Various Projects That I Have Undertaken Over The Years
Barn Door Tracker.
While taking photographs of Comet NEOWISE C/2020 F3 it occurred to me that the ZWO ASI178 camera that I was using would make a good wide field camera for deep sky work. I found construction plans for a barn door tracker on Gary Seronik's website. Initial trials of the barn door tracker indicated that there was too much flexture in the motor shaft, which has an extension added to it due to the thicker plywood that I used. To overcome the flexture I added a support to the end of the motor shaft that allows me to insert a pin into the hollow end of the extension, which now keeps the small brass gear firmly in place. I also modified the procedure for bending the brass threaded drive rod by forming it with a plastic mallet over a piece of plywood cut out to a 7 inch radius. The following pictures show the completed barn door tracker. For polar alignment I found that opening the upper board while viewing Polaris on live video allows me to determine how good my polar alignment is. If the alignment is good Polaris will follow a small tight arc.
LXD650 RA Gear Repair.
One day I went to use my LXD650 mount and the RA motor would spin but the mount would not slew or track. I opened up the RA gearbox and found that one of the nylon gears was spinning on its pinion. To repair the gear I drilled a #60 hole in the pinion so that I could press fit a small piece of clock pinion wire that would engage slots that I cut into the nylon gear using a jewelers saw and needle files. The nylon gear was pressed over the piece of clock pinion wire, which does a good job of firmly holding the gear without any movement on the pinion shaft. When I pressed the aluminum spur gear back on the pinion it had a small amount of sideways movement on the shaft, which I resolved by putting a drop of super glue on the pinion when I pressed the spur gear in place. The RA gearbox has been performing well since the gear was repaired. The slewing and tracking are good. Considering the age of all of the LX200 classic mounts, which uses the same drive motors as the LXD650 mount, I am certain that others have or will experience similar failures. The tools and materials needed for this repair are a drill press, clock staking set, an assortment of clock pinion wire, a tube of super glue, jewelers saw, small vise, and very small needle files.
Tasco 10TE Refurbishing Project.
I received an old Tasco 10TE refractor as a gift that was in bad need of repair. The mount had a lot of paint chipped off from it, along with corrosion where the aluminum was exposed, and there were the remnants of a lot of mud dauber nests all over the telescope. The declination slow motion was broken, The counterweight shaft and counterweight were missing (threads for the shaft in the RA casting were stripped). The RA slow-motion cable was missing. The objective cover and dew shield were missing. The objective had a white residue between the lenses and the brass objective cell was cross-threaded into the steel adjustment ring. The tripod legs had lost a lot of their finish and several of the spacers on the adjustable legs were missing. Most of the chrome was also in bad shape. The repairs started with the objective by removing the retaining ring using a proper optical spanner wrench. It appears that someone in the past tried to remove it with a screwdriver and slipped resulting in a small chip to the surface of the rear lens. I cleaned both lenses (making sure to note the positions of the lines drawn along the edges of the lenses that mark their relative positions) and removed as much of the white residue that was between them that I could. I separated the brass cell from the adjustment ring by grasping the cell from the inside with the jaws of the 4 inch chuck on my lathe and grasped the adjustment ring and gently applied force until the ring came loose from the cell. Fortunately, the threads were not damaged. The finder scope was in just as bad of shape as the rest of the telescope. Its objective lens had been removed from the cell and replaced backwards and the crosshairs were broken off. To repair the broken declination casting I filed down the broken fork so that I had a flat surface and brazed a replacement fork onto the casting that I made from a piece of scrap aluminum plate. To replace the missing cross hair on the finder scope I removed the threaded ring that held the cross hairs and set it on top of an old two liter plastic bottle using double sided tape. New wires were set in place and held under tension with lead weights and then glued in place with 5-minute epoxy.
Refinished Rattan Chairs.
