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Afterburner on Viggen Mod issue.

OGBugsy

Junior Member
#1
I ran into a problem with the afterburner mod. The 70mm EDF setup runs off 4s lipos (3s as well but under powered), and the brushed esc's i can find for lipos, only go up to 3s. The LED's for the afterburner just flash with the 4s instead of gradually getting brighter with 3s.

I tried powering the brushed esc off a seperate castle bec set to 9v output, but it only gets the led's to flash. I have searched for a brushed esc that will handle 4s, but no luck as of yet on finding one.

:confused: Any thoughts on a solution? Thanks in advance!
 

rcflyer729

fpv and rc planes
#3
You can fix the problem with the after burner by getting 12vult power out of the battery balance plug. Just use a multimeter and put one leads on the red wire coming out of the balance plug and the other on each of the black wires until it reads somewhere around 12vults.
 

OGBugsy

Junior Member
#4
You can fix the problem with the after burner by getting 12vult power out of the battery balance plug. Just use a multimeter and put one leads on the red wire coming out of the balance plug and the other on each of the black wires until it reads somewhere around 12vults.
Thanks for the reply.

I am currently using the balance plug with a lipo voltmeter/alarm, but I can totally see your fix working. Thanks! Any way of doing it without plugging in another plug each time? Are there small transformers or step-down relays that are used in rc?

Thanks,
OGBugsy
 

RichB

Senior Member
#9
The only afterburner mod I know about is the one with the butane, so it took me a while to figure out what you were doing.

It seems like you are running a brushed ESC as a dimmer for some LEDs? Pretty cool idea. And I gather that your EDF ESC and your dimmer are running off the same throttle channel. The issue you are running into is that when using a 4s, you have good thrust but you wind up over-volting the LEDS, and when using 3s, your LEDs work fine but you don't have as much thrust as you would like.

I can see three easy solutions:

1. A 12v UBEC feeding the dimmer, which someone already mentioned.
- or -
2. Calibrate your EDF ESC to go full throttle when your throttle signal is only at 75%, then set your radio endpoint to output max 75%
- or -
3. Use a spare channel for the dimmer and mix it to 75% of throttle stick.

I don't recommend tapping into 3 of the 4 cells in the pack, as was suggested. That will throw your battery out of balance.
 

OGBugsy

Junior Member
#10
The only afterburner mod I know about is the one with the butane, so it took me a while to figure out what you were doing.

It seems like you are running a brushed ESC as a dimmer for some LEDs? Pretty cool idea. And I gather that your EDF ESC and your dimmer are running off the same throttle channel. The issue you are running into is that when using a 4s, you have good thrust but you wind up over-volting the LEDS, and when using 3s, your LEDs work fine but you don't have as much thrust as you would like.

I can see three easy solutions:

1. A 12v UBEC feeding the dimmer, which someone already mentioned.
- or -
2. Calibrate your EDF ESC to go full throttle when your throttle signal is only at 75%, then set your radio endpoint to output max 75%
- or -
3. Use a spare channel for the dimmer and mix it to 75% of throttle stick.

I don't recommend tapping into 3 of the 4 cells in the pack, as was suggested. That will throw your battery out of balance.
Spot on with your assessment their sir. I'm hoping it will look awesome at dusk. I took Hawkmans suggestion and bought a 12v ubec. It's on a boat from china as we speak.

I'll give the mixing a shot and see if I can get it working. Much obliged for the great tips. When I get it working i'll post a couple videos

Thanks,
OGBugsy