Upgrading to a servo-driven landing leg set means the legs can be toggled to raise/lower from a spare channel on the receiver, I envision using this for aerial photography where footage is currently obstructed by the crab legs.
I chose the 600-class retractable gear set as I wanted only a single channel sacrificed on the receiver and didn’t want to run two 450-class sets – which is designed for smaller frames – in parallel.
To mount the retractable gear set to the frame I purchased 4 x Shock absorbing CNC aluminum tube clamp (10mm) which will fit the 10mm rails on the underbelly of the Predator 650 frame. A perk of this particular landing gear set is below the servo bar is ideal space to mount a camera gimbal, this be be done without modification.
I’ll update this post when the item arrives 🙂
[5 days later…]
Retractable landing legs arrived and they’re big! I’m thinking the 450-class set would have been fine, but I have not installed them yet so am still confident I made the right choice. Also the 4 additional tube clamps were unnecessary as the frame includes its own set.
The bulkhead that houses the servo’s has holes punched into it to suit a larger frame, they’re too far apart to be usable with the Predator 650 so I’ve drilled my own holes in line with the underbelly rails of the 650-frame.
Additionally since there’s so much space on either side of the bulkhead I’ll move my battery from the underbelly of the frame – was strapped behind the 4-in-1 ESC and FPV camera – up onto the bar and install a 2nd 4500mAh 4S battery to balance the weight out.
Before I shelled out for the dedicated Aircraft Navigation Lamp Set (install guide here) from HobbyKing I wanted to add some basic LED lighting to the motor arms of my X525 build, I still use these LED’s as one displays the Motor Arm status, the other the GPS Lock, that and the dedicated navigation lights don’t talk to Arducopter.
Update: The voltage of the LED strip has to be 5V. Too low, your strip will burn. Too high and it might not turn on (thanks Wei).
1 x LED strip in your preferred colour for GPS Lock (I went for blue, but you could also use yellow)
1 x LED strip in your preferred colour for Motor Arm (I went for red, ala The Danger Zone)
Connecting the LED’s to the APM board
If you went out and bought the 3 LED strip’s mentioned above you can connect the LED servo cable’s directly to the APM board’s analog input’s after a quick change of one of the leads to the JR connector.
We can connect these particular LED strip’s directly to the APM board as the LED’s draw less than the maximum permissible current of the AVR chip on the APM of 40mA per input, the LED strips we’re looking at draw 33mA per input.
Update: The current limit is 40mA per pin or 200mA total. Any higher and you risk damage to the APM (thanks Wei).
By moving the positive lead (red cable) over one spot to occupy the signal line APM can power the LED lights on/off when it chooses, left unchanged the LED strip will be connected to the +5V rail and be always on; which looks cool but is useless.
Using a small sharp knife lift up the tab on the positive lead (aka red cable) of the JR connector that holds the pin in place
Pull on the positive lead while the tab is lifted to remove it from the JR connector
Re-insert the positive lead into the space typically used for the signal line (the next available space) of the JR connector
Make sure the tab is down and the positive lead is secured by giving it a pull
If you’re using the current release of APM then you’re on AC 3.1.5 (Arducopter 3.1.5) and the following will apply, read further for the AC 3.2 changes which will apply when AC 3.2 is officially released.
AC 3.1.5 (today)
A4: AUX led
A6: GPS – will flash with no GPS lock, solid with GPS lock
A7 through A11: Motor LED’s (always on)
AC 3.2 (future)
A4 : Motor LED
A6 : GPS – will flash with no GPS lock, solid with GPS lock
Connect your LiPo battery and power up your APM board, lights on, enjoy night flying! When you’re ready consider upgrading to the Aircraft Navigation Lamp Set (install guide here) mentioned earlier as you can then add real-world lighting sequences to your build.
Turnigy Multistar 2814-800Kv 123 (HobbyKing didn’t stock the 2814-800Kv so I pulled the trigger on the smaller 2214-800Kv, not ideal as the motor mounts don’t all line up but close enough, in hindsight should have waited for the 2814-800Kv)
NTM 28 Carbon Fibre Motor Mount (as above, used the cross mount from this kit to mount the Turnigy motors with holes 16mm & 19mm to the Predator 650 motors mounts with holes 19mm & 25mm, no motor mount screws are provided so used screws scavenged from previous builds to mount the the cross mount to the motor mounts, if you get the 2814-800Kv motors mentioned above you mount directly onto the motor mounts)