Coyote`s X8

[Coyote]

Hi guys, I had many lengthy conversations with a few X8 pilots last night over various setups and the logical conclusion was to go with the other motor.

The motor is an OS



Old configuration

Scorpion 1100Kv 
Best performance was  566 watts @ 47 amps with 2.4kg of thrust

New configuration

OS 750Kv
Best performance 806 watts @ 48 amps with 3.4kg of thrust

So over 1kg more thrust 200 watts which is a lot ! Burning just 1 amps more for the extra gain at WOT means its going to be a much more efficient plane now
         

[Coyote]

I have just been finalizing the layout for the electronics. So far this is how I have it :



The top left is the Turnigy 5 amp Bec :

I have removed the Bec from the APM power module after finding it was 433 noisy, not good enough so out it came. Now the jumper has been fitted the low noise Turnigy Bec which are very good now will power the APM inputs, outputs, sensors, MinimOSd and servos.

Below is a KK power distribution board :

Here the 5 lipo leads come in and get common-ed up. This is a much better solution than soldering bunches of wires up together and is a much neater job.

Below that is the APM current sensor :

I have stripped the noisy Bec daughter board off the power module for as low a noise floor as I can get, I is also only good for 2.5 amps max so I would need an additional Bec anyway and having this just introduces more potential failure points that are unneeded.

Center is the APM 2.5 Autopilot :

I am running Arduplane 2.75 firmware with the APM 2.5, external Mag, GPS, UHF Telemerty. I am experimenting with a Dronecell 3G telemetry link that Hase has sent up for me to play with as well so that telemetry range and occupying channels very close to my UHF control can be avoided.

The right base board top left is the external Magnetometer :

Curiously has never been used with the APM. When I received the APM the pads looked like they had been separated, but after checking the APM with the Mag disconnected, it still showed the Mag working fine, turns out the pads still had a tiny connection so the external one was getting ignored all along :)

The APM GPS with battery backup sits next to that.

Below left is the MinimOSD :

With the MinimOSD I have removed the diode that allows the 12v from the video side to power one half of the board. Again like the other regulators from APM they are noisy on 433. Going for very long range now thi is unacceptable, but messy having the 12v away from the plugs, removing the diode lets me still use the 12v pins as passthroughs, but no noise. I also joined the Analogue and Digital sides of the boards so that the Turnigy Bec also powers the MinimOSD with its very clean power. I have added a 3.3uf capacitor to the signal line for the OSD so it has DC decoupling also.

Then to the right is the TeleflyOSD with on board GPS for the telemetry for my MyFlyDream antenna tracker. Again, no noisy regulator, its powered again from the Turnigy Bec`s clean low noise power. It has its own GPS sensor so is a stand alone unit and will not conflict or interfere with the APM`s working.

Not being mounted on the bases but picture is the APM airspeed sensor and the Rangelink receiver

[Brucey]

Have you got more details about the mod to the minimosd?

[Coyote]

Hi Brucey, sorry I missed this reply. The 3.3uf capacitor mod of removing the diode to kill the 12v side bud ?

[Coyote]

Paintwork is now done :)



The bottom of the wings is drying, just a simple black segment pattern for ease of seeing

[Brucey]

The diode removal mate

[Coyote]

I`ll do you a two for one :)

The battery monitor mod and the mod I did as well

[Brucey]

Thanks. So by removing that diode, you don't need to power that side of the board from the 12v video feed.

[Coyote]

It wont power the regulator, so you join the analogue and digital pads on the rear so the 5v from the APM powers both sides of the board

[Brucey]

Ah, got ya. Thanks

[chris-s]

What's that battery monitor mod for when you are already using a current/volt sensor connected to the APM? Does it allow you to monitor a second battery eg flight controller pack? Is that part of minimosd-extra?

Finally, what's the capacitor mod?

Oh, and it's looking great.

Chris

[Coyote]

The battery monitor mod is for when you are running a separate 12v video lipo for the FPV side. The APM only monitors the flight lipo`s condition. Yes MinimOSD extra supports the feature.

The capacitor mod it to have a 3.3uf capacitor in the signal line from the APM to the MinimOSD, it physically separates the DC from passing down the signal line.

[Coyote]

Starting to get the parts mounted to the base plates so everything fits. It soon became apparent that with the APM gear going in I was going to have to fit a lot more into the same space as before.

I started making the plates :



Then quickly realized some different thinking was needed to make dead space available so everything would fit.



Tarot motor mounts fitted on spacers to locate equipment higher up.

[Brucey]

Looking great. Nice and neat

[Coyote]

Boards starting to get populated with the bits now.



I simply added Tarot short spacers to the KK power board, no reason other than it looks nice :)



Mag is now up away from the main board for better accuracy. The adjustable PSU is above the APM 2.5 which will be set to 9v to feed the WDR camera, the Lawmate Vtx



Much more happened here. On the right hand board there is now :

MinimOSD
APM GPS
Telefly OSD with GPS