Dobsonian Telescope Scale




Introduction: Dobsonian Telescope Scale

Hi all!
I´ve been searching and ther´s almost nothing on the internet about how to make a homemade dobsonian telescope scale, so I decided to make one myself so all of you that have a dobsonian classic telescope can make one and improve your skills in astronomy.
This is very useful if you have some software that tells you the coordenates of altitude and azimuth.

Now let´s begin with this project:

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Step 1: Materials and Tools

For this project i used:

  Plastic for printing the scales.
  A dremel to cut out the holes and cut the circles.
  And some other tools to make the scales fit in good enough and to put the angles correctly.

So as you can see you don´t need much to make this scales.

Step 2: Printing Your Scale

Now, you need two scales one for altitude (up and down) and one for azimuth (left and right) so we need to print them in the type of materials of your chice, in my case I chose a kind of plastic that is strong and flexible.
I went to a store that printed all the things you want in a lot of materials.
Here is the link to a pdf for the scales of altitude and azimuth:

Or instead you can deraw it yourself =)

Step 3: Cutting It

Now that you have the scales printed is time to cut the circle out of the azimuth scale, my telescope has three points of support that make the telescope turn smoothly so i needed to cut off three circles on the scale so it could fit in the base. I did this putting some double face tape in the circles and then putting on the scale so i could cut them in the exact point.

With the altitude one I cut it like an arch and with a 90º ruler I move it till it fitted in good and glued it.

This step is the hardest one and it has to be made with very good exatitud so when you want to find a space object it  tells you the exact corrdenates.

Step 4: Making the Coordenates Indicators

This was very simple to do, very few materials and hot glue is all you need.

With the images below you will understand how i did them.

The wood pieces were 5cmx5cm and glued in together, one of them with a shape of a "u" so, as you can see, I put a pin in the center of the "u" so it tells me the degrees of the azimuth. This mechanism can be fitted in and out so it wont brake. This was made with three of 5x5cm peaces of wood.

The altitud indicator is also very simple, I did it with a piece of plastic that i didn´t cut and cut a hole in the end of it and glued another pin in the center. Cut a hole and put it in the screw that came with the telescope.

Now you have all in place it´s time to show you how to place it so that you can find all the space objects you want.

Step 5: Orientate the Telescope

So now that you have your telescope in place it´s time toorientate it. You have to put the 0º pointing to the north and the 180º pointing to south.
And in the altitude scale you have to have the 0º when the telescope is exactly horizontal and the 90º when the telescope is exactly vertical.

Now you can look to the coordinates of the objects you want to see.

Here are some videos with saturn and the moon taken from my dobsonian 10" telescope:

I hope that this instructable was useful to all of you, see you in another instructable!!
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    4 Discussions


    8 years ago on Introduction

    Nice job! I built a set last year and influenced three other members of my club (ASEM) to add them. I concur with Starry night. My pointers are magnetic. Calibration is as easy as
    1] Finding a star
    2] Getting its ALT/AZ coordinates from Starr Night
    3] The pointers are set accordingly.

    Here's a link to my "circles" (they are near the end of the page):


    8 years ago on Step 5

    I love the videos!

    Best Wishes.


    8 years ago on Introduction

    How you aquire alt-az coordinates for your target? Do you use a particular program ? did you write it yourself?


    Reply 8 years ago on Introduction

    I have a program called starry night that came with my telescope, is a quite good software to use and is my favourite. There are lots of these tipes of programs, also for phones. If you have an IPhone you´re lucky couse there are lots of apps that can help you.