05-08-2009, 11:41 PM
Hi kev
Heres some info that might help, as you will see i love customizing and building just as much as flying, i guess its the fun of building something yourself and then seeing it actually come together hopefully and achieve what you wanted it to, FLY.
A lot of :geek: info to look at but i guess you need to know it if you want to get things working right.
I'm still learning so much all the time and making heaps of mistakes in the process.
With the A-10 i actually swapped out the EDF's and customized installed new EDF's which i did a spec thrust test that produced a 800grams thrust per unit even when customized to 55mm EDF'S so it would fit in the A-10 nacelles.
The Stock thrust was only 380 grams thrust each unit the stock motors were only 3200kv.
64mm diameter impeller fan - weight: 73g/2.575oz
Volts(V) ... Current(A) ....... Thrust(g/oz) ...... Power(W) ...... MOTOR
11.1 ........ 39 .................. 850/29.983 ........ 432 ....... VMH300XL5250KV
link below
http://cgi.ebay.com/VMD64H300XL-5250KV-B...9004r13855
But I found that now they make a 55mm EDF with the 5250kv, though i notice the thrust was less not sure if there the same
motor as the 64mm EDF i bought, but this would be an easier way to go than what i had to do. As i had to custom fit motor,fixing to the 55 EDF's i bought separately and then balance, and cost me more.
link below
http://www.fmhobbies.com/servlet/the-116...5mm/Detail
Kev Keep in mind when looking at Motors the Amps, as weight will become an issue with battery and esc size in determining the right ratio and thrust you will need.
The motors that I'm running are drawing a lot of amps spec reads 39 amps actual clamp test 36 amps each but having two Edfs producing 1600grams of thrust solves my issue with the overall weight of plane with battery.
Steve who i met on line while i was building my SS2 who has been down the field mentioned rule of thumb 100 Watts per 500 GRAMS of Weight to get Airborne only not high performance Flying and this isn't including wing span. I use this rule also now to help me work out the overall setup.
Eg My A-10 Setup .... Weight .... Amps constant run not burst .... Voltage not peak
......................... 940 grams .... 25 amps .......................... 10.5 volts ............. 25amps x 10.5 volts = 262.5 Watts
262.5 watts times two Edfs = 525 Watts
I needed min 200 watts to get airborne at 940 grams therefore stock motors would have just get me in
the airborne at 700 grams thrust and weight I'm at.
I use the figure 2.3 times what ever watts as a guide to work out approx thrust actual test i use the scales and power them up and the pressure of air flow out of the EDF's hitting the scales will give you a guide of thrust it produces in grams.
Heres some info that might help, as you will see i love customizing and building just as much as flying, i guess its the fun of building something yourself and then seeing it actually come together hopefully and achieve what you wanted it to, FLY.
A lot of :geek: info to look at but i guess you need to know it if you want to get things working right.
I'm still learning so much all the time and making heaps of mistakes in the process.
With the A-10 i actually swapped out the EDF's and customized installed new EDF's which i did a spec thrust test that produced a 800grams thrust per unit even when customized to 55mm EDF'S so it would fit in the A-10 nacelles.
The Stock thrust was only 380 grams thrust each unit the stock motors were only 3200kv.
64mm diameter impeller fan - weight: 73g/2.575oz
Volts(V) ... Current(A) ....... Thrust(g/oz) ...... Power(W) ...... MOTOR
11.1 ........ 39 .................. 850/29.983 ........ 432 ....... VMH300XL5250KV
link below
http://cgi.ebay.com/VMD64H300XL-5250KV-B...9004r13855
But I found that now they make a 55mm EDF with the 5250kv, though i notice the thrust was less not sure if there the same
motor as the 64mm EDF i bought, but this would be an easier way to go than what i had to do. As i had to custom fit motor,fixing to the 55 EDF's i bought separately and then balance, and cost me more.
link below
http://www.fmhobbies.com/servlet/the-116...5mm/Detail
Kev Keep in mind when looking at Motors the Amps, as weight will become an issue with battery and esc size in determining the right ratio and thrust you will need.
The motors that I'm running are drawing a lot of amps spec reads 39 amps actual clamp test 36 amps each but having two Edfs producing 1600grams of thrust solves my issue with the overall weight of plane with battery.
Steve who i met on line while i was building my SS2 who has been down the field mentioned rule of thumb 100 Watts per 500 GRAMS of Weight to get Airborne only not high performance Flying and this isn't including wing span. I use this rule also now to help me work out the overall setup.
Eg My A-10 Setup .... Weight .... Amps constant run not burst .... Voltage not peak
......................... 940 grams .... 25 amps .......................... 10.5 volts ............. 25amps x 10.5 volts = 262.5 Watts
262.5 watts times two Edfs = 525 Watts
I needed min 200 watts to get airborne at 940 grams therefore stock motors would have just get me in
the airborne at 700 grams thrust and weight I'm at.
I use the figure 2.3 times what ever watts as a guide to work out approx thrust actual test i use the scales and power them up and the pressure of air flow out of the EDF's hitting the scales will give you a guide of thrust it produces in grams.
What Do You Mean Theres a Throttle Curve ?, Its Either all the way up or all the way down
