13" F/3 telescope build

[Mitch Alsup]

Well, I finally got the secondary properly positioned.

Here one can see (on the primary with tissue paper) that the secondary is perfectly centered over the focuser and perfectly pointing at the primary.
{You can tell this by the 2 dots beyond the line at all 4 corners) The second set of dots in the upper left is from a second sheet of tissue paper.

One can also see the primary is being hit in its center.

 

[Mitch Alsup]

At this point the focuser is pointing square at the secondary and the secondary is pointing at the center of the primary. But due to very small build errors, the primary is not pointing at the focuser.

So we make a couple of translations of the upper assembly (by lengthening pairs of poles equally. And Presto:

It is close enough do do fine collimation on stars themselves.

 

[Mitch Alsup]

I decided to change the "ground board" support to make the scope taller. I decided (this go around) to make the scope comfortable viewing at Zenith::

Thus, the "ground board" has become a "waist board".

 

[Neptune]

Love this scope. Ascetically pleasing to look at as well as to look through!

 

[StevSmar]

I decided to change the "ground board" support to make the scope taller.

I didn’t realize how short your scope was until I saw the photo in your post #73!

Are you happy with how your scope turned out?

I’ve just purchased a 10” dobsonian, can’t wait until winter has set in and puts an end to outdoor project season!

 

[Mitch Alsup]

I didn’t realize how short your scope was until I saw the photo in your post #73!

Are you happy with how your scope turned out?

Mostly.
When collimated the scope performs very well for entire astronomical trips. It is getting there that is the problem.
But I don't like using the truss tubes as a smith platform;
So, I am putting a normal set of collimation threaded-things on the mirror cell, and attaching the edge supports to the Y-frame so they move with collimation.

The shortness of the scope is a benefit.