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dome78's blog
Posted by dome78 | Nov 25, 2013 @ 12:40 AM | 1,407 Views
In my previous post I showed some in flight footage of my purpose built camera ship. If I find time I'll go over the details but here are the specs for now:

Wing: Radian Pro converted into three piece wing to facilitate easy transport. The center section is fixed to the booms and semi-fixed to the fuse. I had to cut the flaps along with the wing and only the inner flap section of the original wing is operational. I added a CF spar (10mm) and extended the original spar length to retain more strenght in the wing. There is a smaller rectangular spar in the back of the wing with a round hole that is used with attach the outer sections together with the larger 10 mm spar. A magnetic mechanism locks the outer wings to the center section. The ailerons are identical to the Radian Pro.

Fuse: The fuse is a 2" square built from balsa, bass and partially reinforced with 3mm ply. The nose and tail cone are attached through magnets.

Booms and tail: I used 1/2" balsa squares for the booms. In the front there is a 1/2" bass piece that the motors attach to (stick mount). The tail surfaces are CF strip reinforced 6mm depron with twin rudders.

Wing span: 2m
Length: 95 cm/35 inch

ESC 2 x 30a Sky Power ESC from HeadsUpRC
2 x Firepower Sport 450 currently on 9x4x3 GWS
5 x TowerPro SG92R 9 gram servos
2 x HXT500 6 gram servos on the rudder
2200mAh 3s lipo
500mAh 3s for Goodluckbuy gimbal
Posted by dome78 | Nov 14, 2013 @ 01:16 AM | 1,347 Views
I got a 2-axis gimbal from Goodluckbuy. For 99$ shipped from China I am quite happy with it for what it does: http://www.goodluckbuy.com/dji-phant...hy-blalck.html

It is somewhat on the heavy side weighting in around 350gr with a Hero3. It worked straight out of the box. I only had to invert the the sensor using SimpleBGC. The gimbal seems to drift a bit and will start to "lean" to the left after a couple minutes.

I built a custom airframe around the gimbal to work around the funky rules the city setup at my usual flying field (front prop only). Anyways, a quick video of the gimbal action and some inflight footage below.

Stabilization demo:

gimbal test (0 min 14 sec)


...Continue Reading
Posted by dome78 | May 04, 2013 @ 02:33 AM | 2,026 Views
Fun Cub @ 240 FPS (0 min 46 sec)

Posted by dome78 | Mar 18, 2013 @ 11:35 PM | 1,931 Views
This is my take on building a straight Fun Cub wing without dihedral. I used a 8mm 36 inch carbon tube (6$ at LHS) and a Dremel rotary blade and sanding bit.

I sacrificed the separable wings for a one piece wing with this mod. Cut the tube to fit the long groove in the wings. The remaining tube will fit in the short groove. I cut and sanded off the lower half of the two wing joiners tubes with the Dremel tool and then fed the carbon tubes though. Glue in wing and done.

I also bought a 6mm tube to see if I could join the fiber glass tubes that came with the FC. The idea was to use the the 6mm tube as an inner tube glued to the wing mount. This would have retained the two piece wing. But LHS only had a rather expensive 6 mm (5mm or 5.5 mm ID) tube for 10$. I figured this would not be beefy enough to hold the wing together and shleved the idea.
Posted by dome78 | Mar 17, 2013 @ 11:50 PM | 2,678 Views
I finished my second Fun Cub today.

- Turnigy 60A ESC
- EMAX 2815/09
- 12x6 APCe (390W WOT on ground)
- 2 x D-MG16 (Elevator/Rudder)
- Turnigy 9gr Flaps/Ailerons
- CG on main spar

- Lights: 2 LED corn lights and LED strips
- Added two springs to the gear
- Sullivan tail mod
- Straight wing, no dihedral
- Floor stiffener from morganmill.com/rc (correction: http://morganmill.com/RC/)
- Resersed one servo
Posted by dome78 | Sep 08, 2012 @ 04:17 PM | 2,461 Views
While experimenting with balsa VGs I realized they are too brittle. I knocked a couple off during transport and they are somewhat of an eyesore. So I came up with VGs from PETE plastic.

The cool thing is that I can later adjust the VG with scissors if necessary. They are flexible too so they will not come off when I bang the wing against my car.
Posted by dome78 | Sep 04, 2012 @ 03:56 PM | 2,651 Views
Yes, it hovers.

