Re: [bigdob] maybe off topic homemade mirror issue
> I made a 8 inch f5.7 mirror and i have build the ota now i just needThere are many ways of doing this. One simple method is to cut out a
> to put a dot/small circle on my mirror. How the heck do i do this and
> be accurate ? please any procedures that you do will be fine ..any and
> all types of procedures welcome..I dont car just as long as it works
> and does not damage the mirror..thanks for all your help......Lou
paper circle the diameter of your mirror. Fold it in half on two
different diameters to find the center point. Punch a small hole
there, then use the paper as a template to mark the center of the
mirror using a filt-tip pen.
People use many things for the center mark. Some reasonable choices
are a square of electrical tape or a hole reinforcing ring. If you
use a laser for collimation, you will need to use a ring, so that the
center of the mirror remains reflective.
No matter what you use, it won't affect the mirror optically, because
the center dot is in the shadow of the secondary on a Newtonian.
- Take a piece of paper, set your mirror on it and trace
around it, cut the circle out, fold it in half then
fold in half again, cut a small piece off the pointed
end, open it up, place on mirror the hole is the
center of your mirror, mark as you desire,
I just used a permanent marker.
my astronomy & a.t.m. site
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- I've used the thin white tissue paper used for wrapping. The white
paper that usually comes inside Xmas presents such as clothing works
great for this. It is realitivly lint free, does not scratch easily,
doesn't stretch and can be folded to a fine point so when you cut
off the point you get a nice small 1/16" dia. hole. It can be had at
almost any store that sells boxes and wrapping for presents.
-- In firstname.lastname@example.org, Rick M <optical_stargazer@...> wrote:
> Take a piece of paper, set your mirror on it and trace
> around it, cut the circle out, fold it in half then
> fold in half again, cut a small piece off the pointed
> end, open it up, place on mirror the hole is the
> center of your mirror, mark as you desire,
> I just used a permanent marker.
> Rick M
> my astronomy & a.t.m. site
> Do You Yahoo!?
> Tired of spam? Yahoo! Mail has the best spam protection around