Taking the plunge - FPV

[TonyS]

Not sure if anyone's interested in this but I thought it might be of some help to others setting off on the trail of FPV experiences....

 

For Christmas my better half treated me to an FPV kit from firstpersonview.co.uk

 

I think this was prompted by my being spotted looking on the site one day and commenting on how it might be interesting to give it a go... (Still not sure what I've done to deserve such an amazing pressy - or what my wife's done to feel so guilty about...)

 

Anyway, the first things to cover off are:

1) I'm going to mount in an Easystar but my existing Easystar is fully built so I need to buy another one which is unbuilt so I can re-configure the guts of it to take the extra gear and re-arrange the servos etc to balance out the plane as the added weight of the FPV kit will mess with the CG

2) I'm using a Spektrum 2.4 GHz Tx for all my planes which I can't use with the 2.4 GHz FPV transmitter because of interference so I need to buy a 35mHz Tx and Rx (currently bidding on one on eBay so fingers crossed)

3) I want to put a brushless motor into the new Easystar to give it that bit more ooomph at launch given the additional weight. I still want the long flight times and the slow flying so I'm thinking a nice torquey set-up. If you're reading this Timbo and others any help / advice here would be welcome....

4) When I've worked out what motor I'm going to use I need to source a flight battery (My current Easystar runs on a massive 3,700mAh 2S which will be too big I think, given I'm going to split the flight battery and FPV batteries.

5) I need a camera battery however I already have one of these with a JST connector as required - I'll use one of the spares from my Blade CX2 which is a 900mAh 2S - recommended was a 300+ mAh 2S so it should be plenty! 

cont..... 

[TonyS]

I also want to be able to pan/tilt the camera with a headtracker so I ordered the appropriate bits from FPV.

 

My comments on the FPV kit are:

The whole set-up is very well put together. You don't get any instructions as these are all downloadable from the website so that's fine.

There is a bewildering array of bits, bobs and cables in the box (when my wife's finished with the camera I'll take a pic of the box and contents and post it) She's busy putting my old iPhone 3G on eBay to help pay for some of this gear so if anyone's looking for one let me know.

 

 All the equipment looks first rate. I would however suggest, now I've bought it, that anyone remotely handy could save a fair bit of dosh knocking together the pan/tilt mount instead of buying one as it's basically one servo stuck on another with a metal bracket on the top. (£65 from firstpersonview!!).

 

First jobs are:

Order up some of the missing bits. (servo's for the plane), charge up the goggles, weigh the whole kit and caboodle. As I know what the servos will weigh and I can find out what the batteries will weigh I can then determine the AUW which will help when deciding on the motor.

 

 

 

[Biggles' Elder Brother - Moderator]

Mmmmmm! I'll be following your progress with interest Tony

 

BEB

[birdy]

Interesting.

[paul@scc]

Hi Tony.

I have a Mega 16/15/4 in my EZ* which produces more than enough grunt for my FPV kit.

 

[TonyS]

Thanks Paul. Very helpful, I'll look into that.

 

OK. So a few pics.

Firstly, the kit as I received it (including the pan / tilt and headtracking module.

Opening the box...

And all the contents of the three packs (gulp)

Seems daunting however there are a few parts that assemble intuitively such as the goggles, earphones and light shroud...

Shown above with the USB charging lead and the control unit. 

 

[TonyS]

And even I could work out that the antenna screwed onto the back of the Rx

As you can see I've already soldered some 4mm gold connectors onto the power lead for the Rx. I did this to match the connectors on the LiPo that I'm going to use (One of the ones I use in my Panther EDF). As everyone knows the cost of batteries is eye-watering so I'm determined to use batteries I already have..... 

[TonyS]

I charged the goggles - which is done by connecting the USB lead from my computer into the side of the control unit. There's a handy red light that goes out when they're fully charged. It took me around one and a half hours to charge them.

 

The pan / tilt mount is, as I said simply a servo glued to another servo with a bracket on top..

You can see on the inside of the far bracket arm the servo arm which is screwed on from the outside. The bottom servo has a circular servo plate glued to a square of plastic which is then glued to the second servo.

