**How To Calculate The
Column And Wall Height**

(Note: I like to keep things simple and effective, for me. There may be a better way to do this, but, for me, this is the way I did it. Totally based on the viewing height that is comfortable, for me.)

After trying various heights, this was the one I felt was best. The tripod legs fully collapsed and the scope at fifteen degrees which then defines the eyepiece height. .

I use my TeleVue Panoptic 41mm alot. So the basis for the final height was being able to look into the Finder Scope almost on my tiptoes and and the Panoptic was also at a very comfortable viewing height. It is the tallest of my eyepieces

Note: All my calcs are based with the telescope at fifteen degrees to the horizon. An arbitrary number that felt comfortable for me. After all, below that, the athmosphere really makes seeing anything very difficult.

Then, we level the scope tube.

Adust the degree wheel to zero. I marked the spot with tape. The cast in marker is really hard to see.

Then tilt the scope up fifteen degrees.

When it is this low, I want the angles to work out such I can keep my little trapdoor shut and the image will be above that and the door .will not get in the way of the image

I taped two State Fair yardsticks together. The six inch marker will be centered on the axis and, from that, the end of the yardsticks will be four feet from that center.

I start by lining up the six inch marker on the center of the Declination axis.

Then I note the end of the OTA falls on 33 1/4". Gotsta to remember this.

We then tape the yardsticks to the bottom of the scope so the 33 1/4" mark is at the end of the tube.

Later, I flipped the sticks on edge, not flat, to the scope. This yieleded a more accurate measure to the end of the yardsticks.

We need to measure how far the trapdoor comes up from the base of the dome

20" exactly.

Now, from this, we can calculate the wall height. Right?

Note: This is an earlier model dome and the newer ones may have a different dimension.

We make sure the tripod is level .

The height to the base of the wedge is 29 1/2". I used 30" for all my calcs.

The measure to the top of the trapdoor will be 63". I rounded that to 64" for good measure.

+++

Now, the math.

The top of the stick is the bottom of the OTA.

We need to make the Dome trapdoor 64" from the base of the deck for the fifteen degree test.

Knowing the height of the trapdoor is 20", this places the top of the Rings at 44".

64" minus 20" eqauls 44".

The Ring Assembly is 5 3/8" tall. I rounded this to 5".

The top of the wall then, will be 39".

44" minus 5" equals 39".

I am putting a one inch thick cedar deck lumber on the base of the wall. So, the wall has to be 38" tall.

64" minus the Trapdoor of 20", minus the ring height of 5", minus the 1" weatherproof deck lumber equals 38" for the wall panels.

Now, we are finally ready to chop some wood.