May 28, 2014

Bixler FPV, inventory check

I've since long planned to put an FPV system on my Bixler to start flying FPV with a fixed wing craft. It would be easy to just put camera and transmitter on the plywood FPV platform for the Bixler and be done with it but the machine itself needs some adjustments as well.

Right now the power system consists of the "stock" ESC and a 2836 950Kv motor. The motor is a bad pick for the airplane. It's over sized but too slow. I would either need a bigger prop or a faster motor. I will go with a faster motor to be able to stay with the same prop and get the air speed up a bit.

The stock ESC has rumors of being kind of an asshole when it comes to low voltage cut off in the sense that it cuts the radio system power as well. And we all know what that means. Additionally I'm not too happy about the current wiring mess in the fuselage and I will be putting more stuff into it which means I need to tidy up.

Here's the new stuff that I need.

  • Motor: HobbyKing 2834 1250Kv
  • ESC: Keep the stock one (20A)
  • UBEC: HobbyWing 3A switch-mode
  • 3x2dm 16AWG motor leads
  • FPV Camera mount
  • Vtx: ImmersionRC 600mW
  • FPV Camera: Sony super HAD-II board camera
  • LC filter components: Coil and capacitor
  • JST connectors and 22AWG cables

I intended to start this build already tonight, expecting it to take a few weeks but it seems that all parts are not yet in place. I have most stuff already, LC filter and camera components are ordered and shipped but I need them later anyway. But I need cables right from the start and as usually I have ran out of 16AWG cables.

May 27, 2014

FPV250 body center frame available from HobbyKing

HobbyKing has a new exciting product on their new items page. It's a body frame for the FPV250 that makes the build more like the QAV250 and the Blackout mini H-quad.

This will makes it much easier to mount camera, transmitter and receiver. I'm still missing an adapter piece that makes a CC3D easily mountable on the frame.

Update: The daily:

May 25, 2014

Connector soldering day

I got a few new batteries yesterday and I had to resolder the connectors on them. They always tend to come with the XT60 but I prefer the EC3. While resoldering the batteries, 4 of them, I also took the time to solder up some charging leads that I have been considering for a while.

I made charging leads for JST, EC5 and a barrel connector for the fatshark goggle battery. All this is only to be able to plug stuff into the parallell charging board, which is far more practical than unplugging/plugging into the charger directly.

JST, Barrell connector and EC5 for charging from the EC3 board.

Bruce mentions issues with the motors in the FPV250 ARF

I just noticed Bruce of RCModelReviews commented on the quality of the motors from HobbyKing used in the FPV250 ARF, more specifically the Turnigy Multistar 1704 1900kv. From Bruces point of view they're crap. See for yourself.

May 16, 2014

Fixing the video transmitter

After having crashed into of the trees in my garden with the FPV 250 the antenna connector of the video transmitter started to break off. The onlt thing keeping it together is the soldering on the transmitter PCB which is enough for flying but not enough for crashing.

Damaged transmitter connector

Considering that the video transmitter is one of the more expensive parts on the FPV 250 it's definitely worth the effort of repairing. Or at least attempting.

I started by desoldering the damaged connector. The top soldering was broken loose, the center pin broken off and the bottom ground pins needed desoldering.

Top side with connector removed, the copper surfaces broken off.

Bottom side before desoldering what was left of the connector

Since the top side was badly damaged with the copper surfaces broken off I had to try to make use of the copper available. Since the ground plane surrounds the original surfaces that can be used. First the surface must be uncovered. This is done by filing down the protective coating carefully and cleaning the surface. Be careful not to remove too much of the copper.

When the surface was uncovered I placed a small metal piece to "bridge" the gaps where the connector was previously soldered. The bridge will be soldered on the ground plane surfaces and the new connector will be soldered to the bridge.

Copper surfaces uncovered with metal bridge in place.

Bridge soldered in place

New connector in place, bottom side

Top side of connector soldered to the bridge

Video transmitter on the FPV 250 with a short antenna.

I tried to use a short skew planar antenna instead of the long one. This was mainly to avoid future problems when crashing. This is a cheap antenna from HobbyKing. This could have been a good idea but the antenna performs quite badly. Until I find a good short antenna I'll stick with the ImmersionRC that I've always used before.