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Old Dec 05, 2010, 04:48 PM
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Gree's Avatar
Sydney, Australia
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Yep that's right. The go pro isn't even wired to anything at the moment. I'll try moving the camera away from the aerials first to see if it is worthwhile pursuing. I might also try a 7x4 prop to see if I get more push from that.

How Many amps does the 7x4 prop pull on your 2200kv motor Daemon?
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Old Dec 05, 2010, 05:41 PM
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I see.
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Old Dec 05, 2010, 05:45 PM
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It's been a while since I measured it, but I think it was a little under 30 Amps static
and probably a bit lower in the air. I'm usually flying at least a mile above sea level so I
wanted a little bigger prop for more llow speed acceleration better climb rate on my old
Funjet. I don't fly it flat out very often. Just cruising around with a couple
fast bursts, and a couple fast climbs I could still get 15 minute flights with
all the FPV gear on on the FUnjet. I suspect the Skyfun will go longer because it has
more wing area and seems to glide a bit better.

ian
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Old Dec 06, 2010, 05:07 AM
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Great thanks. Yes I want a very good climb rate. I build this for climbing quickly to the clouds. I might try my faster motor for the hell of it after I try fixing the go pro issue. If I can't easily resolve the go pro interference, then I think this will become an SD plane
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Old Dec 07, 2010, 08:45 AM
Flying FPV from the lab.
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well gree, the adrenaline this plane will bring you will still be worth the effort in SD.
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Old Dec 07, 2010, 04:01 PM
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We shall see. First day of my holidays, so I'll make a decision today after I play around with it a little...

I'm kind of leaning towards fast motor, slightly bigger 40C batteries and SD with OSD...

But I do like to change my mind!
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Old Dec 07, 2010, 10:46 PM
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Well I can definitely confirm the Go Pro plays havoc with the Thomas LRS! I tried an experiment of moving the camera away from the aerials by about 15-20 cm and I get a really good range test.

I moved the camera right next to the aerials and got about 3 steps away before it went into failsafe!

Crazy damn camera eh? Looks like I'll try antenna relocation.

I am a bit bummed because I don't have a 2mm prop adapter that I need for my fast motor, and Hobbyking is out of stock! Looks like I'll try a 7x4 on the motor I have for the time being. At least I can get it flying.

I put the watt meter on the stock prop and it was about 240W, so a fair loss of power by having to use the stock prop the other day. Hopefully the 7x4 will give me a good climb rate so I can get to see some clouds!

I now also have my entire Eagle Tree OSD set up, so I will be trying to fit all of that together for the rest of the week. I think I will try to get it flying with the Go Pro first since I went to the trouble of getting the mount built and everything, then see how we go!
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Old Dec 08, 2010, 09:38 AM
Flying FPV from the lab.
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eagerly awaiting results. Video too.
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Old Dec 09, 2010, 12:28 AM
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ARGGHH just spent ages typing a message and the 'token expired' and I lost it all.... sheesh! Here we go again...

I moved my antennas for the 3rd time, right to the back of the plane, and this seems to have greatly improved my range testing issues. I am calling that job done. It meant moving my receiver all the way back next to the speed control, but on range testing running the throttle up and down didn't seem to affect things.

I also spent today configuring, formatting and firmware updating all my new Eagle Tree gear. I had to modify the go pro cable and video tx cable so that I could have both video and audio. Everything is pretty much set up on this side of things (except for me mounting the pitot-tube for my airspeed indicator), and nothing blew up when plugged in...


Tim at http://readymaderc.com was brilliant answering all of my repeated questions with the upmost patience and detail. His level of customer service is the best I have ever experienced anywhere, and I highly recommend his store to everyone - especially electronics luddites like me!


Now on to the next problem...
Now that the go pro issue is sorted, I have found that I don't have very good video. This could be because I am drawing power from the flight battery instead of using a secondary battery (but let's face it if I do that this thing will never fly because of the weight! I'm pushing it already) - or, it could be because of a rather embarrassing incident that happened about a week ago...

I was walking into my 'workshop' with a jaunty step and a healthy swing of the arm. Unfortunately, I was carrying my brand new video tx in the hand of said arm, and at the bottom of the swing where I had the most velocity, the antenna from the tx caught on my pants leg, causing the tx to be flung from my hand in what resembled a spectacular sideways pole vault of olympic proportions. I watched in fascinated horror as the tx passed along its perfect parabolic trajectory, and plopped right into one of our fish bowls, happily bubbling away as it slowly fluttered to the bottom.

I rescued the tx and ran it under the tap for a while to try to flush out any salts, and left it to dry in the sun for a week (indoors of course). When I plugged it in there was not any smoke, but perhaps this may have had a bearing on the poor video?

The signal is very weak, and if touched it disappears altogether. Nothing is ever bloody easy is it...
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Old Dec 09, 2010, 10:08 PM
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I do think that the motor you are using is not going to have anough power at all there.

I think you will need a motor with at least 500watts for it to fly. It's going to do a prety quick landing after launch I think. This thing is going to need power and lots of it.

I did have the ET in my FW190 and it was just ok. No way could I do any sort of acro with all the weight. It was using a 300watt motor and all I could do was fly it making sure I had the wings level most of the time.

