Fatshark Predator V2 VTX module replacement

Since the beginning I've been  flying FPV with the Fatshark Predator V2, this FPV goggle is not made any more and can only be found on Ebay for over $200.  These goggles were less than $200 brand new.  The receiver in this model is a single video receiver, this is two year old technology and in today's technological environment is considered too old.  

Today it is all about diversity, no I'm not talking about  people who are different than you, I'm talking about video diversity.  Video diversity is when your video receiver has the ability to switch between two antenna's picking the one with the strongest video signal (this may not be the most accurate explanation of how it works but I'm not an expert and this is how I explain it).  Video diversity means a more reliable video signal and less signal drop outs.  Diversity also allows you to run two types of antennas, an omni-directional for close range and a directional, helical or patch antenna for longer distances.

I purchased from Banggood the Eachine Pro58 as seen at this link: Eachine Pro58.  It is less than half the cost of the top performing diversity modules out there.  I decided to get this module because there is a firmware out there available from a guy in Europe called Achille, the Eachine module has a lot of capability and this firm ware increases the performance of the module by leaps and bounds.  The firmware can be found here: https://achillesfpv.eu/

In order to replace the module in the predator goggles I had to do some significant modifications which I will highlight below.  These mods are not difficult you just need to be competent at soldering.  Hopefully this post will help someone out in the future.

Photo of the predator V2 before disassembly.  I had previously installed the Attitude face plate and removed the eye cups, not a perfect fit but fits none the less.

Another view of the face plate installed on the goggles.  Was a much better fit than the stupid eye cups.

Removed the face plate, now just need to clean off all the hot glue.

Need to clean off the hot glue from the face plate as well.

Goggle cleaned off ready to disassemble.

Face plate cleaned off.

Only two screws holding the top and bottom plate together, these are located on the bottom.  View of the goggles just opened, photo was also used for reference when putting it back together.

View of the stock VTX

I cut all the pins seen in the photo above.  Removed all the black plastic around the pins then used the soldering iron on the bottom side of the board to heat up each pin and push it flush with the board.  I then used needle nose pliers to grab the top of the pin and while holding the board up by the pin, placed the tip of the soldering iron against the side of the pin causing it to heat up, liquefy the solder and with the weight of the board pulling down the pin would come out of the hole.  My only concern working with this board was getting the solder holes too hot causing them to come off the board so I avoided direct heat to the holes as much as possible.

I then soldered wires with servo connectors to each of the pins.  Don't worry about wire color or anything like that, the pins on the main board line up directly with the pins on the module so you don't need to worry about which pin is which, just connect them like this, top on board to top on module, 2nd one down on board to 2nd one down on module going all the way down in order.

I then had to cut both the top and bottom of the case with my dremel and cut off wheel to fit the servo connectors seen in the photo above.  The cut off wheel only melts the plastic but does a good job and after the plastic hardens a few seconds later it can be cleaned off easily.  I then attached the module with double sided tape and hot glue.  So this module is mounted on the outside....is it ideal?  No but it won't fit inside either so I had to make a choice.  You can't really see it any of the photos but the hole for the screw is between the two stock boards when you open it up.  Stuff on the back of the Eachine module makes it to where I couldn't get the pins to even touch the hole to solder them on.  I guess maybe there is a way, I could have looked at it more and messed with it more but I felt that this was the way I wanted to do it.  Another benefit to doing it this way is if I want to change modules again in the future it will be just a matter of unplugging this one and plugging in the new one.

Here is the module fully installed, just lacks a little bit of hot glue also.

I put the face plate back on and hot glued it in place.

Another view of the face plate.  I also had to take a permanent marker and color the glue because I was getting a little bit of light leakage on the top and bottom.

Well, that was it, I hope this helps some one.  I will be flying this weekend with the new module installed so I should be posting my initial thoughts sometime next week.

Thanks for reading, see you next time.

