Hello ! This is my first time when I post a message on this group. I`m planning to build a 8 inch telescope and for this reason I intend to purchase a mirror, ...
Hi Ken, Group, I thought I would check in and say hello. In the last year or so I have became familiar with a different Yahoo site and have discovered the ease...
Hello, A few years ago I bought a 6 inch f/8 mirror from Orion and it is a very fine, sharp mirror. It shows straight Ronchi lines to the edge, splits Epsilon...
Jim, I took a quick look at your pictures. I'm not sure what the gear pictures are all about, but the craftmanship is impressive! The other set of pictures...
... Hi Bill, Sorry about that. I assumed the folks here were a subset of the regular ATM list. I'll paste in some explanations for you. Regarding the...
... Oops, ... Minolta 50mm (or 55?) from pawn shop. ... Small screw driver and spanner wrench. ... Lathe and a couple of pieces of round stock. The larger...
... so ... folks ... Welcome to ATM_FREE! ... does ... like ... let ... This Group would not be a GROUP without it's members. I saw the post the other day and...
Hello Jim, Thanks for sharing your pictures of the antibacklash drive. What kind of periodic error does the antibacklash spur gear final drive have? Don...
Hi Don, ... It's been 12 or 13 years since I've used that mount, but it seems that when the thing was tuned up well, the major error was on the order of 1...
... The old C8's actually had an antibacklash spur gear drive. Two motors were used. Each motor had a pinion drive gear. Don't know what the PE was. IIR, there...
TWO BLANKS, A JUG OF HOOCH, AND M-O-M OK, it wasn't a bottle of hooch, it was a 12-pack of Coke. But, between 11:00 a.m. yesterday and about 12:30 this...
Hi Again Don, I like that cable drive of yours. Very nice. :) ... Yep. Been there done that (on a smaller scale). A very large one would be an "interesting"...
Hi Guys... I have added a Spherometer Spreadsheet to the files area and some photo's of some of my spherometers to the photo's area in my folder. Check them...
Richard, is there a commonly accepted maximum value for span? Using your 4.5m as maximum, then the largest mirror that is do-able with 1" glass is around 14"....
When I stated a maximum span, I intended that as a maximum for MY level of skill as an optician... and my level of skill is nothing to brag about. Obvously,...
Greetings: I've uploaded four pics of my finished 8-inch Dob to the ATM-Free Yahoo! group photos area, in the directory "MTBurr scope pics". Comments welcome. ...
Micheal for whatever its worth, I make my "tool" as follows: The material is Por-stone (aluminite cement,about the strongest concrete around, it is 100%...
Thanks. I'm pretty happy with it. It still needs some tweaking, but it works surprisingly well. Thanks again, MTB ... From: Rick To: atm_free@yahoogroups.com ...
Hi Peter. So you brush the glue onto the tool? When you put the tool onto the tiles does the glue drip down onto the tiles? After you place the tool on the...
You did your tool all wrong! You are supposed to use lots of epoxy, and you are supposed to seal it with varathane to keep out the water. Then clamp your...
FWIW, after you have embedded the tiles, and the channels cleared with the carbo stone, make sure you bevel any tiles you snipped to make a circle. Just like...
You are almost right. I differ with you on hitting the mirror with a hammer. I would burn the grits off of it with the torch! However, oxyacetylene works...
Greetings: The Minnesota Astronomical Society (MAS) (www.mnastro.org) has launched an effort to acquire a big-aperture Dobsonian telescope (i.e., 30" or...
There will be no friday night chat in wanna be,s this week. saturday nite chat will be at: http://groups.yahoo.com/group/AAAAstronomy/ this chat will start at...
Hi all, I'm sure aluminum tubes are the best choice for truss tubes. But has anyone used EMT conduit instead? My local Lowe's, Home Depot, etc. doesn't stock...
On the bright side about EMT.. it won't rust, unless you take the galvanized layer off. (on the down side, the galvanized coating isn't easy to get most paints...
Hi Randal, I'm using 1/2" EMT for the trusses on my 8" bino-scope. Other than weighing a bit more than Al, they seem to work just fine :) For each OTA on the...
