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Finally, first FPV flight.

PostPosted: Fri Jan 20, 2012 7:52 am
by Sid Sideslip
Well, I finally got my act together and had my first FPV flight. I'm using a bareback HobbyKing/Foxtech 200mw 5.8GHz system, though with the standard antennas atm, as I'm waiting for the correct right angle RP SMA connectors for my clover leaf (the Rx skew planar is done, but I didn't use it). I have the $17 HobbyKing PAL camera plus their pan/tilt head and that wide angle replacement lens that Paul uses, mounted in a foam block and held down by elastic bands where the canopy goes on the AXN (see photos). The Rx is mounted high on a telescopic mast made from an old photographic light stand, which I picked up for a dollar or so at the tip shop, plus I added an extra length for greater height. FatShark base goggles.

As this was just going to be a quick test of the system, I didn't have the Remzibi OSD mounted as yet, figuring that I'd just cruise around the clubhouse and not go very far.

Now, I wear glasses and wouldn't you know it, nobody was at the club to act as a launcher and spotter. Plus, the sodding sea breeze was blowing a near gale. But what the heck, I've hardly flown in a calm day since I got back into RC planes, so I figured go for it, as the axn is a breeze in er, a breeze.

So with nobody to launch for me and spot, I launched wearing spectacles, got up high and then popped my glasses in a pocket and pulled down the FatSharks.

First eyes were adapted to the glare, so I couldn't see a damn thing for a bit, as the video was too dark. By which time I was over the highway and disoriented. Did a banked turn and found the club house, but kept losing the signal in the turns (which I expected). Problem was, the wind was blowing a gale up there and it was damn hard to fly. I REALLY missed a sense of where the throttle was (I wish the 9x had a ratchet throttle, not a friction one).

Without the OSD I had the same beginners problem as Paul (BMSWEB) did on his first flight; without depth perception it's hard to judge height and speed (no sound makes that much, much worse) and although I'm used to flying full scale, it was still a bit hairy.

Anyway, I wasn't really comfortable staying within the club's boundaries (the neighbouring farms don't take kindly to models over their horses) so I decided to cut it short and land. Which is when I lost it. A combination of nasty gusts, lost signal in the banks and inattention to throttle, meant that I stalled it coming round when the wind dropped for a second and I nearly nosed in. I popped the nose down and added power, but by then it was just too late and I belly flopped in the outer somewhere, facing the wind.

Which is where it gets kinda funny. The axn was upright and I could still see through the camera. There was a clump of grass in front of the nose obscuring things (bugger!) but I could still pan (thank gods for a pan and tilt mount!) So I swivelled the camera around, but couldn't really see where I was. Anyway, I trudged off to where I thought it was...but the grass is really long away from the strip and so it's easy to miss your model.

No bloody sign of the axn though. Up down, up down. Nope.

Back to the Rx mast and off with the glasses and on with the goggles. Then back on with the glasses again. Mmm. Through the FatSharks I could see two trees to the left off the clump of grass and a hill behind, with trees at the top and when I panned right, two different trees nearby. Didn't look right for where I thought it was. Off with the specs and on with the goggles again. I drew a mental picture of what I could see...walked away from the mast and scanned the horizon.

Then I spotted it...I had searched in completely the wrong direction. The model was behind me parallel to the runway, not out past the strip as I'd thought. All was OK, no damage done. But I am definitely going to use both the Remzibi OSD and the circularly polarised antennas before I go out again...on a much calmer day. Oh, and a spotter too. ;-)

Btw, I had an absolute ball. :-)



Re: Finally, first FPV flight.

PostPosted: Fri Jan 20, 2012 12:48 pm
by rogueqd
Yay! Well done Sid. Great to see you finally got there. :) Sounds like quite an adventure for your first flight. I'm glad you found her in one piece.

You may have thought of some of this already but here's a few things I worked out...
Get some headphones and plug them in to the goggles. You can hear the motor, and the wind noise, and it helps a lot.
It does take a while to get used to how close the ground is, land with a bit of throttle so you don't stall. Skidding on the grass is better than stalling a meter up and nose diving. For my first few flights I flew the plane overhead and took my goggles off then landed the old way.
You can launch the plane with your goggles on. It's another thing that seems really weird the first time but is actually quite easy and then your eyes never have to adjust.

Congrats again. Don't want too long for your second flight. :)

Oh, and last thing, I just realized that your CP antenna doesn't have to be upright, lol. You'll probably lose a little bit of range with it on it's side but it should work just fine for a few hundred meters at least. Enough to keep you flying until you get the adapter.