Interestingly, if you read the manual it identifies that this gives you two dimensions of movement i.e. laft / right and up / down. The third axis i.e. corresponding to rolling your head from side to side (as you might instinctively when the plane banks) is missing to reduce complexity and cost. I've been racking my brains to come up with a way of easily building a mount that can cope with all 3 axes but it is tricky.

[TonyS]

I've just plugged all the bits together and switched on and yes, it works.....!!

Initial impressions are that the pic can't be expected to be perfect given that I'm using it in the house where we have WiFi which does interfere. There was some 'rolling line' interference.

The colours aren't great but then it's a very dull day and I have lights on. I'm hoping that this will change when it's out in full sunlight.

My wife put the goggles on and I wandered off around the house with the camera. She had to take them off as she was feeling queasy with the motion. (But then she did once claim to have sea-sickness 20 seconds after stepping onto a canal barge which was moored up to the canal bank!!) 

[TonyS]

I have thought about an On Screen Display (OSD) showing altitude, speed battery life etc but this is another £170 for the 'budget' version and £299 for the high-end Dragon OSD kit. Ouch!

 

Right. Now back to the plane.....

So far as I can see the only bits to fit are the Cam and Tx, battery and pan/tilt set-up.

The cam and pan/tilt mount is the heaviest and this needs to be fixed, according to the destructions, such that it looks slightly down and includes sight of a part of the fuse for orientation purposes, around one third of sky and two thirds of ground for optimum light / exposure.

 

I'm going to mount the whole thing on a ply plate across the top of the cockpit cut-out in place of the existing cockpit canopy. This seems to be the usual practice.

 

Oh, as an aside, I have found a spare brushless motor - It's a Turnigy C3530-1100. This seems way too big for the job but if I could use it it would save me both the money and the wait for parts. Can anyone give me any views on this please? (The recommended prop sizes would be too big for the plane so I'd have to use a smaller prop than recommended) 

[paul@scc]

What 35meg tx are you going for? I would of liked a head tracker, unfortunately it was not possible to use a head tracker with JR equipment.

 

I'm not sure on how a third axis would help you on the tracker. If you are banking left at say a 30 deg angle and then you rolled your head in the same direction the image would be very confusing.

 

I can see a OSD, GPS and a diversity switcher coming next

[TonyS]

Hi Paul,

I'm going for a Futaba T7CP. They seem to be going, second hand, for around £100. I'll then need to buy a decent Rx to go with it.

The head-tracker kit was designed for 'high-end' Futaba sets apparently. 

 

The third axis wouldn't necessarily 'help' but it would allow a completely natural camera movement to replicate what your head's doing. I would have thought this would be far more intuitive and just 'feel' more normal.

More importantly the absence of the roll axis does cause potential 'drift' issues with the tracker. There is a button on the tracking module which you press when you begin flying to zero the pan/tilt to the neutral position. This can 'drift' in flight and you'll need (apparently) to press and re-zero if this happens. Without the roll axis if you move in one axis then roll your head then reverse the initial movement then you don't end up where you began - the head tracker won't know this however so you'll need to re-zero. The solution given is to not roll your head whilst flying which I can imagine isn't easy. (Maybe strap a couple of polystyrene blocks to each side of your neck  ...) 

[paul@scc]

Hi Tony.

I had a Futaba T7 before JR, I was gutted that I got rid of it.

I'm no expert in motors but I think the motor you mentioned above would not be suitable.

It needs to have a kv of around 2000 like this motor. I think my mega is 2200.

 

I've not touched the FPV for months, I even had it up for sale at one time. I think this thread of yours my get me back into the FPV.

 

 

[TonyS]

Hi Paul,

Shame about the Futaba Tx. I suspect that there'll be plenty around as more and more people move over to 2.4GHz and Spektrum sets. I've found a few sets advertised on eBay and elsewhere so I'm holding my max bids at £100 and will wait until I win one or find one at that price. It'll take me a short while until the whole set-up's ready to fly anyway.

 

Glad to provide the inspiration to dust off the FPV stuff.

 

I suspect that you're right about the motor - certainly an inrunner will be easier to fit than the outrunner although the set-up's starting to take shape. Pic to follow. 

