For the first time in this project, I went to a class with no progress from the previous session. Thanks to a busy study schedule, I’d managed to do absolutely no work whatsoever on my mirror. A side effect of the week’s inactivity was that I found the work more strenuous than usual – I haven’t had such back pain after an afternoon’s grinding since my very first day. I either need to spend more time grinding glass, or get … Continue reading →
First of all, apologies for the late update. On a whim, I decided to replace Windows 7 with FreeBSD Unix on my PC, and have spent the last few days getting all my software installed, and the environment tweaked exactly the way I like it. It’s looking good. I have to say, I’m impressed – the KDE window manager has moved a very long way since I last used FreeBSD as a desktop operating system 7 years ago. Saturday I … Continue reading →
As I’ve probably mentioned in previous updates, I’ve given myself a schedule that compromises between the recommendations of the ATM class and the realities of my own busy life: I attend every second class. Today was to be a class day for me, except that my three year old daughter woke up with a fever, a sore throat, and no voice. The earliest doctor’s appointment we could arrange was bang in the middle of the class, so I couldn’t make it. I figure I’ll … Continue reading →
Last night I was feeling impatient to know my progress, so performed two basic tests on my mirror. The first test is described by Scientific American’s Amateur Telescope Making as the “Pencil Test”, but has many other names depending on the item of stationery used. This test determines how close the mirror is to a spherical surface by showing visually how close the mirror and tool are to being totally in contact. It’s very easy: I took a permanent marker and drew … Continue reading →
I just spent 2 hours (and about half an hour several nights ago) working with the next finer grade grit: #120 carborundum. It’s quite a different experience. The noise is higher pitched and much quieter, there is less friction, the grit takes longer to break down so each wet lasts longer, and the grit feels much finer to my fingertips when I spread it on the tool. Since I’m close to my target focal length, I’ve switched to 1/3 diameter strokes … Continue reading →
