Large scratch built Quad Copter aerial photography

by kuehn | February 6, 2015 | (7) Posted in Projects

TOTAL COST: $113.89

Creative engineering on the adjustable camera shock mount and the landing gear mounts and legs.

I've recently finished a new large quad-copter designed to carry my Nabi Square HD camera aloft (excellent GoPro clone camera). I was surprised to find that this quad-copter is a better photography platform than my Tri-copter. It has a yaw rate (rotation to the left or right) that is smoother and more stable than the tri-copter. It is also more stable in a hover. I've been experimenting with different materials to suspend the camera underneath the copter body. It is necessary to isolate the camera from the frame vibration that is induced from the motors and propellers. Even though motors and props are carefully balanced, there is still vibration, often caused by propeller-tip flex when there is a wind gust or when there is rapid rise or fall of the copter. I've found several materials that work well...still trying to figure out what will do the best job. When vibration is transferred to the video camera, the resulting distortion is referred to as jello, since the image looks much like a block of jello wiggling back and forth.

I did much of my testing during a couple days when there was snow flying and pretty strong wind, especially when flying above the treetops. I blended together several clips from the test flights. This combined clip has been uploaded to You Tube.....see the link below. The still photos are photos taken during construction of the big quad-copter. The motor arms are 30" from tip to tip. I started out with a commercial frame (cheap copy of a DJI flame wheel frame). It flew okay but I just wasn't impressed with its flight capabilities, especially when I considered using it as a camera platform. So I built my own frame, using a LOT of materials that I had on hand. This kept the cost of the new quad-copter pretty modest, especially when compared to commercial products, which typically cost 10 to 100 times as much as my home built design.

I'm getting 10 minute flights when equipped with the camera from a 2200mah 3s zippy 25C battery. Without the camera, I've gotten close to 13 minute fights with the same battery.

BIG QUADCOPTER BUILD COSTS
I have a very complete wood working shop in my basement, so milling the 1/2" square wooden arms is a simple and inexpensive task for me.
Wooden frame arms: 1 @ 1/2 x 1/2 x 30" aircraft spruce: N/C (stock on hand)
Wooden frame arms: 2 @ 1/2 x 1/2 x 14.75" aircraft spruce: N/C (stock on hand)
Wooden frame spacer pieces, 1/2 thick from aircraft spruce: N/C (stock on hand)
5 minute epoxy to join the half moon pieces into the round frame:          $0.60
Half moon body pieces: 4 @ 4" diameter x 1.5" O.D to I.D. N/C (stock on hand)
Stainless Steel 440 hex head screws: 8 @ $0.04 each                            $0.32
Stainless Steel 440 nylon insert lock nuts: 8 @ $0.05 each                     $0.40
4 motors from HobbyKing (int. warehouse): DST-1000 @ $7.19 each   $28.76
4 30amp SimonK ESC's from ebay: Includes shipping from china         $25.26
KK2.1.5 flight control board from HobbyKing:                                        $21.99
3.5mm bullet connectors for 4 motors and 4 speed controllers:               $3.40
XT60 to 6 X 3.5mm bullet Multistar ESC Power Breakout Cable:            $3.07
4 Landing gear mounts made from copper clad circuit board material and cut off .223/5.56mm shell casings....shell tops soldered to circuit board: N/C (stock on hand)
Aluminum camera mount plus carbon fiber hollow tube: N/C (stock on hand)
Various cable ties: N/C (stock on hand)
4 landing gear legs made from broken Cabela's 220 arrows: N/C (stock on hand)
4 ping pong balls for landing gear bottoms:                                             $1.60
miscellaneous heat shrink material: N/C (stock on hand)
Self adhesive velcro material for battery attachment:                              $0.20
1/2" x 3" joining strap made from copper clad circuit board: N/C (stock on hand)
miscellaneous small screws: N/C (stock on hand)
4 aluminum motor mounts made to mount the DST-1000 round motor bases: N/C (stock on hand)
Paint, spray cans and acrylics: N/C (stock on hand)
8 hex head screws 2.5mm x 10mm to mount motors (local hobby shop): $4.00
Receiver for 9x radio, Hobby King 2.4Ghz Receiver 6Ch V2:                    $9.82
10CM Male to Male Servo Lead (JR) 26AWG -- 5 pieces used:                $2.47

SUBTOTAL:                                                                                         $101.89
fast shipping from HobbyKing International: (approximation)                $12.00

TOTAL:                                                                                                 $113.89

Big Quadcopter Build Cost with descriptive text

Video shot a sunset.  Camera mount now modified with short pieces of large silicone fuel tube lining the carbon fiber tubes...a loop of braided picture frame hanging wire suspending the camera platform. 