Fun Cub Hovers (0 min 30 sec)

Posted by dome78 | Aug 26, 2012 @ 02:19 AM | 2,721 Views
I added fixed slats to my Fun Cub. The goal was to reduce stall speed. I took used about an inch wide wet balsa that I wrapped around the wing to let it dry to form. Then I added little posts to get a proper distance to the wing. The leading gap is about twice as big the aft outlet.

I don't have a degree in aeronautics - just playing with an aging air frame. I did notice a higher angle of attack. Due to the wind conditions however, I could not tell if the stall is now induced later. I will report back in the comments.
Posted by dome78 | Aug 16, 2012 @ 12:15 AM | 2,455 Views
As mentioned before I used to watch MTV a lot. Another source of inspiration is the British car show Top Gear. Their camera work exceptional. Watch it for some inspiration - it's on Netflix and Amazon for free.

Filming Techniques

I have seen a lot of RC videos. There basically are three types:
  • The third person view: A person other than the pilot is filming the plane. The difficulties are keeping the plane in focus and centered and of course it requires having an camera man/woman often with questionable camera experience.
  • First person view: The pilot filming the plane in the air through a camera fixed to the head. The pilot's head is following the plane and in theory the plane is always in the picture.
  • On board view: A camera is mounted on the plane itself and records a flight while in the air. The camera either records on an internal memory of the video signal is transmitted to a ground station for live viewing (or both). Admittedly there are some really cool videos out there using this view.
All of the above are more or less easy ways to document a flight depending on what one tries to achieve. Ideally I would want to use a combination of the above.

While I have not done the first person view yet I do use the other two techniques. I build a snap-on GoPro mount that I can put in between the removable wings on my Fun Cub. It allows for forward and backward facing footage and with some GoPro adapters I can swivel the cam as well to get sideways footage. The rolling...Continue Reading
Posted by dome78 | Aug 10, 2012 @ 02:29 AM | 2,363 Views
After posting a couple videos here I got asked a number of times what equipment I use and what tools and techniques I use. I answered every one of them but figured I'd do a quick run down here for everybody to see. Disclaimer: Neither am I a professional, not even an expert nor do I have help in the process of making these videos. I thought everything myself. So by no means expect a cinematic how-to.

I'll chop this into three main steps/posts. The first and most important being the idea, equipment and pre-filming preparations. In later posts I'll cover the filming itself and finally the post processing.

Preparation and Tools

Get the tools together. I use the Hero2 camera for most of my takes. The camera retails currently at 300$. Unless you can get employee pricing or a new model comes out you will not get this much cheaper, even used. Occasionally I recruit a Sony alpha SLT33 DSLR for some takes, however the normal flying field really is not a suitable environment that I like to take high end equipment to. The videos posted earlier are Hero2 only.

Before the Hero2 I experimented with with various keychain cameras (#8 and HK "HD") but they turned out to be unsuited because of the poor video quality especially against the sun and the relatively low frame rate - I'll get to the last point later. I liked, however, the fact that I can velcro these light weight cameras pretty much anywhere on the plane for interesting angles without changing the flight...Continue Reading
Posted by dome78 | Aug 06, 2012 @ 09:32 PM | 2,623 Views
Finally had time to do another video.

Fun Cub "Target" Practice (3 min 58 sec)

Posted by dome78 | Apr 16, 2012 @ 11:11 PM | 2,575 Views
Untitled (3 min 23 sec)

Posted by dome78 | Nov 23, 2011 @ 01:14 AM | 3,000 Views
My Fun Cub configuration

NTM Prop Drive Series 35-36A 910Kv / 350W
12 x 6e APC = 330W on 3s
40 amp plush controller
Spektrum AR6110e -> later upgraded to Orange 9CH with additional UBEC 5A
2 Hitec 81MG for elevator/rudder
4 HXT900 for flaps and ailerons
and some lights

DX7 mixing
mixing flaperons to flaps:
Gear -> Aileron -0/+40 on flap2
Gear -> Gear 0/-80 on flap2

Mixing flaps to as ailerons:
Aile -> Aux2, +20/+20 on flap0
Aile -> Flap, -20/0 on flap0

dual ailerons:
aile -> gear, +100/+100

dual flaps:
flap -> aux2, +100/+100

Elevator flap mixing:
Flap 20% deployed -> elevator 18 down
Flap 100% (90 deg) -> elevator 40 down