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Wetlands Scientist
08-28-2006, 08:44 AM
I'd like to explore the possibilities that high resolution digital, low-level aerial photos could be used to characterise the plant growth in a wide range of wetlands that are part of a major WWF wetlands conservation programme here in Pakistan. Most of these wetlands are difficult to access and very hard to move about in or on during survey work. Ideally, I'd like to develop a photo-sampling programme based on an electrically powered RC model.
I have about nine years of low-key RC flying experience. I have scratch-built a conventional 40 trainer and later a 40 low wing. Purchased my first electrically powered model, an EP-Sailor, just three moths ago.

Here's a rough spec:
∑ Portability: Electrically powered RC model that could be disassembled into a 6"x6"x48" transport case suitable to be carried by jeep, canoe, mule, yak(no kidding), human porter, etc.
∑ No undercarriage: Hand launch/belly landing.
∑ Maneuverability: For landing in tight places, ailerons may be necessary.
∑ Camera: High resolution digital camera, 5+ megapixels, with automatic exposure control and electronic shutter release.

Iíd appreciate hearing form anyone who has done something similar to this . . . .
Kind regards,
Richard

Kosh
08-28-2006, 09:05 AM
Hi Richard and Welcome to Wattflyer !!!

You have thought out just what you need carefully and there are a few planes that will work nicely for your project. First off I would really think about a foam plane as it floats should it ever go down in the water. The standard Mountain Models Magpie with a brushless motor and lipo power might be a fine choice. It needs no landing gear and is very rugged and durable. A brushless motor will haul a 6 to 8 ounce camera with ease and there is even a camera mount to fit the plane. I'm sure others will add to this post with a few other planes but here a few links to get you started.

http://www.mountainmodels.com/index.php?cPath=25_29_73

http://www.mountainmodels.com/product_info.php?products_id=340

rahtware
08-28-2006, 04:51 PM
Slight problems with the Magpie.. 54" ws x 9" cord.

The 6" x 6" x 48" required dimensions will eliminate many designs. I can only think of two ways to fit a plane in the proposed box.

1. Folding fabric wing (like a hang glider).

2. Glider type plane with two (or three) piece wing.

Either design would need a tail that could also be disamssembled.

An interesting design concept... What would be the exact inside dimensions of the box be?

Kosh
08-28-2006, 06:20 PM
I said the standard magpie, That has a 46" wingspan.

rahtware
08-28-2006, 09:31 PM
I said the standard magpie, That has a 46" wingspan.

Oops... This has not been a good morning for me...


As I see it the biggest problem here is the total dimensions of the proposed box. Say he had a box made out of metal and these were it's inside dimensions... He might be able to squeeze an 8" wing in at an angle, but that leaves little room for the fuse and tail.

I have an Electra glider that I built to fit in a box (a long time ago). Never built the box, and the glider is up in the rafters, but it would probably fit in his box if it was 8" x 8"! A wing with a 6" cord is quite small... 48 x 6 = 288sq/in... Even the 46" MP has 414sq/in of wing area.

Which brings me back to a folding rogollo wing, or a two/three piece wing. A multi piece wing built like the Electras (48" center section and 2, 24" outer wing panels) would give 96 x 6 = 576sq/in WA. This is more than the MPAP (486), but less efficient at lower speeds so should work out to be about the same.

As I said, an interesting problem.

aviatordave
08-28-2006, 10:21 PM
Well maybe I can help with the camera and electronic shutter.

This is an IR control, available at www.hexpertsystems.com (http://www.hexpertsystems.com) (prism switch)

You can google search these cameras and find the best suited to what you need. Some listed here are less than the 5 mp, but this will give you an idea whats out there for this particular switch.

Pentax Cameras that support the Pentax Remote E or Remote F
- zoom and shutter control

Pentax Optio: S, S3, S4, S40, S4i, S5i, S50, S5n, S5z, S6, A10, SV, 750Z

Pentax APS cameras, SLR (ZX-7), EI-200, 928MOlympus Cameras that support the Olympus RM-1 or RM-2 Remotes
- shutter control only

Olympus C7000Canon Cameras that support the Canon RC-1 or Canon WL-DC100 Remotes
- zoom and shutter control

Canon: PRO90, S60, S70, G6, ELPH, ELPH 490Z, SureShot Z135, Rebel 300D,

EOS Elan II/Elan IIe, EOS Elan, EOS 10S, and EOS IX. Nikon Cameras that support the Nikon ML-L3 Remote
- shutter control only

Nikon N65, N75, D70, D70s, D50



Another switch that can be used on most cameras is located here: http://www.askmanap.com/singleswitch.html


This switch requires you to open your camera up and place the output of the switch in parallel to the button. Some people shy away at this due to warranty issues or resale.


