Arcfyre

Elite member
When I built my sea duck (a twin) I wired it so that I could power each ESC off of it's own battery OR use a power Y harness to run both ESCs off the same battery.

So now I either fly it off of one 2200 mAh 3S or I charge my two 1500 mAh 3Ses and essentially have 3000 mAh of flight time.
 

ElectriSean

Eternal Student
Mentor
The only problem with a master switch is that it has to be rated for all the current you plan to pull or it will just burn up, probably when you're in the air ;) For safety, all of my fixed wing models use a 2 stage throttle cut on the transmitter. If I absolutely had to kill all power before returning to the pits I would just run the XT60 connectors out the fuse somewhere.
 

Hai-Lee

Old and Bold RC PILOT
If you do not use the motor kill switch you could fit a small flight battery and BEC, (just for the Rx and servos) and use a brushed ESC on a Rx channel to disconnect the motor flight batteries whilst in the pits.

You would need a suitably rated relay or relays and you would need to set the throttle to minimum when you enable the flight motors so that the ESCs will initialize properly.

Just another retro thought!

Have fun!
 
Somewhere in the Flite Test site is a battery calculator, and a hint column about batteries, flight time, and motor power. Hard for me to find. Not sure where and what to type to pull them up.
 

Headbang

Master member
For 4 motors I would just make up 1 4 way harness. Cheap and simple, less points of failure. Disconnect the power lead on all but 1 esc to the reciever. Running 2 batteries parallel is better then 1. Reasons I say that are, you can draw twice the amps, and if one dies you can still land. Assuming C pack motors, 5000mAh would allow for about 7 to 10min flights. To juice it all up go 4s and prop down.

But I might do Sean's solution just for kicks and I have the hardware laying around. And you have to follow the advise of someone who looks like Sean.
 
I was thinking of Sean's plan only because... (Deep intake) FT Guinea Pig & same size Sky-Truck I have. Next build, C-130 Herc similar in size, with 4 motors. So, FT Power Pack C twice, change up the props to 3 blade 10 X 5's. The Pack C is rated suggested max of a 3S 5500 mAh single Lipo. So... dual 3S 5500 mAh Lipo's? The Power Hub is only $7! Using the XT-60 connectors to the motors and to the batteries, safe bet. Build reverse Y-harness from PH to batteries with MPS. I can't say enough about wanting that Master Power Switch. I can find one and easily install it with XT-60 connectors. Okay, easy-peasy install under left wing root, ON to the rear.
This bird is planned to be a demonstration bird for SAR (Search And Rescue) operations. Three cams, FPV, Belly wide angle search, Cargo monitor. With an OSD into the FPV once you find them, the GPS can mark where your target is. Next, as a cargo plane, me bird can deliver parachute drop supplies to the sight to assist in survival until ground forces can arrive and/or evacuation is on scene. Shooting for 5+ lbs. load.
Upgrade will be UHF long range systems.
I know i can build a bird that in the end costs less than the top grade Quads used locally, and with carrying capacity be dime for dime a better stable usable SAR platform.
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Headbang

Master member
Cheap solution for a safety switch would be a jumpered xt90 connector on the neg. Has to be in to arm. With 4 motors you will have 80amps possible at full throttle. Xt60 could potentially heat up and melt. EC5 would work as well. On that note, same applies to a single battery.
 
Cheap solution for a safety switch would be a jumpered xt90 connector on the neg. Has to be in to arm. With 4 motors you will have 80amps possible at full throttle. Xt60 could potentially heat up and melt. EC5 would work as well. On that note, same applies to a single battery.
Sound cool, but my one... fear is a jumper could be hit by something and... Oops! No power! I do love the XT-90 idea for the main battery hookups. Over build, under use. I can get Master Power Switches about half the size of a 9 gram servo that can handle the amps. 240v @ 500 amps. I need to look that Power Hub over for input capacity. Hmm.
 

Headbang

Master member
When I said jumper. I ment you solder a jumper on 1 connector which you use as a key to plug into another connector.

Btw. Kudos for even doing the project!
 
This has been in my mind since... years ago still building balsa and heat shrink skin material came out. Finally RC tech has caught up to my expectations.
I've heard so many people sing the praises of large commercial quads. Sadly in my mind they are an expensive high res camera platform. And the way they fly uses up a lot of power compared to a fixed wing. The ones that could carry emergency supplies into action... you just multiplied your cost by five. A major portion of cost is the on board and control system computers and software. As my Dad would say, "Push the button stupid" flying. Nothing beats a seasoned pilot, and a good set of eyes any day.
Let's compare. $20 or less of DTFB. Basic flight gear, $300, and that's high I'd say. UHF albeit your upping your game into Long Range Flight, possibly now your scratching $1,000 total including control station. Dual 3 camera systems so that one person can monitor Day/Low Light/Thermal cameras in the belly, the other for the pilot as Cockpit, Belly, Cargo Monitor. 6 channel minimum system, 4 flight, 1 cargo door, 1 load release.
Flying pattern as standard protocol, spot the lost. Mark GPS location by OSD system. Drop first emergency pack, water, small handheld beacon/walkie-talkie, LED visual spotting aid. Possibly a few Space Blankets, First Aid Kit, and high protein snacks. Now, in most situations that plane just gave those people a 75% boost to their survival. In two passes.
What would you give to have that kind of system available in your area, forests, mountains, beaches, anywhere?
 

Headbang

Master member
The concept is awesome. Sounds like a job for a scratch built new design with a 6ft wing that can be collapsed in to a pelican case. Designed to drop a canister with smoke or audio beacon. I did a lot of bush search and rescue 20yrs ago. I can think of several cases it would have helped the ground search. And a few cases where it was still a days hike after a heli spotted them. Just a lighter, flare, and space blankets would have made all the difference at -30C
 

ElectriSean

Eternal Student
Mentor
If/when you decide to go with a long range RC system, check out Crossfire, it's an amazing system. I've gone over 5km without losing any RSSI/link quality at 25mW output (It will go to 250mW as needed).
 
The concept is awesome. Sounds like a job for a scratch built new design with a 6ft wing that can be collapsed in to a pelican case. Designed to drop a canister with smoke or audio beacon. I did a lot of bush search and rescue 20yrs ago. I can think of several cases it would have helped the ground search. And a few cases where it was still a days hike after a heli spotted them. Just a lighter, flare, and space blankets would have made all the difference at -30C
I was thinking either a cleaner version of my Sky-Van, or a Herc-Redo.