Jump to content
  • Join the online East Midlands astronomy club today!

    With active forums, two dark sites and a knowledgeable membership, East Midlands Stargazers has something for everyone.

My dobsonian


Recommended Posts

Well I had a go at collimating my 12" Orion Optics dob last night. The first thing I did was check to see if the secondary holder was central, it wasn't. So I started messing with the adjustment screws and ended up taking the whole spider assembly out to get a better look at how the secondary was mounted and how it moved with the adjustment screws. It was at this point I noticed the wires. There is a double electrical wire going into the cylindrical central section behind the secondary mirror that the spider vanes connect to. Anyone have any idea what these might be for?

Anyway I put it all back together and lined everything up and when I had finished it all looked more concentric through the focus see tube than it did before. Miraculously I open the front door and actually saw a few of the Plough stars through a hole in the cloud so I quickly got the scope on the drive and an eyepiece in. With the scope at room temperature and a reasonable magnification the stars were not pin sharp but everything looked symmetrical. After about 10 mins the clouds closed in and I packed away but I'm sure the stars looked more focused and sharper after 10 mins of scope cooling.

Now I need a clear and free evening for a proper test!

Link to comment
Share on other sites

I would agree that it looks like a dew heater, built into the stem. Check it with a multi meter, if it has some continuity, without shorting to the body, it may be worth connecting it.

A secondary heater on a newt is just whats needed. 

If you get stuck, bring it over, I'll have a look for you. PM me if you need help.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.