Most cameras that people use here are 10 oz or lighter (mostly the 'point and shoot' cameras) on planes. A site to compare cameras is www.dpreview.com (http://www.dpreview.com)


Good luck, welcome to the forums and let us know of any other questions.


Dave

Kosh
08-28-2006, 10:28 PM
I was thinking of a removable rudder but it would be a very tight fit. After checking the elevator it just wont work as it 19" wide and unless all tail feathers were made removable. While it is possible I'm just not sure how practical it would be and your "folding fabric wing" might really be the answer here.

ForestCam
08-29-2006, 12:26 AM
Maybe a "mutt" plane is the answer. My first plane was a wing dragon and the best part about it was the fact that it could be completely knocked down and put back in the original box in a matter of minutes. The fuse would suck for AP but the plywood joiner on the wing was glued on one side and slid into a birtch re-enforced slot in the other side, taken down it's only 22' x 8". The tail would be ideal too because the horizontal stab and the rudder are both held on by two small thumb screws tothe fiberglass tail tube and are easily removed.

Couple the wing and the tail with rahtware's "Point & Shoot Special V2" design and I think you'd have a winner.

rahtware
08-29-2006, 05:35 AM
I can't believe how much time I used to put into building a plane...

Here are pictures of the removable parts for my Electra. The only part that wouldn't fit in the proposed box is the rudder which could be made to fit. This is my own design that I built into my first plane (Gentle Lady) over 25 years ago.

15924

15925

15926

15927

Everything is held to the fuse. with 3 small screws and two small machine screws and blind nuts.

rahtware
08-29-2006, 04:06 PM
How could I for get the Ventura...

5" x 39" wing, totaly removable tail parts, only two bolts hold everythig in place! This is a tiny plane, but shows what could be done to reach the required goal.

15941

15942

Eric_N57105
08-30-2006, 06:07 AM
EasyStar would meet most of the requirements outlined so far. Tough Elapor foam. If the tailfeathers are made removeable, it easily fits back into its 6x8x35" box. With 54" wingspan it has the payload capability and it is very stable for low and slow flight. Easy to repair in the field far from hobby shops.

With no prop or motor to contend with in the nose (it's a pusher), camera mounting options are almost infinite. Many pilots just remove the canopy and slid the camera into the spacious cockpit. Since the application requires hand launch and belly landing, the camera would be protected.

It wouldn't even be that difficult to hack the entire nose OFF, and fabricate a faired mount with tilt and pan.

Eric
www.ke6us.com

Derick Veliz
08-30-2006, 03:48 PM
Sorry this is a hard one.

I think the Easy Star and/or Wingo (or even your own design) are a good choice, but if the areas "are difficult to access and very hard to move about in or on during survey work".

I wonder what kind of airspace you have there, here in New England it's very hard to accomplish I've done several “work” for Wetland Conservation Projects and it's not easy, especially when there is no area to fly or client is looking for a straight down photo of a large area.

rahtware
08-30-2006, 06:42 PM
I have to believe that the first guy to fly a Wingo straped a camera on it for the 2nd flight... As with the Easy Star there is no way that this great plane would fit in a 6" x 6" box.

Derick Veliz
08-30-2006, 06:52 PM
I know, these airplanes don't break down to fit in a small box, but if you want to take your plane with you, some thing has to give up.

When clients hire me and I have to take a real airplane to get to the target, I used to put my planes in a very small luggage, as of today I ship them.

rahtware
08-30-2006, 08:20 PM
I know, these airplanes don't break down to fit in a small box, but if you want to take your plane with you, some thing has to give up.

When clients hire me and I have to take a real airplane to get to the target, I used to put my planes in a very small luggage, as of today I ship them.

