Dumpster Dave's Frugal ATM Page
First some acknowledgements and pointers to some very important websites where most of my questions have been answered!
Search/Surf the ATM Archives and learn how to sign up on the ATM list.
For those interested in homemade go-to telescopes, see the Scope-Drive List and/or Scope-Drive Webring.
I started my ATM adventure by building a grinding machine and trepanning 6" and 13" blanks. The first 13" blank was hogged and polished to f5.2, but met demise at the wheels of a jogging stroller before I could figure it. Thoroughly depressed, I put everything down for about a year. I finally, trepanned another 13" blank and hogged and began polishing. Meanwhile, I only had my son's 4.5" Meade reflector to observe with and wanted to get out under the stars with something a bit larger. I caught an auction on eBay by chance and picked up a 16" x 1" thick plate glass f5.6 mirror from Obsidian Optics. I then began building the OTA to house the optics. It took a long time, but that scope is now functional. It closely mimics Mel Bartel's Tri-Dob. It is an absolute joy to use, cools down FAST and gives excellent images! I owe a great deal to the members of the ATM list for their patience, advice, webpages and help!
Because I started the adventure by building a grinding table it earns first entry on the ATM project page!
Grinding Machine Foucault Tester
(here's my slitless, moving source tester w/ mayonnaise jar lid handle)
16" Tri-Dob Version 1.0 Version 2.0
Commercial Optics...everything else homemade Commercial Optics...everything else re-made ;O)
Construction (v1.0) Construction (v2.0) SolidWorks (v2.0)
Homemade Laser Collimator Wooden Crayford
(Laser pointer and PVC tubing) (retired)
Binocular Mount Binocular Mounts (again)
(parallelogram style--Steve's Birthday) (building twins from scratch for a friend and myself)
6" f5.5 truss-tube reflector Copy scopes
(A rich field suitcase-portable with homebrew optics) (salvaged copy machine lenses assembled with cheap eyepieces & PVC tubing)
There was some discussion (summer of Y2K) on the ATM List regarding harvesting one's own pitch. I chimed in a few times. Since picking up the new hobby and making mirrors, I'd heard or read somewhere that one could cut corners by using pitch harvested from trees (i.e. conifer tree sap). Jon Fields' old website (which is now gone) was the only one I had bookmarked that had specific details on this process. He was kind enough to correspond with me on the subjects of pitch, grinding machines, and trepanning. He's a man after my own heart! Thanks Jon! At the VA in West LA I successfully harvested and used conifer tree sap nodules from 8 or 10 trees and used it to polish my homebrewed primary mirrors. The trees look like this:
...and the 13" mirror looks like this on the tester:
The insets are of a branch of the soft needles and a nodule of sap , just FYI.
The second image is a better picture of a nodule that's about 2" in diameter. The stuff smells wonderful when heated up!)
Miscellaneous files for download:
Dave's Scout Astronomy Merit Badge PowerPoint Presentation