Taking the plunge - FPV

[TonyS]

Should have mentioned that I put the prop on the same way as on my old Easystar so it may be that I've been flying with that the wrong way around since I got it!!

[Clive Matthews]

I've checked all your figures and they add up. Just to confirm it, tacho the prop. You should be getting around 20000 rpm.

 

Two possibilities come to mind. You are close, but not exceeding the current limits of motor and ESC. It does sound like ESC overload. It could also be the dreaded 35Mhz v brushless motor glitch.  

 

If possible, I would try another ESC first, perhaps a 35 - 40 amp one if anyone near you can lend one. 

[Colin Naylar]

Just browsing this thread Tony and thought I'd throw in my twopennerth - I have had this symptom in the past with my old easystar and it was down to an old wornout battery - a Nimh in my case. I presume the ESC was cutting out due to low voltage. A new battery cured the problem and I didn't look any further into it.

[TonyS]

Thanks Clive / Colin,

I was hoping that you wouldn't say try a new ESC as it's buried in the fuselage.. and before anyone says anything, I know that I was counselled not to bury it but......

As for the battery I hope it's not that as I just bought it !!

The other thing to note is that I can run it no problem on the ground. It might be the 35mHz thing...? I did put  the ESC below the back of the wing near the motor and the Rx is in the nose...? The antenna does however run under the esc  but I wouldn't have thought that would have been a big problem.....but then, what do i know - I put the prop on the wrong way around... 

 

PS Don't have a tacho. 

[Colin Naylar]

The only 'glitch' that I have experienced with 35mhz is when the ESC interferes with the electronics in general and causes all the servos to start twitching and jittering. This effectively results in much reduced range. I have cured this every time by fitting a ferrite ring onto the ESC lead that runs to the throttle channel of the reciever. A normal range check with lowered aerial easily shows this up though. 

[Clive Matthews]

If you can borrow an ESC, might it be possible to tape it to the outside just to prove whether it's that or not.

 

I'm not certain that you had put the prop on the wrong way round. I always thought that the writing on the prop went in the direction of travel, so I'm no wiser than you! Are pusher props different though?

Edited By Clive Matthews on 04/03/2010 20:28:07

[TonyS]

Colin,

For the price of a ferrite ring it can't hurt so I've ordered some.

It may well be that as the servos can be a bit twitchy but only on the pan/tilt - the elevator and rudder seem fine.

I have to say I'm glad I've got 2.4 in my other planes! 

[Tim Mackey]

Posted by TonyS on 04/03/2010 18:44:35:

Well, from the FRONT of the model the prop spins anti-clockwise but the numbers are facing to REAR of the plane?!

Swapped it over and now I'm getting 20-21A and 220W @ WOT.

 

AUW is 1 lb 14.4 oz or 870 ish g 

 

Well then it WAS on backwards, and you should notice a big difference in thrust now !

220 Watts makes that over 100 watts per lb which is more than ample. If speed is lacking, then try a higher pitch, if thrust /acceleration is lacking then try larger diameter ( if room permits )

Edited By Timbo - Administrator on 04/03/2010 23:47:37

[Tim Mackey]

Posted by Clive Matthews on 04/03/2010 20:21:52:

If you can borrow an ESC, might it be possible to tape it to the outside just to prove whether it's that or not.

 

I'm not certain that you had put the prop on the wrong way round. I always thought that the writing on the prop went in the direction of travel, so I'm no wiser than you! Are pusher props different though?

Edited By Clive Matthews on 04/03/2010 20:28:07

 

Its not a pusher prop - these are redundant in electric models as one simply reverses the direction of rotation to suit. The writing should be "facing forward" as with any prop on any model, and roatation is anticlock as viewed from front....again just like any model - it matters not that the prop is at the back.... thrust is thrust whether pulling or pushing

[Sheldon Holy]

Hmm. I just have to butt in here, it's drawing 220 watts, not giving 220 watts.

Sheldon

[TonyS]

Hi Sheldon, 

Not to split hairs but I said getting 220W meaning that was the reading I was getting but anyway.....

TodayI started putting the field box together. You really don't have any choice about this due to the sheer number of wires etc etc.

So far I have wired up the two 2.4Ghz receivers. These both run AV cables back to the Diversity switcher and both require a 12V supply. One has a patch antenna connected which will be mounted on a camera tripod next to the box. (Can't find my tripod so may have to beg/borrow/scrounge or even buy one tomorrow).