Turnigy 9xr Pro Gimbal Replacement

Well, I went and did it.  After 3d printing some gimbal covers for my transmitter (9xr Pro) I eventually dropped it on the floor and broke a gimbal.  I didn't notice at first that a gimbal was broken.  I found out the hard way.....trying to fly my quadcopter.  Control was so bad I performed a controlled crash ( I lost it ) into a bush, see video here: https://youtu.be/Q5FOA63PeVs

Hobby King used to offer replacement gimbals that would work in this transmitter, however they have been discontinued.  After some research I discovered that with some modifications the stock gimbals from a taranis will work.  This post is about my experience doing the mod and getting everything to work. 

I will post a series of photos that will show the work that was done and include the final product.

This is what the stock taranis gimbal looks like.

This is what the stock 9xr Pro gimbal looks like.  Notice the differences, location of screw holes and elevation of screw holes relative to the face of the gimbal.  This is where the modification will happen.

Stock gimbal still in place Mode 2 Throttle and Yaw gimbal

Stock gimbal still in place Mode 2 Pitch and Roll

The 9xr Pro gimbal screw holes are further apart than the taranis holes, hence the need to modify.  Cut the outer holes off the taranis gimbal on each corner

Grind down the top surface of each corner at the holes that are left.  There is what looks like two layers of plastic, you want to grind down the top layer completely.

This photo shows the top layer ground down to the second layer.  Second layer is hollow so you'll see it when you get to it

Another look at the first layer gone

The screw holes that are left are also too deep for the 9xr Pro screws and the ones that come with the gimbal are unusable so you have to cut some off the bottom of the screw hole or you can try and find longer ones, if you do you can skip to the bottom.  I cut mine even with the horizontal plastic that is between two screw holes on every side of the gimbal.

Here is another look, see the clean untouched plastic between the corners, that's the level you want to cut too.

Now you want to cut some of the screw hole out at about 45 degrees in each corner, don't cut out too much.

Pre-install the two screws near the center of the transmitter, these two are the most difficult to get in, leave enough height to slide the taranis gimbal underneath.

Now install the gimbal by sliding it underneath the two screws you just installed, add the two screws toward the outside of the case.  Once positioned the gimbal will be held in by the 4 screws however some may be halfway on depending how you position it.  This one appears to be completely in the hole which leaves the other side only about half way.  Either way once all the screws are tightened down they will hold and the gimbal will not move.

Photo of another mounting screw.

Photo of opposite side (pre-installed screw), see how the screw only makes use of half of the hole but the screw is still covering plastic holding in the gimbal

Now you will need to remove the wires from the 9xr Pro gimbals that you took out, need to reuse all four JST connectors.

Gimbal fully installed.  Notice colors of the wires on the taranis gimbal does not match up with the wire colors or order of the 9xr Pro gimbals.

Other side, the vertical wire group barely reaches, you'll need to break loose some of the yellow stuff covering the wires so that you can get the green harness where it needs to go also.

When it comes to the wire order, if the colors on your taranis gimbal are the same the order shown in these last two photos should work.

The three pins for the JST connector should read the following with a meter from left to right, 0v, +/- 0.5v, 3v.  If your sticks are reversed you will need to swap two of the wires, which ones I can't tell you it's just a matter of trial and error.  After you connect everything put the cover back on and plug in the battery, don't screw in the cover because if something is wrong you'll need to get back in their.

Turn on the radio, on the main screen you should see a depiction of two gimbals, move the sticks to confirm correct directions.  If all is correct, don't worry if the sticks don't show full movement on the screen.  Now hold down the menu button to bring up the options.  Go to radio set up and perform the calibration.  I recommend performing the calibration with the front chrome looking plastic cover on the front removed because the sticks will hit it in the corners.  Once calibration is complete and sticks move fine you can secure the covers.

You may also need to trim the chrome cover depending on how high the sticks go.  I had to trim two tabs around the opening for both sticks before putting it back on.

Good luck