It is very important that you read the entire presentation before you start, common mistakes are highlighted at the end. By Jim McDonnell 6/15

Transcription

1 It is very important that you read the entire presentation before you start, common mistakes are highlighted at the end. By Jim McDonnell 6/15 1

2 More Art than Science Over the years MATE has developed several methods to waterproof cameras for your ROV. All the methods work, though they may not all be appropriate for your team. Students can be tough on their ROV and as the ROV goes through testing and reconfiguration, camera tether wires get pulled apart and the cameras are banged around resulting in cameras suddenly failing. The goal of the this method is to develop a Ruggedized camera that does not require any soldering of those itsy bitsy camera wires for Scout or Triggerfish ROVs that need only 1-2 cameras. 2

3 Engineering is all about tradeoffs PRO Rugged, a nick in the tether will not cause the camera to fail All connections waterproof Students can build it without soldering those itsy bitsy camera wires Reasonable cost Optimal for ROV that needs 1-2 cameras CON Heavy 5 inch tube filled with epoxy Lenses can be scratched Epoxy can be messy to work with Caution Follow epoxy, acrylic glue/cement, and solvent safe handling instructions provided by the manufacture. 3

4 Materials CCD auto backup camera, ¼ inch flush mounted preferred 50 foot camera tether A five inch long by 1.5 inch OD acrylic tube A 1.5 inch acrylic disc at least 1/8 inch thick 2 inch long stainless pan head screw Five minute epoxy Acrylic gap filler cement Slow to medium setting potting epoxy (4.5 oz per camera) Hot glue, popsicle sticks, and tooth picks 4

5 What does Weather-proof Mean? Definition of IP Codes (Ingress Protection) IP65= Protected against low-pressure jets from all directions - limited ingress permitted IP66 = Water projected in powerful jets (12.5 mm nozzle) against the enclosure from any direction shall have no harmful effects. IP67 = Ingress of water in harmful quantity shall not be possible when the enclosure is immersed in water (up to 1 m of submersion). IP68=The equipment is suitable for continuous immersion in water under conditions which shall be specified by the manufacturer (immersion beyond 1 m). 5

6 Prepare the Camera Remove any brackets from the camera and the protective lens cover. 6

7 Prepare the Lens cover Draw an X on the blue protective plastic on one side of the circular lens covered. The purpose of the X is so that you can keep track of the protected side of the lens disk. Remove the blue plastic cover from the other side of the circular lens. 7

8 Attach Acrylic Lens to the Camera The purpose of this step is to physically attach the acrylic lens to the camera by applying five minute epoxy with a toothpick to ONLY a few spots on the face of the camera. Once the epoxy is applied gently center the acrylic lens onto the camera face and let it dry. 8

9 Equipment and Technique There are many CCD backup camera s available. The one on the left is a ¼ inch flush mount and provides a bigger face for the students to apply epoxy on. The picture quality of the two cameras are the same. An easy way to manage the camera cord is to mount the camera through a piece of cardboard so that the cord dangles below and is out of the way. 9

10 Seal the Camera to the Lens The purpose of this step is to seal the camera to lens by adding a layer of 5 minute epoxy to where the edge of the camera face meets the surface of the lens. Apply epoxy by holding the epoxy covered toothpick still and slowly rotating the camera. Epoxy is your friend, more is ok though avoid getting any on the outer edge of the lens cover. 10

11 Notch Back of Tube for Tether Exit Make a V notch in the bottom of the acrylic tube about ½ inch deep. The purpose of the notch is to provide a path for the camera tether to leave the side of the tube. This will allow for the camera to be easily mounted without pinching the tether. The notch can be cut with a hacksaw, dremel, or file. 11

12 Glue to Lens onto the Tube Apply a liberal amount of acrylic glue or gap filler cement to the tube and center the lens cover onto the end of the tube that does NOT have the notch cut into it. You want the glue oozing out the sides of the union, may not be pretty but insures a complete seal. Apply a weight to the push the lens down into place and let the glue dry at least an hour. 12

13 Prepare Tether Unwrap the 50 foot tether saving the two twist ties and BNC to RC (the silver things). Cut the red RC connectors off of the tether at both ends (they are for audio). Plug the camera into the tether making sure the connections are snug. 13

14 Bundle the Tether into the Tube Gather up yellow and red tether connector and the black tether lump and place them side by side. Using one of the twist ties from the tether packaging tightly tying all the wires and lumpy stuff together. Carefully push the wire bundle into the tube. Make sure all the cables in the tube are about ½ inch below the top. 14

15 Hot Glue the Tether Out the side Add a little hot glue to the bottom of the grove you cut into the tube, pull the tether through the grove and apply more hot glue to the top of the grove, sealing the tether to the tube. You will be filling the tube with epoxy so the hot glue keeps the epoxy from leaking out. 15

