent it from moving. (servos are turnigy mg90's, mini size.)
and at the risk of sounding stupid, i can go from 3s to 4s pack on my setup and gain more watts and more rpm?
this motor says 403w on 3s and 785 on 4s/
so i can fly tame on the 3s, and then agressively with the 4s?
henry, did you have esc cooling problems? i see you exposed the esc to air on the side of the fuse. i did that on my hellcat, too. should i mod the stick before flying it? i got a HK 60amp esc for it.
thanks for all your help...
my 42-40 is a aeolian brand. seems like it is bigger than 42mm. the mount that came with the motor had more widely spaced holes that wouldn't fit the blind nuts on the plane.
I ordered the electrifly mount, it fits the plane, but not the motor. I used it as a guide and drilled out (widened) the mounting holes on the stock mount, and it worked, but when i tried to mount the motor, the heads of the screws were rubbing the motor housing as i was trying to tighten, causing them to cross-thread.
so i pulled it out, and ordered me a turnigy 42-38, it should fit (hopefully)
http://www.hobbyking.com/hobbyking/s...dProduct=30864
also, my servos fit very loosely in the servo mounts, any ideas on how to mount them securely? i was going to cut and glue a small piece of ply on top of the existing mounts with the exact servo size, to prevent it from moving. (servos are turnigy mg90's, mini size.)
and at the risk of sounding stupid, i can go from 3s to 4s pack on my setup and gain more watts and more rpm?
this motor says 403w on 3s and 785 on 4s/
so i can fly tame on the 3s, and then agressively with the 4s?
henry, did you have esc cooling problems? i see you exposed the esc to air on the side of the fuse. i did that on my hellcat, too. should i mod the stick before flying it? i got a HK 60amp esc for it.
thanks for all your help...
#18
Member
Thread Starter
Join Date: Aug 2012
Location: Boise ID
Posts: 36

so, i glued in some basswood square stock to mount the servos. and going from the stock 4-40 push rods to the .074 kind, a little smaller and lighter... using gp clips on the servo end and gp metal clevises on the working end....
just waiting on the motor, and then she'll be almost ready to fly! (still got to solder the esc and battery connectors)
just waiting on the motor, and then she'll be almost ready to fly! (still got to solder the esc and battery connectors)
#21

Just curious boss.
I have a used electrick stick I bought at a yard sale a while ago and I've been looking into getting it going. Has a couple good dings here and there, and the bottom fuse and landing gear has been mounted to some hot glue gunned balsa.
I have a used electrick stick I bought at a yard sale a while ago and I've been looking into getting it going. Has a couple good dings here and there, and the bottom fuse and landing gear has been mounted to some hot glue gunned balsa.
#22
Member
Thread Starter
Join Date: Aug 2012
Location: Boise ID
Posts: 36

i ended up drilling holes to match my motor mount. used machine screws to mount the motor with no. 10 washers and lock washers to secure to firewall. left blind nuts in place. i did end up getting a turnigy power 32 motor, it is slightly less powerful than the other 42-40 i have. it should work. (900kv, about 740w on 4s, and 370 on 3s) i got the esc ready to go, just need to rig the controls/servos and rx, and she's ready to fly... thanks to all for all your help and advice.