Introduction:
The Philips Toucam and Vesta series of webcams have provided many highly detailed images of planets over time. The new Logitech Fusion Webcam has some interesting specifications and features that may provide improvements for planetary, lunar and solar imaging. See the links to other pages above that will be added as I test the Fusion for astro-imaging. The Fusion is widely available at many retailers including Walmart and also online and priced between $75 and $90. I recently purchased an OEM package of the Fusion for $55.
Conversion:
The easiest way to convert a webcam for telescope use is by purchasing a 1.25 inch adapter that can be screwed into the webcam, after the webcam's lens is unscrewed. Unfortunately, at the time of this writing, there is no commercially available adapter for the Logitech Fusion. The adaptors that are available use the standard micro video M12 X 0.5 mount thread, which is a larger diameter than that of the Fusion lens. You can see a comparison of the Fusion lens thread and the standard M12 X 0.5 thread (Vesta) HERE.
Luckily, Logitech has made it very easy to take the Fusion apart. Fortunately, the Fusion's circuit board fits perfectly in a plastic project box readily available from RadioShack. The T-thread from any camera T-ring can be mounted on the project box along with a T-thread to 1.25 inch adapter and the Fusion is ready for telescope use in any focuser.
USB 2.0 Cable:
The Fusion does have the advantage of having a high speed USB 2.0 interface. The USB cable that comes with the Fusion is six feet long. If this cable length will suit your telescope setup, you can omit the steps below that explain replacement of the USB cable. I use a 20 inch f/4.5 scope for planetary imaging and need a longer USB cable, so in the instructions I detail how to replace the six foot USB cable with a heavier-duty sixteen foot cable. A high quality USB cable is recommended for the replacement.
Tools:
Very simple tools are needed: Jeweler's screwdriver, razor knife, drill, small drill bit and hot glue gun. Superglue and black paint.
Parts used:
RadioShack Project Enclosure Part No. 270-1802 4"x2"x1": $2.69
RadioShack 10mm Insulated Standoffs Part No. 276-1381 Package of four: $2.79
Optional: 16 foot High Speed USB 2.0 Cable - Walmart - $11.97
Camera T-ring: $10 to $20
T-ring to 1.25" adapter: $12
Nylon washer and tie wrap.
Let's Start:
Opening the camera will void your Logitech warranty and you may ruin your webcam. Proceed at your own risk; I am not responsible for any damage to your webcam. That said.......the webcam is very easy to open and you're just mounting it in a plastic box.
Step 1. Remove two screws as shown:
Step 2. The two screws removed in step one will allow you to lift and remove the cover on the opposite side with a small driver:
Step 3. Remove four screws as shown:
Step 4. Remove center screw as shown:
Step 5. Lift the two metal hinges:
Step 6. Remove the plastic part and two screws as shown:
Step 7: Separate the webcam housing and remove the plastic switch cover as shown:
Step 8. Slide metal clip off USB cable:
Step 9. Remove screw that mounts circuit board to housing:
Step 10. Lift circuit board off plastic post. I used an IC chip puller to wiggle the board a bit while lifting it off the post.
The following Steps 11 through 15 are optional. They detail replacing the original 6 foot USB 2.0 cable with a 16 foot USB 2.0 cable. If you are not replacing the USB cable, skip to Step 16.
Step 11. Use small driver to slide open USB cable connector and remove the original webcam lens by unscrewing it from its mount:
Step 12. Remove the cable ground from the circuit board by applying a soldering iron on the opposite side of the point shown here:
Step 13. As heat is applied with the soldering iron, gently pull off the USB cable:
Step 14. Cut off the white plastic USB connector from the original USB cable allowing enough wire for splicing to the new USB cable. The wires are color coded. I used shrink wrap over the soldered connection splices. Black electrical tape would work as a substitute. Make sure the ground shield is long enough to reach the ground point on the circuit board.
Step 15. Resolder the new cable shield ground to the ground point on the circuit board and reconnect the USB cable connector. Place electrical tape to secure and insulate the connections. This is a good time to test the camera's operation with your computer, either with or without the lens installed.
Step 16. Paint the two LED lights with black paint to avoid any stray light inside the camera.
Step 17. Drill a hole for the imaging chip as shown. It can be enlarged to a size just large enough for reinstalling the original webcam lens if you want. When unscrewing the webcam lens, be careful the lens housing that remains on the circuit board stays affixed securely to the circuit board.
Step 18. The circuit board fits very well inside the plastic enclosure. To help hold the circuit board in the center of the project box, superglue two RadioShack standoffs as shown. The standoffs are the exact length needed to serve as holddown posts. Superglue two foam cubes in the position shown to help support the circuit board. Note that the positions shown for the foam cubes avoid contact with circuit board elements.
Step 19. Cut a large nylon washer in four pieces. Drill a hole in the end of two pieces and screw into the two standoffs as shown below. The nylon washer pieces can be rotated over the circuit board to hold the circuit board in place. Note that the nylon washer pieces hold down the circuit board on areas that have no circuit elements. Check alignment of the imaging chip with the hole in the housing and tighten both screws to secure the circuit board in this position.
Step 20. To better secure the circuit board add a glob of hot glue here:
Step 21. Remove the T-thread from a standard camera T-ring by loosening the small set screws.
Step 22. I made a small template to help center the T-thread around the imaging chip. Superglue the T-ring to the project enclosure.
Step 23. With a razor knife, cut a slot in the side of the plastic enclosure for the USB cable. (If you kept the original USB cable, the slot will be smaller. If you did not desolder the USB cable from the circuit board, you will need to cut the original webcam housing to remove it from the cable.)
Step 24. Drill some holes in the enclosure for cooling. (Another option would be to mount a small 5V fan powered via the USB cable - not done here.)
Step 25. If you kept the original cable, you could use the original strain relief. For my 16 foot replacement cable I made a strain relief by placing a tie wrap on the USB cable and hot gluing the tie wrap around the inside of the project enclosure as shown.
Step 26. Close up the project enclosure and install the four enclosure screws. I added another strain relief by attaching a tie wrap tag (green) to the USB cable and enclosure as shown. This is the completed camera with the T-thread to 1.25 inch adapter installed.
Finished!
If you completed the modification and would like to let me know how it went for you, you can contact me at the following email address:
Todd Freund modified a Fusion and his recommendations on the above procedure are HERE.