Derick

I understand this, but I thought the exercise here is to come up with a plane that will fit in an existing box... At least that is how I deciphered Richards post.

Good web site, great pictures.

Eric_N57105
08-30-2006, 11:21 PM
I have to believe that the first guy to fly a Wingo straped a camera on it for the 2nd flight... As with the Easy Star there is no way that this great plane would fit in a 6" x 6" box.

But it fits perfect in 6" x 8" which is what it came in originally. Maybe Richard can clarify that it has to fit in an existing 6x6x48" box with no possibility of going to 6x8. As I said, with removable tail, it fits in 6 x 8 x 35.

Eric
www.ke6us.com

fdix
08-31-2006, 01:07 AM
Interesting challenge... Why not build something new?
In a few hours I came up with this.

Wing with max span that will fit in the box, lots of chord (for higher Re numbers and thus slower flight) a chord this high is possible because the wing is in two pieces. I hope the attachments make the concept clear, the front and back halve would be joined by carbon tubes, wing would be full epp. Will this work? The system should give a good enough joint, but it sure has to be tested.

V tail would also be full epp. I for now just concentrated on having the right area, chord would be a bit less and span a bit more than in the images.

Fuselage moulded of Kevlar, you might notice that it is rather wide. If you fly in wetlands it might come handy to be able to land on water...

Motor would be mounted on a pylon above the wing. I don't have any experience doing aerial photography so I don't have a precise idea where and how to attach equipment.

This is just an alpha version; many changes would be made before cutting a wing or making a fuselage mould. What do you guys think so far? Comments suggestions?

ForestCam
08-31-2006, 02:03 AM
What if you were to make the wing like you have there but make it 6" with 2" ailerons and a single mount hole in the center to act as a hinge?

fdix
08-31-2006, 02:29 AM
Yep that could also be a good idea. But you would loose a bit over 20% chord and therefore also 20% wing area.
What if you push the concept further and make a 6" wing with a 6" aileron? You would have a variable chamber airfoil! Maximum lift coefficient of such a wing would probably be very high, interesting for slow speed landings...
I'll run some tests in the morning with xfoil. Now I'll better get some sleep :D

rahtware
09-01-2006, 01:21 AM
Yep that could also be a good idea. But you would loose a bit over 20% chord and therefore also 20% wing area.
What if you push the concept further and make a 6" wing with a 6" aileron? You would have a variable chamber airfoil! Maximum lift coefficient of such a wing would probably be very high, interesting for slow speed landings...
I'll run some tests in the morning with xfoil. Now I'll better get some sleep :D

Man you left me hanging there....

I could immediately envision what you were talking about.

I used to have a small biplane thatís wings were simply two flat pieces of balsa joined at a slight angle along their length. This gave the wing a slight under camber. I don't know why your idea wouldn't work and very well. Would you set it up with the spars as the main hinge and the front half of the wing attached solid to the plane, and the aft section moveable?

It wouldn't take much movement to effect flight, and in this configuration the servos could be set up in a flaperon mix. I guess the main question is if the whole thing would bind up, and if the servos would be strong enough.

fdix
09-01-2006, 03:41 AM
Yes front halve attached solid to the plane. I would glue a say 10/8mm carbon tube to the epp and then put a 8mm tube trough it. Like this you have carbon rotating in carbon.
Using a pair of standard class digital servos torque should not be a problem.

Now for the airfoil... As reference I used a E399 at 250k Re because I've worked with this airfoil before. Tests using a MH42 at 200k Re, so at even slower speed than the E399, look rather promising. The idea seems to work.
With 6 deg flap at 6deg of incidence we have a coefficient of lift (Cl) of almost 1.2.

Now before going any further we need to know from our AP experts what the ideal mounting system and position for the photo equipment is!
C'mon guys let's hear some ideas!

rahtware
09-01-2006, 03:53 AM
My input is a "cockpit" mounted camera, in front of the wing, in case of water/hard landings the camera will have more protection than a bottom mount. Trouble is, this type of mounting won't allow taking pictures pointing down. Skid landings, no landing gear, do to poor landing areas.

How about a Nikon Coolpix L4? I see these at $130 (with a 256m card). An L3 is hovering around $180 with no card.