[TonyS]

My first thoughts on the set-up of the plane are...

What you can't see is the replacement of the standard servos in the fuse sides below the wing. I've got a pair of slimline servos on order for another project (they were for the flaps on my Gloster EDF   )  but I'm thinking that I could cut them into the tail surfaces for the elevator and rudder. This shifts the weight to the back of the plane to compensate for the extra weight at the front. 

Also by mounting the outrunner back from where the original motor is housed this too will shift weight to the back.

Hopefully I can then use my original chunky 3,700 mAh battery for flight power (the red one!) and position the smaller cam battery forward of the battery velcro'd to the underside of the top of the forward fuselage. 

[Tim Mackey]

Not much clearance for a large prop is there? Pity really, cos I really like big props over little uns. So assuming you are stuck with about 6" diameter, you will be needing a prettty high Kv motor to get the power you want - unfortunately this will come at the expense of noise with the high RPM. Aninrunner will be fine for this Kv, and also easier to fit in what looks like pretty limiting mounting system.

How about something like this from Rob at Giant Cod.

Should be good for about 300 watts or so on a 3s, and at around 12 quid, a lot cheaper than the megas ( although they are lovely motors )

[TonyS]

You're right Timbo.

I'm hoping that if I can fly it like my existing Easy then it'll climb on half throttle and need little to keep it afloat thereafter hence I can keep the noise down.

 

Not sure what you mean by megas....?

 

The Mantis is cheap at £12 it's also quite heavy though at 130g and it means I'llhave to re-think the flight battery from the current option (2S) to something else. The only 3S batteries I have to use are 1,700 mAh. Wonder if this will be enough?

Edited By TonyS on 01/01/2010 20:22:04

[Dusty]

Mega Motor's Tony... expensive but very high quality type! these

[TonyS]

I've now made the ply plate and mounted the pan/tilt camera mount.

When I'm using it I'll fix it to the fuse with a rubber band as it's shown now.

There's a handy slot at the back which allows the wires to feed through.

 

[TonyS]

Wow!

I see what you mean by expensive. £12 plays £63  ....  are they really that much better? 

[Dusty]

Never owned one, only expensive motor I have are HET.. by reviews they good motors!

[Tim Mackey]

I have 2 of them - one is now in my Rippy Spit, and the other is in a yet to be built Alienator.

The older one is a 22 20 3e and was bought years agao at around £85 from memory.

Beautiful, quiet and well built sturdy motor, kevlar bound windings, etc.

Dont think I would buy another purely because these days there are loads to choose from, at verg good VFM -back then it wasnt so.

[Dusty]

But reality is he is flying with a FPV so whilst having pricey gear attatched to a piece of foam why not have a pricey motor and stuff so Tony has reassurance in his gear... I look forward to the test flight, how long we looking at for a review Tony?

[paul@scc]

Tony.

Before glueing my EZ*  together I cut away the foam area that your red lipo is butting up against. This lets the lipo slide far back in the fuse. 

 

In my opinion there is no need to put the servos in a different position.

 

Heres where I put my ESC. I did have it on top.

I like your camera mount, very neat.

[TonyS]

Dusty - you're right I'm sure. Why throw hundreds of pounds up in the air on a rubbishy cheapo motor.....

I'm from Yorkshire, so that probably explains it 

 

I've just ordered a 2200Kv Wasp motor from BRC (£18.99) along with two servo extensions for the servos which are now being mounted at the back. I've also ordered a GWS 6CH RX and a couple of sets of crystals (shouldn't need more as I'll be sat in a field on my lonesome somewhere out in the country). Which just made me remember I won't be on my lonesome exactly as I'll have a buddy which means I need a buddy lead.....  more expense 

Anyway. If it all arrives early next week I could be up and away the following weekend weather and work permitting. 

Actually, I'm thinking.... If I'm sitting down (as recommended) flying the plane and the video cuts out I should theoretically be able to hand the Tx to the chap next to me that's been spotting the plane for me... If I'm out in the country flying a foam plane that should be safe enough shouldn't it...? 

 

PS This isn't an invitation to rekindle the old FPV safety debate folks!!