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The EXTRA 300 EXT Build Thread

Enterprise

Enterprise

150cc
I do reduce power on the cut off and set it to 3.0V (under load) so that I know when it done as the reduced power should be enough to hobble home. It will probably hit that limit doing some crazy trick like extended crankshafts, so I know the battery is getting low under load. I set up voltage telemetry in all my electrics so I have not hit LVC in a few years.
 
AKfreak

AKfreak

150cc
So at 3V it cuts your power, does it pulse it? I always run on a timer, and use those silly Lipo alarms set to 3.6v. Also I am in development of my secret weapon against Gassers that keep me grounded. More on that later ;)
 
AKfreak

AKfreak

150cc
Hey guys I have a question. I have all of the servos installed in to the plane. I am using the ESC's BEC (5A) temaproly to set up the linkages and center the servos. A weird things happens when I hook up the two elevator servos at the same time as the rudder servo. The receiver an AR-7000 glitches and starts blinking and the servos act all crazy. Example is I move the elevator only, but the rudder moves in random directions spasticlly back and forth, then it will stop and I will be completely locked pout for 5 -10 seconds, then it comes back. Its strange, I can run the rudder no problem, I can even run the rudder and a single elevator servo, but when I ad the third servo that is when this thing goes apeChit.


I thought it might be current draw, but these servos are not under load, and they should only be drawing .2 amps each. The ESC bec if good for 5amps. So what do you guys think? I havent seen this before in any of my builds.

BTW I just ordered 2 Glacier 1100mAh 2S 6.6V LiFe packs, but I dont see how this is going to change this problem.
 
gyro

gyro

GSN Contributor
Sounds like your dropping the voltage to the rx below minimum when you move the controls. Hook up a watt meter between the ESC wire and rx to confirm.
 
Enterprise

Enterprise

150cc
Using a BEC on the bench for extended times can be a issue as well as they are designed to get cooling air. I have a couple of cheap AA deals I have from my glow days I use for bench setup or a LiFE pack.

I am having all sort of trevails with my 550 heli with some expensive BECs, and to solve the issue I use a cheap capacitor. This issue should go away once you have your LiFE packs.

When the ESC hits LVC it pulls the power back to 50% or so. Enough to get home.

In my telemetry I use somewhere between 3.3 and 3.6V under load to give me a warning so I usually land long before this time. Weak packs will set this off sooner and sometimes I just fly to the timer as I know they have the capacity, just not the C rating.
 
AKfreak

AKfreak

150cc
I was using a Thunder Power 5000mah 70C 6S pack attached to a Castle Ice 50 just to use the 5Amp BEC to center the servos so I could setup linkages. 1 or two servos was fine, three servos bad. I cant believe my Gecko 120 HV is DOA. I opened the box, soldered on the ends, hooked it to the programmer and got nothing. I tried it in the plane, nothing. What a pain the neck to have to deal with ZTW directly for replacement. I am just going to buy a new one and when it comes back from China I will have a spare I guess.

I got my 85 Gecko from Altitude Hobbies and it works great. The 120 Gecko I got elsewhere not so, man! I tried to buy a new one from Altitude, but they are out of stock. Anyone know if there is a ZTW factory rep stateside? I was hoping to have the Extra ready to go for St George, but its not looking so good. Anyone got a Spare 120HV laying around they want to lend me till I get this DOA esc sorted :) Ahhhh... the joys of ignorance.
 
3dNater

3dNater

3DRCF Regional Ambassador
Dude! Im sorry about your bad luck! I would help if I could but I dont have what you need.
 
Enterprise

Enterprise

150cc
The only HV ESC I know of with a BEC is the Scorpion Commander. There is a battery port on the programmer for this very purpose. You could also hook that castle ESC that has a BEC up this port just to get power to the system. If this is your first foray into HV ESCs, that is a very easy thing to get confused on.
 
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