The Diversity switcher then links through to the DV recorder (thankfully this runs off an internal battery) and to the goggles (the goggles require pre-charging via USB).

The Diversity switcher also requires a 12V supply.

Pics to follow..... 

 

[TonyS]

The field box..

The RH receiver has the patch antenna (at the moment just laid on the top) the LH has the standard antenna. All the wiring passes straight into the box via some new holes...

and the receivers are stuck on with velcro.

Inside the box we have the 12V battery and the Diversity switcher plus the recorder..

There's also plenty of room to store the goggles, tripod, chargers, remotes etc etc.

Tomorrow I'll wire up all the 12V supplies - I'm debating whether or not to wire it all via a master switch set into the box lid - that way I'll know that I've switched the supply off to everything when I'm done - I picked up some snazzy dash switches with green or red lights in from Halfords which should do the job. 

 

[TonyS]

At long last.

Maiden flight this morning. Weather bright but quite breezy.

I flew the plane and roped my good lady into wearing the goggles (I don't think she quite got the head-tracker thing at all and claimed the motion made her quite queasy - could be my flying - she says the same when I drive her about in the car 

Anyway, the plane performed fantastically - what a change the brushless motor makes to the Easystar (when you have the prop on the right way round!!) - fabulous.

Sorry for the shaky video. It took me two hours to find a programme that could convert the format into one recognisable by iMovie. I've only edited it by removing the long period at the end when no signal was being received - not sure what went wrong there......

You get occasional glimpses of the sprouts, the farm and the two of us stood in the mud. Still, little steps.. 

You Tube - maiden FPV flight. 

[Simon Dale - Firstpersonview.co.uk]

Hi Tony,

 

I'm glad to hear that you've made your first flight.

 

The quality of your video is terrible though... I'd put that recording device in the bin!

 

All the best

 

Simon

[Simon Dale - Firstpersonview.co.uk]

Also, if you plan to fly by FPV you'll need to have something of the plane in shot (the nose usually) as an attitude reference.

 

I'd recommend having 2/3rds ground and 1/3rd sky in your shot to get the best performance from your camera.

 

These things, and many more tips, are in our manual and/ or our guidelines here:  http://www.firstpersonview.co.uk/myfiles/file/FlightKitManual.pdf and
http://www.firstpersonview.co.uk/myfiles/file/FPVsafety.pdf 

 

All the best

 

Simon

Edited By Simon Dale - Firstpersonview.co.uk on 07/03/2010 13:54:09

[TonyS]

Thanks Simon,

I did set the camera to see the nose but I guess my missus was looking upwards all the time  

The recording is awful. Not sure whether it's all the recorder's fault. The image in the goggles isn't terrific (may need some adjustment)  plus the camera that came with the recorder gives me good video playback. Also, the camera stopped transmitting 1 min 20 into the flight so no signal at all was getting back to either the goggles or the recorder - no idea what went on there. 

Will try again before I think of investing in any more kit. Total cost to date including plane batteries etc £1,150 so I was keen not to pay £250 for the recommended DVR recorder when I could find one for £150. I may end up regretting the decision but I hope not.

Thanks for the tips though.

Tony 

[Simon Dale - Firstpersonview.co.uk]

Hi Tony,

 

The main problems with the video are framerate and compression artefects (you can clearly see a gradient on the sky for instance) - both of these are digital compression effects.  The FPV equipment is all analogue and is not responsible for any of  that.

 

The actual light handling (between the dark ground and bright sky) looks pretty damn good to me and it looks like the colours might have been quite good on the original video.

 

Why the feed stopped after 1m 20secs requires some investigation - was it that the recorder stopped recording after that time or the camera stopped transmitting?  In the former case it could be a full memory card or something?  In the latter case - what voltage was your battery at?  Does the camera work now? Loose connection perhaps?

 

All the best

 

Simon

[TonyS]

So what you're saying is I should bin my recorder and buy, presumably the recommended one. So, taking out the DVR recorder I bought and adding in the recommended Archos (with recording snap on) would add £320 plus postage taking the whole set-up to £1,480 ish...

Not for the faint hearted. Time to start selling stuff on eBay.... Anyone interested in a lightly used kidney?