Our four rattan patio chairs were looking very rough (flaking paint and worn out upholstery) so I stripped the chairs down to the bare rattan using lots of paint stripper and lacquer thinner. The residue of the paint and stripper was removed by corn cob blasting the chairs (powdered corn cobs in place of sand with my sand blaster). Each chair was then sanded and then at least three coats of semi-gloss paint were applied with a sanding between each coat. After the paint had set for several weeks the chairs were sent off to be re-upholstered. Two of the chairs had to have the rattan strip, which the upholstery on the backs were stapled to, replaced due to dry rot and splitting. The replacement rattan poles had to be cut lengthwise with a bandsaw then they were steamed and then bent and nailed into place. C-clamps were applied to the new rattan until it were dry.
Folding Oak Table.
Folding oak laptop table that I made using pictures of a similar table that my brother-in-law has as a pattern.
Here is a miter gauge that I made for my router table. It is made from 3/8 inch aluminum plate, one inch aluminum bar stock for the T-bar, and one inch aluminum round stock for the knurled handle. The scale was ruled using my indexing table.
Laser Pointer Bracket.
Laser pointer bracket. I made a laser pointer bracket from a couple of platter spacers from an old hard drive, some nylon screws and a piece of 1/4 inch aluminum plate. The laser pointer is mounted on my eight inch Criterion Dynamax telescopes, which I use for public observing. Now when someone asks where the telescope is pointing I just turn on the laser pointer.
Tube rings for my eight inch rich field Newtonian. About a year and a half ago (July 2010) the mount for my eight inch rich field Newtonian fell over onto my car and then landed on the floor of the garage breaking the saddle that I had made many years ago not to mention leaving a basketball sized dent in my car's front right fender. These rings are made from two layers of 3/4 inch plywood. The plywood layers were glued and screwed together. I used a drum sanding attachment on my drill press to sand the insides of the rings to size and then stained and varnished them. The latch hardware was made using my metal lathe. The notches in the rings where the latch hardware is attached were cut on my router table. On my equipment page you can see the eight inch Newtonian with the old saddle, which consisted of a saddle made from oak with spring steel straps that held the tube in the saddle.
Flat Field Light Box and Carrying Case.
This light box was made from 1/4 inch foam core board that was glued together with hot glue. The 3/4 plywood base fits over the end of my Meade 8 inch SCT. There are four 12 volt bulbs inside the box that provide illumination. A sheet of 1/8 inch white plastic acts as the diffuser.
Filter wheel for my Watec 120N camera. After using the Watec 120N camera to capture some great deep sky black and white images I decided that I wanted to try using RGB filters with the camera. Since filter wheels can be rather expensive I decided to try my hand at making my own. I cut the filter wheels (two of them just in case I mess up on one of them) from 4 1/2 inch aluminum round stock and faced them off on my lathe. Then I bored a 3/8 inch center hole and turned the outside edge. Next came the holes for the filters using a 1 1/16 inch bimetallic hole saw from the local hardware store. The next step is to use the boring head on my mini-mill to enlarge the holes to 1 1/4 inch.
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.
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 sites 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.
I went 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.
Tripod and Wedge for Criterion Dynamax SCT.
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. 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.
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 one of the 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.
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.
On the left you can see how the aluminum blocks, which are part of the latitude adjusters are held 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.
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.
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.
Objective Prism Spectrograph.
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 two pictures are tests of the setup using the OM1 and Polaroid 800 ASA film with the Pleiades cluster (left) and the sword region of Orion (right). Notice in the Orion spectrum the nebular emission lines from M42.
35 MM Camera Lens Adapter.
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 scrap material. The last image shows the adapter being fitted to the Sac7 camera, 90 mm lens and objective prism spectrograph.
Stereo Viewer Card Holder.
Stereo viewer holder that I made to replace the lost holder from an antique stereo viewer that I purchased. I made it from walnut and brass. The spring-loaded piece on the bottom of the holder was made from sheet brass and the attached knob was turned on my watchmaker's lathe. The stereo card holders attached to the top were made from brass rods that were bent to shape and then fitted into holes in the walnut.
Clock hands that I made a number of years ago using a jeweler's saw. I laid out the pattern on a sheet of steel and then used the saw to cut out the hands and then filed the edges smooth. I gave the surfaces a brushed finish and then heat-treated them to give the hands a blue finish.