ForestCam
09-01-2006, 04:14 AM
If you mounted the camera inboard and made a section of the belly out of thin lexan you'd solve all those problems.

ForestCam
09-01-2006, 04:21 AM
Oh and BTW, if you're going to be out in the middle of no where you might want to look into one of these to recharge your batteries!

http://www.siliconsolar.com/shop/catalog/Flexible-Solar-Panel-10-Watt-p-54.html

:D

Kosh
09-01-2006, 05:38 AM
I would like to see a nose mounted camera that can swivel up (level) and down 90 degrees yet still turn left and right 180 degrees. This would give the best possible field of view and still be easy to access. I'm really not concerned about possible camera damage being in front as it can be protected with a few round wires. Most cameras are in the 5 to 6 ounce range so it may be a short nose to balance out but you would know better on that part. Thanks for taking a interest in this fdix. :)

Grasshopper
09-01-2006, 06:03 AM
My input is a "cockpit" mounted camera, in front of the wing, in case of water/hard landings the camera will have more protection than a bottom mount. Trouble is, this type of mounting won't allow taking pictures pointing down. Skid landings, no landing gear, do to poor landing areas.

How about a Nikon Coolpix L4? I see these at $130 (with a 256m card). An L3 is hovering around $180 with no card.

I'm using the L3 on my Magpie and it gives pretty good results. Here's a few pics I took last night.

Kosh
09-01-2006, 06:11 AM
Good stuff GH, Sure doesnt take long to get hooked on this and your shooting like a pro now. :D

rahtware
09-01-2006, 09:12 AM
Yes front halve attached solid to the plane. I would glue a say 10/8mm carbon tube to the epp and then put a 8mm tube trough it. Like this you have carbon rotating in carbon.

Something was bugging me and I finally figured it out. Cabon on carbon, this is cause for worry as the friction will cut away at the tubes. In a standard wing, CF tube in CF tube works because there is little movement of the tubes. In our proposed setup there will be a constant grinding of CF (a great abrasive) on resin.

Maybe a good lube on the tubes would fix this.

fdix
09-01-2006, 10:09 PM
If you mounted the camera inboard and made a section of the belly out of thin lexan you'd solve all those problems.

The problem would be that you'd often have to replace the lexan because of the belly landings.

Friction between carbon would be solved using tubes with a polished surface and as rahtware suggested with a good lube

For the camera mount... I tried various things in CAD but the only solution that convinces me is the one in the attachments. With the camera out a mix would be necessary to prevent the plane rolling to that side. Dimensions are those of a Coolpix L3

rahtware
09-02-2006, 05:57 AM
FDIX

Try a sliding door under the camera... It wouldn't have to be preaty, just keep out the garbage when landing. If we are working on water landings the door could slide in a grove that is coated with vasoline, or even weather strip can be made to be water "resistant".

fdix
09-06-2006, 12:22 PM
The problem with a sliding door is that you insert a weak point in the structure, it is not that easy to build and you would need one more servo. You also couldn't take pictures sideways.

By the way where is our wetlands scientist? You still alive mate?

I'm rather busy at the moment so sorry if I don't answer immediately!

ForestCam
09-06-2006, 06:18 PM
Actually if you made it with a little tab or a skid that stuck down a bit it would snap shut by itself as soon as it touched the ground.

JediFlyer
09-06-2006, 06:57 PM
Hey...I took this with my EZ* a week or so ago in our Impoundment...I could have gotten lower...in a few of the passes we found water we didnt know we had which for us is a GOOD thing...Its kinda jerky...but the wind was coming up...we had just carried up a bunch of heavy equipement for a work day and I was flying in front of a few friends and my DAD for the first time so I had the jitters. I think with a few mods the EZ* would be good choice for all around safety around water for every day use...I could have landed it in the marsh grass and it would have been ok..

http://media.putfile.com/Impoundment-2006

fdix
09-09-2006, 12:41 AM
Actually if you made it with a little tab or a skid that stuck down a bit it would snap shut by itself as soon as it touched the ground.

But that would not be too good in case of a water landing... :p

I'd say let's wait for wetlands scientist to reappear. I see no point in designing a special plane just for the hack of it.

rahtware
09-09-2006, 09:06 AM
JF

Fun video... I could tell the wind was up by the way the EZ was climbing while staying over the same place!