Gosh! It has been since August 1998 that I wrote one of these. Well, I do what I can. Lots of progress to report. Mike and Dan are here and we are busy laying out the electronics board for the Mark V and lacing up the cables on the Mark IV prototype. When I get a couple of parts from the shop, I will be able to put together a full Mark IV.
Sigh! Since I started writing this, this has been done, and the full Mark IV is sitting here waiting to have all it's connections checked out. Everything is there, including two new cameras with most of the latest fixes.
I have put the first set of six parts into the shop for this run of Mark IVs. This is the inner axis parts. We can mount the electronics boards while Mike and Dan are here and then I will be able to finish them up when they are back in school.
A Mark V you say? Well, it is a single camera electronic system designed to search for asteroids. The goal is a nice cheap 2k camera system with everything in one box. The "box" at the moment is a standard PC case. We will just buy an overpowered case, and put the electronics and the cooling system in it. This will also be the system to send Grzegorz Pojmanski for use in the South at Los Campanas.
The first picture is a "first light" picture
for the Mark IV CCD442A camera. We had an earlier "first light" picture but it was made with the Ford chip and had lots of defects. This chip (Grade 4 - the lowest grade at $2000) looks pretty good. This is truly a first light picture. It was made with black tape over the CCD with pin holes in it. We are looking at the pin hole pattern. Just a picture taken off the computer monitor. I did not save a .fts image.
Next is
a first real picture.
It is of the end of the room. You can see my cat pendulum clock. The cat clock wags its tail, so the tail is always fuzzy. This is done in false color. Just an arbitrary mish mash of color.
Next is
the end of the room in shades of red.
I have put up the eye chart next to the cat clock. You can't see it here, but this picture is on the CD ROM that I distributed and the CCD camera is 20- 20.
The end of October saw the lenses arrive.
This is a picture of
the south end of a north pointing V filter lens .
And this is the business end of the lens.
The stapler is there for size comparison.
During November I took the system apart many times. During one such
effort, I took a series of pictures.
First is the RA axis.
The bearing shaft can be seen at the lower left. The bearings are in the two horizontal bars. You can think of this as a German equitorial mount with a telescope on each side of the declination axis instead of a weight on one side. I am prepared to be corrected on my terminology. The RA bearing consists of a 3/4" SS shaft mounted in ball bearings. At the upper right you can see the declination axis. This is a 3/8" shaft. I would like to have made it heavier, but it was a question of finding all the right parts. The declination drive motor sticks up at the top.
In the next picture
I have started to hang
the parts for the telescope tube cage
on the declination mount.
The bottom mount parts are there and one of the focus motors has been mounted.
In the next picture
the top of the cage and the break disk
have been mounted.
The idea of the brake disk is to get something at a large radius to clamp to on the declination axis.
In the next picture
the top cage pieces and the lens hanger plates have been added.
In the final version, these are just oversize to the lens tubes, and the lens tubes are held in place with tie wraps. (Sigh! but not for the first 6 systems. By mistake the lens mounting plates were ordered with the wrong drawing, so again they will not be quite the right size.)
The lenses are shown mounted in this picture.
The V lens is on the right and has a red tint from the coating. The I lens is on the left and shows a blue tint. Possibly this will not show up very well when scanned.
The printed circuit boards for the electronics are added next.
There are 4 boards in the four possible spaces. I have now designed covers so that the electronics will not be so exposed.
The trombone focus mount for the camera is shown here.
The camera is mounted from the back. Care is taken to machine the bar that supports the camera so that the 3/8" SS shafts are perpendicular to the mounting face. The CCD is mounted to the TEC which is mounted to this same face. If all the glue joints are thin enough, then the CCD will be perpendicular to the trombone shafts. The general scheme is to design the parts as a trapezoid so that even if the sides are not square, the axis of the lens is still perpendicular to the CCD.
This picture shows
a Norman Molhant-style flat field box.
There are several green LEDs at the far end, and three layers of screens inside to try to achieve uniform lighting. We shall see.
Here I am out on the porch getting the Mark IV hooked up.
At this point only one camera is working. You can see one of the lens tubes in front of my hands with factory paper covers on each end to keep it clean. There are wires hanging off everywhere. As I type, Dan is busy tying up all the wires to make it neat.
The next picture is taken looking down on the Mark IV
which is on the porch off my bedroom on the second floor. The roof is over my front porch. The picture was taken from the third floor deck which will be its final home in "Dead Barney". Both lens shades are in place for the picture. This shows the size of a Mark IV installation. The whole system is sitting on a tea cart.
Finally, an early image from the Mark IV
as read into "Image Scientist". Note the two stars. Some improvement in focus is needed.