Aspire EP RTF Electric Sailplane. 2
meter (78") wingspan.
In the summer of 2003, I bought an Aspire EP electric motor powered
sailplane from my local hobby shop, HobbyTown USA in Longmont.
This is a complete, nearly RTF (ready to fly) sailplane, which includes
everything you need to get started, including the radio transmitter and
receiver, a battery pack, and the sailplane is nearly completely
built. I was in the air in about 30 minutes. The Aspire
features balsa and plywood construction, and is covered in Ultracote
plastic film for the wings. The wingspan is 2 meters (78
inches). The supplied battery pack and motor offer adequate, but
not stellar, performance, especially at this altitude (5100 ft).
I had flown
R/C sailplanes 20 years ago, and was very proficient at it. It
didn't take me long to get back into the swing of things, and I had
only a few very minor skirmishes with the ground. I flew it
hundreds of times during the summer of 2003, and then in the spring of
2004, started flying it again. I had been using various digital
cameras since 1998. I noticed how small and light they had
become, and how good the picture quality was. I toyed with the
idea of mounting a camera to the model airplane to take some aerial
photographs. Finally, in August of 2004, I decided to go ahead
and try to make it a reality. I started looking at small digital
cameras, but the ones with decent resolution ( 2 Megapixel or greater)
still quite expensive, and I didn't like the idea of putting a $300
camera on a model airplane. I had no idea how well it would
I found what I thought might be a good solution at Office Max for
$80.00. This Digitrex DSC-3000 3.2 megapixel camera is relatively
about 5 Oz., and best of all takes AA batteries (it EATS alkalines, so
use NiMh rechargeables). It has a SD (Secure Digital) memory card
slot, and a USB interface. The standard 8MB built in memory can
only hold about 8 pictures at the default resolution of
2048x1536. I bought a 128MB Secure Digital card for approx. $30
from Office Max, which will hold over 100 pictures. I have also
taken a 9 minute .AVI movie using this card.
I wanted to be able to take pictures by command. The problem was,
the Aspire EP included only a 3 channel transmitter (rudder, elevator,
and throttle). I needed another channel to control a servo to
snap the shutter on the camera. The Aspire's receiver IS a 4
channel receiver. By this time I had another R/C sailplane, this
one with a 4 channel transmitter. I swapped the crystal into the
4 channel transmitter, bought a micro servo, and tested the
functionality of the combo. Everything seemed to work fine.
I originally mounted the servo to operate the shutter button on top of
the camera with silicone RTV (bathtub caulk). This would allow me
to remove the servo (and RTV) completely from the camera, if need
be. The resulting pictures turned out so well, I decided to go
ahead and use 1 drop of CA (cyanoacrylate - super glue). 1 drop
is sufficient, because they are two flat smooth surfaces (camera top
and servo body). This is exactly the type of application the CA
glues were intended for. I haven't had to pull it apart yet, but
I don't imagine there would be too much damage to either the servo or
the camera when I do.
Micro Servo attached to the top of digital camera, using 1 drop of CA
I then set up the Hi-Tec HS-81 servo travel (actually just
re-positioned the servo
arm) so that at full travel, it operated the shutter button. In
the setup menu of the digital camera, I disabled the
flash, and disabled the auto-power down feature (battery saver). I
didn't want the camera shutting off by itself in mid flight, with
no way to turn it on again from the ground. The camera's
auto-power down feature automatically shuts it down if you don't take a
picture in 3 minutes. Fortunately, there was a menu option to
I mounted a piece of 1/8" aircraft plywood, with a hole drilled for the
1/4x20 tripod mount screw, on the bottom of the plane. Another
piece of plywood on the inside floor of the plane, and 3 wood screws
secure it to the fuselage. This allows me to easily remove the
camera from the plane for charging the batteries, or connecting the USB
cable to download the pictures from the camera.
Camera attached to airplane. The camera is mounted on the C/G
(center of gravity) of the airplane.
First flight - August 04, 2004 - Nearly flew it into the ground after a vigorous hand
launch. It required a bit of up elevator trim, but otherwise
seemed pretty stable. The climb performance wasn't nearly as
good, due to the added weight (6+ ounces). First flight getting
used to the handling of heavier airplane, I didn't get much
altitude. Here are pictures from the first few flights. These
pictures are scaled down to 640x480 pixels for the web. The
acutal pictures are 2048x1536 resolution, and are fairly good
quality. Not nearly as good as my Sony Cybershot pictures, but
the camera only cost $80.
Xilinx building back parking lot in SW Longmont, CO.
SE corner of Clover Creek subdivision in Longmont, CO.
That's my house in the very corner, brightly illuminated fence angled in back yard.
White speck just outside of fence (next to small tree) is me. :)
Clover Creek Dr. Note neighbors oblivious to quiet electric
Adaptec building in foreground, Xilinx building in background.
(Plan to add additional photos as time allows)
Pictures of SW Longmont, CO. Aug. 29, 2004 - Digitrex DSC-3000 3MP CMOS imager camera.
Pictures of Boulder Rifle Club in N. Boulder, CO. Sep. 11, 2004 - Sony DSC-U50 2MP CCD camera.
Pictures of SW Longmont, CO. Sep. 12, 2004 - Sony DSC-U50 2MP CCD camera.
Pictures of SW Longmont, CO. Oct. 2, 2004 - Sony DSC-U50 2MP CCD Camera
Pictures of Roger's Grove Park, Longmont, CO. Oct. 21, 2004 - Pentax Optio S4i 4MP CCD Camera
Pictures of Roger's Grove Park, Longmont, CO. Oct. 31, 2004 - Pentax Optio S4i 4MP CCD
38MB Movie, set to music by the Foo Fighters in Windows Media Player format - Digitrex DSC-3000 3MP CMOS imager camera.
This page and all photographs copyright ©2004 - Greg Douglas.