Announcing the retirement of my Bixler...

lobstermash

Propaganda machine
Mentor
And the beginning of active FPV service for my FPV Raptor.

My Bixler has had an adventurous career with me. I bought it around Christmas time last year and was immediately impressed with how well it thermaled. I intended to get it set up nice and to be my first FPV plane. However a mate, just getting into RC planes, desperately wanted to buy it off me after putting his own in a tree. As a replacement, I bought an eHawk 1500 - fpv plans were on hold.

However a couple of weeks later, the Bixler got stuck up the top of a tree again! It spent 2 weeks up there, through rain, wind and sun, and we finally got it down on a cold, rainy, windy night after hitting it with pine cones, cricket balls and large sticks. The motor and ESC were dead, and there were little dents and scratches and a few cracks we'd caused. My mate told me I could have it.

After a couple of hours of work, I had it looking and flying nice again, with a bigger motor and a chunky ESC. I set to work getting it ready to FPV while doubling it up as my slope soarer (too rocky on our slopes for the eHawk).

Thanks to its early hard life, it's always looked like it's done it hard. I bought a FPV Raptor a few months ago, but recently realised it was the replacement for the Bixler, rather than another option. The Bixler is going to another friend who didn't have much success with his first plane (cub) and gave up. The Bixler should be a good alternative for him, and he doesn't have to worry about scuffing it up!

Anyhow, I'll start posting some pics of my Raptor on here soon. I'm loving all the extra space, sleek design and serious feeling size. I've cut out a hole for the camera to poke through the black plastic cover, which holds the camera and canopy in place, lets enough air in to cool the camera and keeps it looking sleek. I've mounted the vtx on the moulded platform out the back and the gps unit will sit on top of the left wing.
 

lobstermash

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I'm not sure about the vtx location. Anyone else stuck something behind their prop like this before? If testing shows it's not a good idea, I'll change it over to a 5.8 system.
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lobstermash

Propaganda machine
Mentor
Could make the plane pitch up due to the force of the prop stream hitting the antenna.

I thought the same, but is there a difference between having that same drag afore or aft the motor? Perhaps less punch from the motor if the air isn't getting past it quick enough...?
 

earthsciteach

Moderator
Moderator
I would say, yes there is a difference. Is the difference enough to amount to anything? I don't know. One way to find out!
 

lobstermash

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One more modification to my setup... My SpiroNET antennas arrived this evening, so I'll be testing them out tomorrow. Swap out the 900Mhz for 5.8Ghz.

Also trying a new location. It's an old space tracking station. Not the Apollo one, but the replacement for it at Orroral, which has also been replaced by Tidbinbilla. Orroral sits in a valley, and was set up as a self-sufficient station in a location picked for its isolation from rf interference from Canberra. It's both beautiful and practical, as there are concrete slabs all over the place, with potential landing strips no matter the wind and stunning mountains and rock formations in every direction. Looking forward to a hopefully very still day tomorrow. The only downside is the flies...
 

lobstermash

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Mentor
Well, Orroral has been done. First up I maidened the Starmax Cub - what an amazing plane... Next I maidened the Ryan, which is a dream to fly. Then the wind came up.

That didn't put me off from getting the Raptor going. I screwed the SpiroNETs into the tx and goggles, chucked it in the air until it was about 50m up and pulled down the goggles. The first thing I noticed was that I was getting diagonal lines in the video. The picture was clear on the ground and cleared up when the throttle was off - vibration through the airframe. The prop is nicely balanced, but obviously I need some dampening on/around the camera.

I pushed the plane out to 1km and started to get the odd beep from the FrSky tx. The video was also breaking up a bit, so I decided to turn around. I was glad I did as it started beeping even more, then settled down as I faced myself.

I'm thinking I have plenty more tweaking to do to optimise the range on the 2.4 and 5.8 gear, but I wasn't all that impressed with it considering I went over 1.5km with my crappy homemade antennas on my Bixler a couple of weeks ago. Anyhoo, I brought it in and went to stick my camera on there, but realised I had a female power connector on both the battery and camera. Oops.

Just for the sake of being thorough, I put my antennas on and flew out. I only got about 800m before the video started cutting in and out, so I guess the SpiroNETs aren't as bad as I thought they might be...

In short I've got plenty of work to do on the Raptor. I'm keen to give the 900Mhz and LRS systems a go now.
 

colorex

Rotor Riot!
Mentor
I'm thinking I have plenty more tweaking to do to optimise the range on the 2.4 and 5.8 gear, but I wasn't all that impressed with it considering I went over 1.5km with my crappy homemade antennas on my Bixler a couple of weeks ago. Anyhoo, I brought it in and went to stick my camera on there, but realised I had a female power connector on both the battery and camera. Oops.

If I understand correctly you got farther with your own antenna than with the SpiroNET ones? Are they worth the $40 they cost?
 

lobstermash

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Well, yes and no. I got further with an optimised setup (as in location of tx, control rx and seemingly internal components) on the Bixler, also on a different day (very similar weather though) and different location. I think my problem yesterday was that the setup needs work. It all seems OK on the ground, but I should be able to at least double the range (my antennas got about 800m, SpiroNETs got 1km) with some tweaking. I'm not convinced that they're worth the $40 they cost - Bluebeams are a better antenna by far, and a precisely made home job (if you have the equipment) would easily be as good. The SpiroNETs sacrifice a bit of range for durability and ease of manufacture (they're flat rather than round, and are stamped out rather than being bent into shape). I have to say that making your own 5.8Ghz antennas is a painful experience, and requires dextrous fingers and quick soldering. I got my SpiroNETs for $31 (for some reason they went through for that rather than the $34.89 list price). To me, worth it.

I'm thinking perhaps the rx antennas under the plane (the reduction in control range from the Bixler was very obvious), the ESC mounted in front of the motor pod and out of the canopy, changing a switching UBEC (though filtered) for an old-fashioned one (not as efficient, but doesn't create interference) and getting the vtx antenna up a bit higher off the fuse. However I might skip these things and try the 900Mhz/433Mhz combo, where I don't have to worry about obscuring the antennas.
 

colorex

Rotor Riot!
Mentor
Ok, if you're doubting it then I'll try my own hand at making one... There is a possibility I will get my hands on a 5.8GHz FPV set in a couple of months... Fingers crossed!
 

lobstermash

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Sweet! Yeah, there's no harm in giving it a go making one yourself. I made mine from the stock antennas, copper wire from tv coax core, solder and a little hot glue. It was fiddly (and a bit frustrating at times), but not difficult.
 

lobstermash

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Mentor
I didn't remove the connectors. The stock antennas have a length of coax, and the active part is the exposed core or some light wire (like 28-30AWG) soldered to the core. Often there's a metal collar around the coax, which is aluminium, but has a copper or brass cap that is soldered to the shielding. For my 900Mhz antennas I used the cap to solder to, however I just checked my 5.8s and I cut them off.

The beauty of using the original antenna is that the connector is correct straight up. Just the antenna may be a little shorter than planned.