16 Mix the Epoxy Any slow to medium setting epoxy can be used (you do NOT need to use marine grade epoxy) just make sure you follow the mixing instructions. When epoxy does not set up it is because the mixing amounts were not correct. Use a medicine measuring cup to help get the amounts correct. Mix the A and B parts of the epoxy with a popsicle stick before you pour it into the tube. Do not use fast setting epoxy, it cures at over 200 F and can damage the electronics. 16

17 Almost Done! Drill a 11/64 hole through the popsicle stick and tread the pan head screw through it. Slowly pour the mixed epoxy into the tube. Place two tooth picks over the top of the tube and push/ lower the popsicle stick and screw into the epoxy. About ½ inch of the screw should be in the epoxy. It does not matter if the screw is off to one side or directly centered in the tube. After the epoxy has cured remove the popsicle stick. You may need to break it off and it is OK is some wood remains. Test your Camera, you are done! 17

18 Done! You know have a pretty rugged camera that should be usable for several years. Keep in mind you still need to use the camera power filter to provide power to your camera and video display see triggerfish SID. The video displays can support two cameras though you may need a RC adapter. 18

19 It happens and what to do about it minute epoxy gets on the camera lens Clean off with paint thinner or denatured alcohol before it dries. Follow solvent safety handling precautions. 19

20 It happens and what to do about it - 2 Epoxy leaked out through the lens while it was curing. This happens when insufficient acrylic glue was used or the glue surfaces were not clean and square. The blue plastic has protected your lens cover, simply break the camera away from the leaked epoxy and peel off the blue plastic covering the lens. To make sure there aren t any gaps between the lens and the front of the acrylic tube add a layer of acrylic gap filler cement all the way around the seem where the lens and the tube meet. It will not look pretty but if will not leak either. 20

21 It happens and what to do about it - 3 One of the wires was not covered by the epoxy. The main reason for the epoxy is to protect the wires from being abraded or cut. Add more epoxy until all the wires are covered. Some of the wood from the popsicle stick stuck to the epoxy at the top of the tube. This is more of an aesthetic issue as long as the wood does not hamper the mounting. Some of the bulk of the wood can be removed with plyers, a file, or side cuters. 21

22 It happens and what to do about it - 4 Some of the 5 minute epoxy squished over into the camera lens when the acrylic disc was added.. This happens when too much 5 minute epoxy is placed on the camera face. As the acrylic disc is applied the epoxy squishes over into the camera lens obscuring a portion of the view. There is really nothing you can do about this except make another camera or use the one you made with a partially obscured view. Epoxy Camera Lens 22

23 Spills Happen be Prepared -5 Epoxy takes between 4-12 hours to cure. During the curing time you are at risk of a spill. If the epoxy gets on the camera lens, the camera is ruined. If you want to have 2 cameras on your ROV buy 4, make 4, and plan on one failure, and one to have as a spare. 23

24 By Jim McDonnell 6/15 24

25 Video System The Video system consist of the Camera (power) filter, Camera, and Monitor /LCD screen 25

26 Camera Power Filter Pufferfish Camera Power Filter Triggerfish Camera Power Filter Power Plugs to Camera and LCD 26

27 Why you need an Camera Power Filter An Electrical power filter is similar to a surge protector. When Electrical motors are rapidly turned on or off voltage spikes of up to + _ 200V can shoot from the motors back through your wires. These spikes only last micro seconds but in that time they can burn out sensitive electronics.like your camera and LCD screen. Voltage spikes (noise) can also cause disruption of the video signal every time a motor is running resulting in fuzzy lines on the LCD screen. 27

28 Camera Power Filter The camera filter consists of a Diode, an Inductor (ferrite ring with wire coiled around it), and a capacitor. The components are size to easily pass 12.6V DC while absorbing, like a sponge, any wild voltage spikes V From Power Source Diode Capacitor 12.6 V to Camera and LCD Inductor The camera power filter is included in the SeaMATE Camera Kit, that can be added to the Triggerfish or other ROVs and is also built into the new Pufferfish printed circuit board.

29 Wiring up Your Video System Looks pretty messy so lets look at it by systems 29

30 Wiring up Your Video System - POWER BOTH the Camera and the LCD Screen need power. The male power connectors are coming from the Camera power filter and one plugs into the camera connector and the other into the LCD connector. Male Power Connectors Camera Power Connections Solder black to black and red to red, cover each connection with heat shrink LCD Power Connection 30

31 Wiring up Your Video System - Video The yellow connector on the camera tether is the video signal and connects to the yellow connector on the LCD cord. Optional second camera, adapter maybe needed Be VERY CAREFUL plugging the black end of the LCD cord into the black connector on the LCD screen. Make sure you have the pins aligned correctly. They pins can be very easily bent.. Video from Camera Video to LCD Cord LCD Cord plugs into LCD Screen Blue wire on LCD cord is not needed Cover video connections with tape so they do not jiggle apart 31