You really need to work out the power to weight ratio and wing area to get it going right. I just ton't think you are going to have enough power in that poor little motor to fly decent and enjoy fpv with the go pro on there.

5c

B
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Old Dec 09, 2010, 11:26 PM
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Video woes continue

I WILL FLY THIS THING!

Dammit.

OK so the video issue. I am pretty stumped. I have a hunch but I need some input from everyone to nut this out...

OK so all the Eagle Tree gear is hooked up correctly and seems to be functioning.

I have my 400mW video tx (the one that went for a swim) hooked up to the flight battery for power, and I have a single wire going to the video out on the OSD, and another single wire going to the audio out on the OSD (neither have a ground - I am hoping the video needs one and this will solve the problem!).

When everything is powered up, the video picture is awful! Check out the video below. No matter how far away from the plane I move the tx it makes no difference to the picture. If I touch the tx the picture gets worse. Hmmmm, ok I thought perhaps the power coming from the flight battery is doing this. So I hooked it up to a different battery - same thing.

http://vimeo.com/17664500


OK, so maybe the video tx has been damaged from the water - so I used a different tx that I know to be in excellent condition. The video was a bit better, but still bad enough to prevent flying.

OK, so I thought I'd bypass the entire OSD system and plane, and hook up the go pro right to the tx. I made an adapter to hook up the single video wire from the go pro into the tx - nothing, no picture at all...


SOOOO - I am starting to think (or perhaps hope!) that the video running to the video tx needs to be earthed? The video coming from the go pro is earthed going into the OSD, and then the video tx has an earth going to the power source, but the video going to the tx has no earth. Does this make a difference? Does it need one?

It's the only thing I can think of, since even my proven tx had poor video.



I really hope someone can offer some suggestion here because I have no idea how to fix this...
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Old Dec 09, 2010, 11:36 PM
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Quote:
Originally Posted by Mr_B View Post
I do think that the motor you are using is not going to have anough power at all there.

I think you will need a motor with at least 500watts for it to fly. It's going to do a prety quick landing after launch I think. This thing is going to need power and lots of it.

I did have the ET in my FW190 and it was just ok. No way could I do any sort of acro with all the weight. It was using a 300watt motor and all I could do was fly it making sure I had the wings level most of the time.

You really need to work out the power to weight ratio and wing area to get it going right. I just ton't think you are going to have enough power in that poor little motor to fly decent and enjoy fpv with the go pro on there.

5c

B
Thanks for the 5c Mr B! I have actually flown the plane with this motor and an unsuitable prop. IT was a bit tricky to launch, and not the fastest thing in the sky one up there, but I could loop and stooge around pretty good. It even glided forever, and landed at a pretty decent speed. Of course it is heavier now!

However I am very open to suggestions for a motor and prop combo that you think will do the job!

I have a much better motor (this one http://www.hobbycity.com/hobbyking/s...idProduct=8480), but need to get a 2mm prop adapter for it. The thing with that is that it will swing a 4.75x4.75 prop, so it may not have acceleration. And by the look of the stats, still not enough grunt?

As I said, this is all an experiment, so I am going to give it my best shot first before I revert to something more sensible... But no matter what motor I have I can't fly it until this damn video is sorted!
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Old Dec 09, 2010, 11:49 PM
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How about this one?




Or would something like this be better? http://www.hobbycity.com/hobbyking/s...dProduct=11173

This motor is rated to 650W http://www.hobbycity.com/hobbyking/s...idProduct=8138
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Old Dec 10, 2010, 12:28 AM
Flying Monkey
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Australia, NSW, Sydney
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Quote:
Originally Posted by Gree View Post
How about this one?



NIcE , I would be inclined to use that big one as a wind genny or use it on a GoKart . Sry haven't got the Tube link for it but they exist.

I would go for mabey http://www.hobbycity.com/hobbyking/s...idProduct=2100 with a 9x6 folding prop on it.

http://www.hobbycity.com/hobbyking/store/uh_viewItem.asp?idProduct=8138 looks ok but you would be going into 4cell territory with that I think.

Anyone with some ideas on Motor prop Combo for a 1.4Kg Fast flyer ?

BTW Make sure you use a ground from the signals, It needs to be able to go ina and out with the grounds so there is no issues. (Common ground between everything connected) You will run into variations in ground causing issues if the ground points are floating.

B
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Old Dec 10, 2010, 01:11 AM
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Lakewood, Colorado
Joined Aug 2002
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Quote:
Originally Posted by Gree View Post
I have my 400mW video tx (the one that went for a swim) hooked up to the flight battery for power, and I have a single wire going to the video out on the OSD, and another single wire going to the audio out on the OSD (neither have a ground - I am hoping the video needs one and this will solve the problem!).
There *must* be a common ground between camera, OSD and video Tx.
Your grounds should come from your power supplies to a single common point
and then branch out to each component like octopus arms, rather than
running ground from component to component to component (creates ground loops).

For an small span overweight plane you don't want a super high rpm motor spinning a small prop.
The prop will be stalled when you throw the plane and it'll be even harder to launch.
2000-2200kV with a big prop will launch and climb better.

ian
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