The whole point of this project is to reduce the weight of the telescope, and to do that all parts were re-examined to see if they were really needed. This is, therefore, by necessity a minimalist telescope. This is stricktly my design, but the idea is not new. I am indebted the inspiration and encouragement of Ross Sackett who makes beautiful telescopes” http://www.stardazed.com/":http://www.stardazed.com/
I got a little more done today, I cut the oblong holes in the mirror box that mount it to the boot. I was really worried that it would mate correctly, but careful (paranoid) measuring won the day. But it got too dang hot out there again. I can’t work above 91 degrees!!! So I took the parts out in the yard where I could take some better pictures. (We all like pictures, right?)
The three armed thing in the middle is the “base board”. On each arm will rest a small washer of teflon, and in the center a pivot bolt bronze bearing. On this turns the big round part, the “rocker box” shown at the left. The two of these give the telescope its back and forth movement. Under the rocker box is a sheet of formica. It has the property of being very slick when mated with the three teflon washers. The carcass at the right is the bottom of the “Optical Tube Assembly” or OTA. It is tradition to call it that, but because ‘open’ design telescopes like this no longer use big bulky tubes, its a little dated I suppose. I will be supporting the eyepiece on a small aluminum tube later on, but it’s not the same idea.
and then placing the OTA on top of that. There will be a bold to pivot on the OTA on at the top of the post on the left.
That give the telescope its up and down motion. Between the two of them I can aim the telescope at any point in the sky.
These next photos show it tilted at around 45 degrees from vertical. Of course, right now, I don’t have the altitude pivot bolt in place, so I have it clamped for the photos.
This shows the crescent horn clamped to the octagonal mirror box. It rides in its trunnion bearing. The pivot point is in mid-air, and in line with where the pivot bolt will be near the upper orange clamp on the right. Right now, the crescent horn is rough cut. I will be cutting it exactly to the right diameter with a router later on using a circle jig. It will be covered with formica too, and the trunnion that it rides in will have two teflon squares that will mate with it. The motion will hopefully be silky smooth. The OTA will be balanced so that whereever I point it, it will stay there. This is of extreme importance, and one of the reasons it has take so long to design this
The crescent will have several round holes cut in it to make it lighter without sacrificing its strength. I’ll show those pictures when I do it. In the mean time here are several more views from different angles.
This shows the ‘boot’ bolted to the mirror box assembly. The bolt in the middle of the box is used for adjusting the alignment of the optics. Its made from shoulder bolts, brass tubing, threaded rod and JB Weld. JB Weld is your friend.
If there mirror were there, this shot would be looking face on to it. There will be a nice 3/8” thick ring on top of the box later, and a 1/4” cover to keep the dust and dew off of it on hinges on top of that.
Next steps are to cut the top ring for the box, and then do the final shaping of the horn and other parts.
But first, I am going to Tybee Island Georgia, near Savannah for a few days vacation and dipping my feet in the ocean… yeaaahhh.
-- Telescope Maker, Woodworker, Brewer, Gizmologist, Gardner, Lawn Mower