[Simon Dale - Firstpersonview.co.uk]

Hi Tony,

 

I'd stick the one you have on eBay (or return it as not fit for purpose - you have I think 14 days to return it for any reason under the distance selling act) and look out for either a camcorder with AV input or a used/ refurbished Archos 5.

 

Amazon have the 120GB Archos 5 for £160 here: 

 

That looks like a great deal to me, you can't get them used on eBay for that price.

 

All the best

 

Simon (from FirstPersonView.co.uk)

 

Edited By Timbo - Administrator on 13/03/2010 16:39:37

[Tim Mackey]

Oh I dont think Tony will be allowed to sell his used kidney on Ebay - and as for returning it as unfit for purpose....well who should he return it to?

[TonyS]

Good point Timbo.

Actually I think I'd be done under the misdescriptions Act anyway as it's far from lightly used...

 

Simon, 

DVR recorder on it's way back tomorrow by recorded delivery.

Off to find something suitable.

The Archos thingy seems to me to be way more than I want or need - wifi / web browser / news service / media store etc etc. If I want all that I have an iPhone or a laptop - I sure as heck don't want to sit in a field doing it anyway. I just want a top quality digital recorder....

Time for a hunt around...

 

PS

Simon,

Just as a pointer, if you want to post links into your comment, use the link facility (chain icon in the menu bar above) otherwise the posts run under the ads and you can't read them...Copy the link into the box where it says URL then type something like " Here" into the description... 

 

PPS You may like to go in and edit your post so that it can be read properly...

 

Edited By TonyS on 07/03/2010 17:40:40

Edited By TonyS on 07/03/2010 17:41:48

[Frank Skilbeck]

What about one of these http://www.maplin.co.uk/Module.aspx?ModuleNo=339259&C=Froogle&U=339259&T=Module but you might need the docking station to be able to record to it.

 

If you could find one of the older Archos 560's that would probably be ideal, I have one and have a small adaptor which plugs into it and it can then record at upto 640 x 480 pixels and quality is pretty good.

 

One on ebay here and travel adaptor here

 

They stopped making it because it didn't compete with the IPod.....

 

Cowon also made a similar unit which you could record to.

[Simon Dale - Firstpersonview.co.uk]

That 405 looks good.  I have an AV500 here which has served us well for FPV recording for 3+ years.

[TonyS]

I bought an Archos 5 in the end with a Snap on - from Amazon.

With the kit all together, with a little more weight in the nose of the plane and a ferrite ring on the output from the ESC I figured this weekend was the time to go for it once again.

This time I took the kit up to the local club - LHC at Oxhill.

The usual crowd were there plus a half a dozen others.

I'd no end of interest int he set up and a ready volunteer to fly the plane whilst I played around with the video / goggles.

To be honest it didn't go well.

There is still a problem with the motor which Rob, the pilot, suggested felt like interference.

Throughout the flight the motor was unreliable.

The video through the goggles was terrible with boat loads of interference at best and a complete black-out for most of the flight.

The Archos only recorded a second of the flight right at the start.

When the video packed in completely and permanently we decided to bring the plane in and all control was suddenly lost, at which point it headed into a neighbouring paddock.

The fuselage is repairable, as is the pan/tilt mount.

The main issue is that I just don't know what the problem was with the motor or the interference with the video.

The club is pretty remote so I wouldn't have thought we'd have a problem with wi-fi etc.

There were others (one or two) flying on 2.4 which may well be the explanation.

Anyway, I'm getting pretty frustrated now. I know that it is possible to get decent FPV video - there's evidence on the web. The fact that there isn't a huge amount suggests to me that this isn't yet for enthusiastic amateurs like me but for a dedicated few with lots of technical knowledge and an unlimited budget.

I'm not one to be defeated so I'll plod on. My next plan is to re-design the plane (it needs a re-build anyway). I'm going to move the ESC and mount it externally above the wings - this should cool it better and move it about as far as I possibly can from the antenna.

I'm going to re-do all the soldered joints in case that was the problem. If that doesn't fix it then I have to say I'm all out of ideas....... 

Hey-ho! 

[TonyS]

PS Sorry that you can't read the full posting

If any Mods want to edit Simon Dale's posting above to replace

the offending pasted web-link then that will be helpful.

Thanks

T