Re: Finally, first FPV flight.

PostPosted: Fri Jan 20, 2012 5:23 pm
by WildWill
That sounds like so much fun, congrats on your first flight!

Hopefully I won't be too far behind. :D

Re: Finally, first FPV flight.

PostPosted: Sat Jan 21, 2012 4:18 am
by RCModelReviews
Yeah, I went through a few batteries today flying FPV -- bloody marvelous fun.

I just *love* bareback FPV -- no OSD, no RTL, no altitude hold -- just the camera and the video link.

Now I'm landing within 1m of the desired point every time and practicing my ultra-low flying for chasing the gokarts around the track next door.

Just need a better camera. The HK unit didn't like the heat today (yay - we had a real summer's day) and kept going monochrome instead of color.

Re: Finally, first FPV flight.

PostPosted: Sat Jan 21, 2012 8:11 am
by Sid Sideslip
rogueqd wrote:Yay! Well done Sid. Great to see you finally got there. :)

Thanks mate. Yeah it was a blast. I'm glad that I waited to get comfortable flying again though, but it was still a bit silly to maiden FPV in those winds. My main problem was that I just didn't trust the signal and the snow in turns was really unsettling. Still, the couple of passes I did over the strip downwind flat out were just amazing. Can't wait to get out with the skew planar and cloverleaf fitted. Btw, I just used a straight connector for the cloverleaf and bent the coax up and held it with some balsa and hot glue. It should work OK until I get a right-angle rp sma connector.

I've also spent today velcro mounting the OSD on the side of the fuse, just ahead of the motor Two patches near the ends of the OSD, which leaves a nice gap under the OSD to cool the board where I've cut away the heatshrink, as per Paul's excellent video..thanks Paul!) with the GPS near the tail, to get as far away from the VTx as possible and also to counterbalance the camera and pan/tilt servos. So many wires to fit to length and solder. But when I switched it all on I got no picture. Panic! Then I realised I'd held the set home button down too long and switched to NTSC...duh.

Weather permitting I'll fly again tomorrow and film using the keychain camera. Must get a cheap video camera to record from the base Rx too.

To infinity and beyond! :lol:

Re: Finally, first FPV flight.

PostPosted: Sat Jan 21, 2012 10:19 am
by Keith
Congrats Sid, glad to here you enjoyed it (mostly)...

I think the same as you about the throttle stick with the friction control. I got mine real tight but it still feels funny after all ratchet type ones...

The last time I had the back off I thought about getting the hacksaw and cutting notches in it and then putting a kink in the pressure plate..

Re: Finally, first FPV flight.

PostPosted: Sat Jan 21, 2012 11:32 pm
by chrisjunkie
Well I too spent ages flying FPV this morning. By myself too which was a little naughty but was practicing my landing approaches and have them down to a fine art. Land at my feet almost every time - flaperons are great if I'm coming from a height, just not so good close to the ground as you loose a bit of control.

Went for a good 20 mins or so. Interesting to note though, as I was flying around I started getting colourful lines on the screen. Thought it wasn't too good and bought it down for a landing. By the time I was on the ground (watching the plane itself) the screen had gone grey. Turns out my battery was dead flat. Put 1490 into a 1600 pack! Just thought I'd mention it in case anyone without an OSD is flying with their HK camera and Tx on the same battery as the plane and experiences the same symptoms.

Was also given an old sky satellite dish this morning. Going to make a 5.8Ghz biquad and mount it where the old Sky Balun is. Waiting for your DIY tracker to be uploaded Bruce so I can use this!!!!


Re: Finally, first FPV flight.

PostPosted: Sun Jan 22, 2012 4:56 am
by RCModelReviews
Yeah, I'm trying to find an old satellite dish -- as soon as you decide you want one they all disappear -- damn!

Re: Finally, first FPV flight.

PostPosted: Sun Jan 22, 2012 7:18 am
by chrisjunkie
Or they cost an arm and a leg! Not great when you want your hobby to be cheap (thank goodness for some of these Turnigy products!! :-)

I'm thinking of making this: and feeding it into the middle of the dish. I just fear that the beam width of the dish will be too small and it will forever be hunting for the plane? Unless your DIY tracker is hugely accurate Bruce ;)

On the note of trackers, do we need to know the lat/long of the base station to be able to calculate where the plane is?

Re: Finally, first FPV flight.

PostPosted: Sun Jan 22, 2012 5:56 pm
by RCModelReviews
The same thing can be had "readly made" from China for $10 or so.