Projects

Logitech Quick Cam 4000 adaptor. I purchased a QC 4000 some time ago but in order to use it I needed a 1.25 inch adaptor to replace the camera's lens assembly. I decided to try my hand at machining one myself. I started with a piece of 1.25 inch aluminum and drilled a hole through it and then turned one end down to fit the camera casing. After getting the camera end roughly turned down to size I bored the inside of the adaptor to size and then finished the camera end so that it made a snug fit into the camera casing. I then painted the inside with flat black enamel spray paint. Finally, the camera was reassembled.

Adaptor - 1.25 Inch Barrel End

Logitech Quick Cam 4000 adaptor. I purchased a QC 4000 some time ago but in order to use it I needed a 1.25 inch adaptor to replace the camera's lens assembly. I decided to try my hand at machining one myself. I started with a piece of 1.25 inch aluminum and drilled a hole through it and then turned one end down to fit the camera casing. After getting the camera end roughly turned down to size I bored the inside of the adaptor to size and then finished the camera end so that it made a snug fit into the camera casing. I then painted the inside with flat black enamel spray paint. Finally, the camera was reassembled.
Adaptor - 1.25 Inch Barrel End Larger Image	Adaptor - Camera End Larger Image	Finished Adaptor Larger Image
Adaptor Mounted in QC Casing Larger Image	Assembled QC - Front View Larger Image	Assembled QC - Side View Larger Image

Artificial Star Project. I decided to build an artificial star to help keep the optics of my Schmidt-Cassegrain collimated in order to improve the quality of my planetary images. Collimating during the valuable moments of good seeing is a waste of good observing so I set out to build the artificial star so that the collimation can be done during the day. I found a couple of Web site that explain how to build artificial stars. One uses a pin hole in aluminum foil while the other uses optic cable as the point light source. Pin Hole Light Source Fiber Optic Point Source I decided to go with a fiber optic design since I could keep the light source smaller than a pin hole. A smaller light source can be placed closer to the telescope. A 0.1 mm pin hole has to placed at a distance of 37 meters from an 8 inch telescope, which is too far away for our small back yard. In the article on the fiber optic design the author describes using a 62 micron cable, which still has to be placed at a distance of 23 meters. I decided to go with a smaller diameter fiber (9 micron), which can be placed at a distance of only 3.3 meters. The problem with a small fiber is getting enough light into it so that it is bright enough to be seen. I bought the brightest LED that Radio Shack sells (5000 MCD) and dug up some lenses out of my collection to focus the light of the LED onto one end of the 9 micron fiber that I bought off from eBay. I found an old darkroom enlarger lens that worked nicely as a collimator and another lens with a short focal length (~25 mm) that focused the collimated light onto the fiber. Now that I selected the optical components I set out to build supports for the LED, lenses, and fiber optic. All of these components were then housed in a box made of plywood. The base is 3/4 inch hardwood plywood. The ends are 3/8 inch plywood (pine), and the sides are 1/4 inch hardwood plywood. The component holders are made from 3/8 inch plywood and 1.5 inch aluminum angle.
Component Holders Larger Image	Top View Larger Image	Collimating Lens Larger Image
Illuminated Fiber Larger Image	Diffraction Pattern - Inside Focus $Diffraction Pattern - Inside Focus$ Larger Image	Diffraction Pattern - Outside Focus $Diffraction Pattern - Outside Focus$ Larger Image

Tripod and wedge for a classic Schmidt Cassegrain from the 1970's. I have an old Criterion Dynamax 8 inch SCT that I picked up through AstroMart. One of the problems with the Dynamax 8 is that it did not come with a tripod. Instead, it had two tiny legs that allowed you to set it up on a table top. I had started making a tripod many years ago (~ 30 years) for another telescope project that I never got back to. The tripod legs and head have been around gathering dust so I decided to finish off the tripod and add a wedge. This project kills two birds since the college where I teach astronomy classes also has a Criterion Dynamax 8 without a tripod. One of the more complex parts that I have made so far for this project is the threaded rod that connects the tripod and wedge. The rod is threaded on both ends and does not have any threads where it passes through the tripod head. As you can see from the photos it has an aluminum plate screwed to the base of the longer thread. This plate allows attachment to the bottom of the tripod head with wood screws. The threads were cut on my metal lathe and then finished off (deburred) with a hand die. The wedge that will hold the telescope can be seen on the bench behind the tripod in the first photo.
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The making of the hand nuts to hold the wedge and leg locker to the tripod. On the left is a finished nut. In the center is the threaded hub for the second nuts. Notice that the outside of the hub is knurled so that when it is pressed into the aluminum disk it is locked in place. On the right is the setup on the milling machine for cutting the notches in the aluminum disk.
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Here is the finished wedge. You can see that the latitude adjustments are made using locking screws and a pair of sliders. In the center image you can see the piano hinge that attaches the two plywood plates which make up the wedge. The plywood is 3/4 inch hardwood.
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On the left you can see how the aluminum blocks, which are part of the latitude adjusters are hold in place with four 1/4 inch screws. In the center you can see the leg locker and the other hand nut that holds it in place. On the right is a view of the wedge and tripod.
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Here is the Dynamax 8 on the tripod. I immediately noticed that the wedge will need some supports on the underside to take up vibrations. The last two pictures show the telescope on the modified wedge after the supporting frame was added. Some of the vibrations were reduced but it looks like the tripod legs need some additional work.
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Here is the support frame for the wedge that should take up much of the vibrations in the plywood. The plywood was much more flexible than I anticipated. The frame is made of one inch wide by 1/2 inch thick aircraft aluminum. The aluminum stock was cut to length and then the pieces were clamped together using picture frame clamps. While it was clamped together I drilled and pinned the pieces together in order to braze the aluminum together using special aluminum brazing rods. The ends of the pieces were beveled before brazing and carefully cleaned. A Mapp gas touch provided sufficient heat to bring the joints up to the 732 F temperature needed for the brazing rods. I initially tried a standard propane torch but it wasn't hot enough.
Larger Image Side view of the frame.	Larger Image One of the brazed joints.	Larger Image End view of the frame.
Larger Image Another end view of the frame.

Objective Prism Spectrograph designed to mount piggyback on my Meade 8" SCT. It can be used with my 35 mm OM1 or the Sac7 CCD camera. The last picture is a test of the setup using the OM1 and Polaroid 800ASA film with the Pleiades cluster. A four minute exposre captured a lot of spectra.
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Camera adapter that allows me to attach my Sac7 CCD camera to a 35 mm camera lens. The first picture shows one of the pieces being machined out of some aluminum scap material. The last image shows the adapter being fitted to the Sac7 camera, 90 mm lens and objective prism spectrograph.
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