sparky4lawndart

My Feedback: (10)

oh lords of the EDF screamers... I just bought a JTL BAE Hawk complete with TamJet 90mm EDF and air up retracts with air brakes and I have no idea what this thing should be running on... It was a project plane at the LHS and the customer apparently lost interest... built straight and the plane is clean and the motor is wired really nicely.

My problem is I can't find details about the plane or the motor... is it okay to run 2 4S 5KMah packs.. does it need 10S or 12S... how do I find out. To pull the EDF to see which motor and ESC I'd have to break the exhaust tube and was hoping for a little cheat help. If it helps, the fan/motor combo is new and cost over $800. The plane is supposed to be around $600 (not sure). all the servos are digital JR's

any help is much appreciated!

redbiscuits

My Feedback: (6)

You will need to find out what KV motor you have, and what your max rpm your fan will handle, that will tell you how many cells you can run safely. High power setups are expensive, so it's best to know before you go throwing money at batteries/esc, and hoping for the best.

Here some helpful guides that I have used in the past.
http://www.fanjetsusa.com/Electic_Setup_Guidelines.html

http://www.ecalc.ch/fancalc.htm?neumotors&lang=en

Example #1, if you have a 1500KV motor and you want to run 8S, take the total voltage (x) the KV
3.7x8=29.6V
29.6vx1500=44,400 rpm

Example #2
Your fan is rated at 50,000 rpm and you have a 1500KV motor
50,000/1500=33.3V
This would be adding one more cell to achieve higher rpm. Although, it's better to leave some headroom, as the fan will unload in the air.

Good Luck.

sparky4lawndart

My Feedback: (10)

so I cheated... I called Tam at TamJet and he explained that it's a 10S setup and will run at 3000KV. I tried out an 8S setup and got 2200KV. It's a JetTeng BAE Hawk... it's for sale on RCU now...

redbiscuits

My Feedback: (6)

I think you probably mean 3000 watts. That should be a screamer on 10S. Here is my CMP L-39. It's pulling 3200 watts on an 8S set-up.

https://www.youtube.com/watch?v=GhVHumn9Pb4

sparky4lawndart

My Feedback: (10)

ooops.. 3,000,000 volts... that'll fly! you need a bolt of lightning to fly this plane! lol

thanks for the correction... 3000 watts