Predator Camera Drone build.

[Andy G.]

Hi fellow forum members...

Been following the forum for quite a while now, and have made the odd few postings onto threads but thought maybe a few of you just may be interested in my current build project??

PREDATOR CAMERA DRONE.

The model is certainly not ' True Scale ' but certainly near enough to 'outline' scale that it should be recognised. Also, the model will be a Hybrid compromise of the best bits of 2 marks of predator.. The underslung tail empanage has been ommitted as, a/ too small to be effective and b/ too vulnerable.

The camera turret is also much enlarged over scale in order to fit the Mobius camera into it. The camera turret is designed to pan but not tilt.

I started the project around the beginning of January, by drawing up the plans etc from 3 view drawings etc and getting them printed up to build size.

Construction started early February and has continued sporadically, I have been '' forced'' into a complete new build glider ( Tony Van's Red Eagle ) to replace my previous glider whose wings folded after a long and hazordous career and also a rebuild of my hack flyer following a radio glitch.. Coupled with home and family commitments the build has come on quite quickly IMO.

Anyway.. enough waffle; going to poat a pic or two to gauge the interest level..

O.K, That's what the full size looks like and that's the colour scheme I'm going for.. More interesting than the low viz army schemes..

Basic fuselage formers and base with triangular corner reinforcement

Firewall and motor.. Motor is low Kv 600 watt, and will be running in normal rotation, rather than 'Pushing'.. The 'Natty' cage mounting is not strictly essential, but I rather liked the style of it ..

. That's probably enough for a first post, if there's any interest I'll carry on..

Andy. G.

[Chris Bott - Moderator]

Lots of interest I'm sure Andy, keep it coming

[Gary Manuel]

If there was ever a model ideally suited to FPV, this must be it

[Biggles' Elder Brother - Moderator]

A very interesting choice of prototype - following with interest.

BEB

[Simon Chaddock]

Andy

Very nice but by omitting the under fin and with a much enlarged camera turret is there not a danger that the lateral stability may become critical and comprise it as a camera ship?

The original is not exactly blessed with lots of fin area given its big nose!

[Andy G.]

Pleased to see that there's interest already! And thanks for the encouraging comments..

Simon...... I'm no aerodynamics expert by any stretch of the imagination, and the large camera turret affecting lateral stability hadn't ocurred to me. I have actually drawn the vertical empenage on the original plans and made it, then decided that it was very vulnerable in a slightly nose high landing or even take off. I guess it could be shortened and fitted if there is a problem. As you will see as the thread progresses though, the model is slab sided and has a big dummy jet pod at the rear, so hopefully this may well help to counteract the lack of fin.

The model build is well ahead of the blog, in fact the build element is virtually complete and the fuselage painted so I will be able to post regularly on this and make it look like I'm the world's fastest builder!

Here's a few more pictures to keep things going..

Basic fuselage sides and bottom with doublers added to wing/undercarriage bay area and to V tail mounting area.

Formers going in.

Block parts in rough form before shaping. The small one will be mounted just behind the bulbous nose area to provide a cooling air intake for the ESC and battery bay. The large one is the dummy jet pod, which has an internal air duct to provide cooling to the motor.

The same two parts nearing completion.

Trial fit of the two parts onto the basic fuselage structure. At this point they are just 'plopped' in place on a spare piece of 1/8" balsa sheet to check how they look. The nose has been blocked in and rough shaped too in this pic.and some internal cross bracing added to stiffen things up.

The more astute of you may just notice how the state of tidyness of my work bench slowly decreases throughout the build sequence.. It's still very tidy at this point!!

[Tony Bennett]

looks interesting young sir.

i will enjoy watching your progress.

[adrian lawrence 1]

Looks good, following here too.

[Martian]

love the look of the predator I will be following with interest

[Andrew Price 2]

Me too Martian. Looking good already Andy.

[Colin Leighfield]

Very interesting project. Your bench is immaculate. Mine continues to be a pig-sty, but I'm happy.

[Andy G.]

Good Morning...

Thanks for the positive comments so far, it's very encouraging that others find my efforts interesting..

Colin... My bench is NOT normally that tidy, I had a big ;guilt trip' before i started the photo shoot for the build and spent an hour or so tidying up! I'm posting a pic taken this morning to show the normal state of it!!

A messy bench is a happy bench! LOL

Simon......... Attaching a couple of pics to show the rudder size, as you can see it's fairly small, so I'm hoping I won't need to fit it; the plane is tail heavy enough as it is, the less i fit that end means the less ballast the other end and my build weight is creeping up uncomfortably already.

