The idea for our project came from a meeting at the Cerebral Palsy Research Foundation (CPRF), where one of the residents expressed a desire for a way to control the pointing of her single lens reflex (SLR) camera. A web search revealed that there are commercially available motorized camera mounts, but they seem to be aimed at professional or serious amateur film makers. The available camera mounts are large and have 360 degree motion on three axes. They do not appear to be suitable for someone confined to a wheelchair to use.

We decided to try to make a much smaller and lighter device. We felt that motorized control of two axes would be sufficient for still photography, and that complete 360 degree pitch motion was unnecessary.

Our first prototype was constructed mostly from wood, and motion was provided by two servos using pushrods. It was too big for mounting on a wheelchair, and did not provide the accuracy we wanted   but seemed to be a step in the right direction. The motion provided by a servo (approximately +/- 15 degrees) was too small for the pan axis. See Fig. 4.

Fig. 4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Then we worked on improving our second prototype depending on the feedback we received from our client and many people we had met during the open house. We improved the first prototype by exchanging the wood plates for a plastic box. The rotation motion was changed from a pushrod to a gear set driven by a continuous motion servo. This project was powered directly from an external power supply using a USB cable. Tilt motion was still provided by a pushrod. See fig 5.

Fig. 5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Feedback from our client indicated that a larger range of pitch motion was needed. For the third prototype, we replaced the up and down movement servo to a motor providing 2,995 in.-oz. of torque at 1 RPM.  This high torque is needed to hold the camera in place against the camera’s weight. We powered the project with a rechargeable battery.