Yesterday, members of the Robotics Club at my son’s high school went down to Monterey Peninsula College for a camera-waterproofing workshop. The cameras are for the underwater remotely-operated vehicle contest coming up in April. I blogged about an earlier workshop in which my son played with building an ROV—the cameras are for such a vehicle. [Note: this workshop was not an official activity of the Robotics Club, but just a couple of the members going to the workshop with their dads. Official activities have to have one of the high school teachers present at all times.]
There are now 13 “Ranger” teams registered (who have to use cameras to navigate their vehicles) and 28 “Scout” teams (who can watch their vehicles from the pool edge and so build simpler ROVs) for the Monterey Bay regional. The Ranger teams are mostly high school teams, and the Scout teams mostly middle school teams. Some middle schools have 3 teams entered, but the high schools seem to be running one each. The high school teams are coming from as far away as Stockton and Santa Maria (each about 160 miles from Monterey by car), so our little commute of 50 miles seems small. None of the distant teams came for the camera-waterproofing workshop though—only 3 or 4 of the more local Ranger teams were there.
The whole contest started in Monterey in 2002, but has since grown to 20 regional competitions feeding into the international competition. There are over 200 teams registered in the various regional competitions. The contest is actually international (one regional is in Hong Kong and one is in Japan and there is a team registered from Egypt), but most of the teams are still from the US.
The camera waterproofing turns out to be surprisingly easy (though I suspect that there was a fair amount of trial and error in the development of the procedure). There are full instructions posted on-line, so I’ll only include a few photos here of some high points.
They start with a cheap video camera (the Anaconda Color model SC18A camera with a 60-foot cord). I would have preferred starting with a USB camera (since we have laptops, but not old TV monitors with analog inputs), but the workshop cost only $25 per camera (including the camera, superglue, cups, epoxy, … ), which is an unbeatable price. There is a subsidy involved since the camera alone costs $50 on the web. I think that there is some difficulty finding USB cameras with 60-foot cords also, and we really don’t want to have to waterproof USB connections.
The first step is to remove the camera from the housing, which requires destroying the housing, since the camera is glued in.
The next step is to fix the focus of the camera, since it can’t be adjusted after waterproofing.
The camera is glued lens-down in the bottom of clear plastic container.
A slow-curing epoxy (EnviroTex Lite pour-on high gloss finish) is used to pot the camera. Faster epoxies could be used, but the exothermic reaction of the epoxies can overheat and damage the cameras, so a slow epoxy is safer.
Because the epoxy takes many hours to set, the workshop organizers had us leave the cameras in the classroom and will mail us the waterproofed cameras in a few days.
Only one boy at the workshop managed to superglue his fingers together, and they had some acetone available to release him. (Luckily for our pride, it wasn’t one of our club’s members.) The workshop was fun for the students and they got a lot of good advice on ROV building from Jeremy Herzberg, a technician at Monterey Peninsula College who has been involved in the underwater ROV competition for several years.