Fin and rudder assembly.

As I said earlier, In order to fit the Mobius camera I needed to enlarge the turret size well over scale, and decided to make it flat bottomed rather than domed, mainly for simplicity's sake. I take Omega 3 oil capsules to combat joint pain in my thumbs and as luck would have it, the tub they come in was the perfect size to squeeze the Mobius into. I moistened and preformed 1/32" balsa over the tub and left for a few days, then stuck the balsa directly onto the tub with UHU POR. Fitted ply bearing plates to the bottom end ( which will of course be the top when it's installed) to take the mounting rod, and soft block into the cut off top end to give support and shape to what is now the bottom end.. Confused?? Hopefully the pics make it clear..

Laminating the 1/32" sheet onto the tablet bottle.

Lamination complete and awaiting sealing and sanding..

Having made the turret, the turret mounting was the next bit to be tackled. Photos show just how many parts this 'simple' bit needed and how they all went together..

Turret loose fitted to check general fit etc.

Mock up shot to show turret and 'pods' in place.

Lunch is rapidly approaching, so I'll cut this post here and post some more later this afternoon..

Thanks to all that are following, Any comments, critiscisms or what ever are very welcome..

Andy G.

[Colin Leighfield]

I feel much better now Andy. My wife always says I'm a scruff and I try my hardest to live up to her expectations in every way that I can. Your continuing support will be appreciated.

Most real life drones seem to use rotary engines, so to make yours sound really authentic you need to go on ebay and find an OS Wankel engine, there's a few still around.

It's looking very good, you're bound to attract some attention with it!

[Andy G.]

Well, lunch duly over and done with, and another hour done at the workbench, so back to posting.

First pic is a frontal view of the turret with the Mobius camera alongside. It took quite a while to build up the courage to attack the front of the turret with a Dremel and cut off wheel to make the camera opening.. Wasn't quite sure just how the plastic/balsa laminate structure would take to having a large chunk cut out.. It actually went pretty well, just one very small piece of balsa coming away, which was easily stuck back into place.

Camera opening rough cut with Dremel, awaiting final 'fettling' with sanding stick.

Turrret trial fitted into nose.

Drive system for turret. This shares the same compartment as the steerable nose leg, the servo for which will go at the opposite ( front) end of the bay. The original drawing and idea for the nose wheel was a much more scale like affair, sloping forwards like the full size unit. It looked fine in principle on paper, but when it actually came to considering how to build it, it looked increasingly over complicated and more importantly very flimsy. So for the sake of practicality I swapped it for a standard set up, and relocated it to the nose bay. Pic below shows the original idea, which was to construct the leg from 2 pieces of piano wire inside an aluminium tube, with a steerable 'plate' at the bottom end turned via pull/pull system from a servo mounted at an angle inside the fuselage. My club flies from a grass strip and I doubt whether this set up would even have seen out the first taxi let alone a landing..

Sorry..The pic isn't very clear, it's a screen grab from the original CAD dwg saved as a Jpeg and seems to have got very pixelated, but hopefully you can get the idea of how it was intended to work.

More later.

Andy G.

[Martian]

all good fun so far and ingenious

[Andy G.]

Another day dawns, household duties done and spare time again, so here's another post..

One of the V tails under construction. 1/32" ply inner sheet, framed both sides with square balsa section, the sheeted with 1/32" balsa. Pretty light and stiff, although now I wish I had cut bigger lightening holes.

Both tail units after sheeting and shaping, plus the rear cowl and servo / radio gear mounting tray.

A few outside shots next, showing the basic fuselage assembly up on it's undercarriage to get a general view of how it 'sits' and looks. Funny how they look a whole lot bigger in the flesh than they do when you draw them up!

The photos don't show the 2 engineer's squares and the stanley knife tucked inside the nose bay to stop her dragging her tail on the ground!

The finish of all parts has been several coats of Poly-C onto the bare wood, followed by Heavyweight tissue, applied with more Poly-C, then a couple of more coats to seal and finish it. My first experience with this product, which a couple of my friends had tried and not liked. However I personally found it easy to use and gives a good finish with easy clean up.. I'm sold on it now!.. I experimented using the tissue wet and using it dry, seems to be no real benefit to wetting it, so 90% of this model was done dry. One thing I did find out though was you need a really soft brush to apply it, especially over tissue, and too much 'working' of it can cause the top surface of the tissue to rag up quite badly. I used a cheapish 1" decorating brush from B&Q ( other diy stores are available).