COMMENTS

Scott1308 on February 9, 2015
Great job. I'm all about cheap! and using what you have. I really want to build a quad for my son for under $100. Question, could you have gone with 20amp esc? Thanks!
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kuehn on February 9, 2015
Yes....I could have gone with 20 amp; 15 or 10 might even be sufficient. Do a search on Ebay for SimonK Esc's and you will find that the 30 amps are literally only pennies (maybe $0.20 to $0.30) more than the 20 amp and smaller. Given the tiny additional cost, I opted for the 30 amp ESC's. I'd been meaning to check the current draw with my Watt-Up meter, so I just did, in my living room. At lift off (I didn't push it any further) the draw was 8.75 amps and 102.6 watts. This was without the camera. With the camera and full power, my guess is that you won't be drawing more then perhaps 20 amps? Divide the various numbers by 4 and it looks like it could easily fly on 10 amp ESC's. I may fly it on 4 cell packs down the road, but even then 10 may be sufficient. Hobby King had a sale last week...10% to 30% off selected items. The motors I used here...DST-1000's...were on sale from the Int. warehouse for just over $5.00 each. I just saw that they are doing the same sale this week at regional warehouses. That presumably includes the US East and West warehouses. You might want to check for motor and flight control board prices there. Cheers! Brian Kuehn
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LordVader on February 16, 2015
That is awesome. I have the same kit as you from HK, but I am having trouble with the Qbrain and KK2 board. I'll get eventually. I like your mounts for the camera and such, good idea using fuel line.
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yellow_jacket on February 28, 2015
I HAD a DJI Phantom 2 until it took off on its own over the lake, never did find it. Anyway, since I still have the radio control and some miscellaneous items I'm very interested in building a cheaper model. I am not an experienced RC builder but I think I can follow your plans fairly well but I have a few questions.
1. I have some 8.4 Volt NiMH battery packs from a different RC model. Could I use these rather than an 11.1V LiPo? They may be too heavy but I'm more interested in staying away from LiPo since I don't already have a LiPo charger.
2. The radio control from the Phantom is 2.4Ghz 6 channel. Could I use this to fly your version of a homebuilt?
3. Could I exchange sturdy wooden pencils or dowels in place of the carbon fiber arrows without sacrificing too much add'l weight?
4. I don't believe you mentioned propellers. Do you have a recommendation for me?
5. Do you know exactly what yours weighs?
If this works, I will invest in the cheaper Nabi camera later (cuz I lost a GoPro 3+ at the same time as the Phantom 2). Thank you in advance.
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The Groundhog on April 12, 2015
Hi.

Well done for keeping your enthusiasm! I know this wasn't directed at me, however I think I can answer your questions. First of all, I don't believe the Phantom controller is compatible with any receivers other than that found in a Phantom, so I suggest buying a cheap transmitter/receiver from HobbyKing, or else it may be possible to find a replacement Phantom receiver online. Try eBay or Amazon?

In terms of power systems, I would not recommend using NiMH. I personally haven't used them, however LiPos are the industry standard, and simple, safe chargers can be picked up quite cheaply. In terms of propellers, I would suggest 8045 or 1045s for the above setup. You can find them here: http://www.hobbyking.com/hobbyking/store/__25818__8045_SF_Props_2pc_Standard_Rotation_2_pc_RH_Rotation_Black_.html

When it comes to the frame, it is extraordinarily simple. Two squares of plywood will do the trick. Pencils have a tendency to break rather than bend, however any wooden rod, dowel etc. will work fine. If you can find something that is strong yet can sustain some impact, and elevates your quad off the ground, it'll work as landing gear. I have used toy darts on a quad!

Good luck on your build. There are tons of builds like this on FliteTest, check them out.

Here is my build of my first quad: http://www.flitetest.com/articles/first-scratch-built-quadcopter

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kuehn on March 1, 2015
You could probably use the 8.4 volt NIMH packs, but if that's your plan, I would go with a higher KV version of the motor I used. The same motor comes in different windings. HK has a
D3128-1550 Brushless Bell Motor, and a DST-1200. Either of these would be a higher KV that would be more likely to work with the lower voltage NIMH packs. If the NIMH packs don't work, you can always switch to LIPO packs. The Phantom radio should work okay....my setup is Very simple using 5 channels.....four for flight control...Aileron, Elevator, Throttle, and Rudder, and one AUX channel used to turn self leveling on and off. You could use pencils or wooden dowels, but a rough lateral landing is going to break them. If you don't plan on a camera initially, don't puty any landing gear at all on it....That's how I first flew mine. I added the gear to accomodate the underslung camera. I can't give you a weight at the moment as I had a fly-away with it last week. It's in the woods somewhere behind my house....still looking. The propellors I use on this copter are GEMFAN 10x4.5; use the nylon ones to start and once you're proficient, you can switch to the "mixed Carbon" versions of same..they are much stiffer, smoother, quieter BUT also more brittle and will break more easily than the nylon versions.
Good luck with your build. Brian.
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thefrogman123 on April 14, 2015
lipo battery chargers aren't that expensive. the cheap one that I have charges 2 and 3 cell lipo batteries and I have never had an issue. I bought it from grayson hobby in the US. It was maybe $20. Good luck and happy flying!
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reodds on December 4, 2015
Hi, I realize that this article is almost a year old, but I am just starting research on a new build. I like the fact that you used wood as your frame. Is it balsa wood or another fine grained wood? Also, do you find any appreciable flex when the motors apply to the frame?
Thanks for your help!
Roger
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kuehn on January 7, 2016
Sorry Roger, just now saw your question. The wood used is aircraft grade spruce; it could just as easily have been clear pine, but I have a stock of aircraft grade spruce. There is no wood that is better for this purpose for strength versus weight. My wooden copters have crashed from hundreds of feet without any breaks to the frame. I'm currently building a bigger Hexa-copter with the same construction except I've increase the arm size to 5/8" square and 36" tip to tip.
Brian.
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Large scratch built Quad Copter aerial photography