Andy G.

[Andy G.]

Moving swiftly on..... :0

Wing build next.. Each wing is 36" , plus an extra 3" of wing root, giving a total of 78" total span. Quite a large span but with that high aspect ratio they don't actually give a massive wing area.

The construction is .. 1/32" sheet skinning top and bottom with 1/8" ribs and a full depth spar, false TE and LE spars used as well. As with the rest of the model, the wings are tissued and Poly-C'd . Attachemt of wings via carbon rod into tube and a 5 mm Bullet connector which acts as an incidence pin and a fastener too.

Colin..... Note the bench is returning to it's usual untidy state..

 

Wing root, square section tube is for servo lead.

 

Edited By Andy G. on 15/08/2014 16:41:34

[Andy G.]

Had to 'split' this post as the next few pics I wanted to post weren't in the album when i was writing it up, and it seems that adding them from another window doesn't refresh the current posting album.. I live and learn!..

So, heres a few shots of the 'beast' outside on the path with the wings on, at this point, the incidence pins hadn't been fitted so the wings are just slid on and 'splooged' into place with masking tape underneath them, so if the seem droopy or gappy that's why..

Roped my '' Beautiful Assistant'' in for this shot to add some scale to the model.. Instructions as follows.. stand still, smile, hold it still and .. Don't let the wing drop off! managed to almost perfection, but don't let her know I've posted this online, she hates her pic being taken..:P

[Dave Hopkin]

Looking good sir...... but don't even think about a maiden anywhere near Cardiff in early September!!!!!!

[Stevo]

Could you ask your assistant how she manages to stand on the wall of the house?

[Andy G.]

Posted by Stevo on 15/08/2014 17:50:26:

Could you ask your assistant how she manages to stand on the wall of the house?

She is Female.. need I say more, in fact dare I say more! Good job she doesn't read this forum..

Dave... I read the Cardiff 'No Fly Zone' stuff on here earlier, but I'm a long way from Cardiff and nothing of strategic interest near me fortunately..

[john stones 1 - Moderator]

You will end up in bother Andy, if someone don't report you to Special Branch for suspicious behaviour your good lady will catch you out

John

[Andy G.]

Darn that wind, blowing up a real bad one here, definately no flying today, better get on with some balsa bashing I guess. Time to post up a few more bits first though..

Some of the pics I posted last had the bulbous nose section ( going to call it the 'cockpit' for want of a better term!) in place on the model. I hadn't shown any pics of this bit being made or even mentioned it before. The original idea had been to carve it from pink foam, so a blank was duly cut and hacking and sanding commenced. I've never really had an awful lot of sucsess with foam carving, and this was no exception. Broke the back right off the first attempt with a little over zealous use of the Perma grit sander! Cut out another one and started again, but all I semed to be achieving was bright pink clothes from all the dust.. I often wonder just how harmful that dust can be?? Especially as it sticks to your clothes and gets carried into the house..

Early stages of foam attempt 2! Shortly before it went in the bin!

Decided perhaps foam carving isn't for me and embarked on a more traditional build for the 'cockpit', using formers and planking. I decided that apart from being... easier and stronger it would also contribute more weight to the front end to balance things up a little.. In actual fact the weights weren't all that different. The rough carved one weighed around 24 grammes and the built up one, after rough shaping , but before final sanding and tissuing came out at 32 grammes!.

I'm much happier with the balsa version, Once sealed, filled and covered it came out really well IMO. A previous model I made had a foam canopy, which was never very durable despite being epoxy covered, so although the foam attempts wasted a couple of hours before going in the bin I think this is the right approach.

Andy..

[Andy G.]

nice day so far, bit windy for flying here, so been out in the workshop pushing on a little with the drone build and also with a couple of other 'concurrent' projects. Been cutting out and trimming the aileron servo bays in the wing today and shaping up the ailerons, hopefully get them fitted in by the end of the week, although I have a very busy 3 or 4 days coming up around the Bank holiday weekend, with my other hobby, which will pretty much put paid to any building or flying for at least 4 days..

Anyway.. thats the preamble done, so posting a few pics showing the colour scheme so far on the drone. As I said at the start it is based on U.S Customs and Border Protection scheme. The Grey and Blue finish is sprayed, from Rattle cans, the red and white done with Profilm..

I'll post the full size drone pic again here for comparison.. ( don't look too close.. it is only SEMI Scale!.. )

Probably won't get any more postings in before the Bank Holiday weekend, so hope you all have a good one, with plenty of flying weather!!..

Andy..