Level Your Dobsonian Base Accurately in under 30 Seconds

[Jim L]

Many beginning amateur astronomers will purchase a Donsonian as their first telescope, and it’s an excellent and extremely cost effective choice. Part of Dob ownership includes learning about collimating and cooling the mirrors, improving the primary mirror cell, cleaning the mirrors, and a bunch more, but that’s all part of the experience and with the right tools, knowledge, and attitude, it can add to the enjoyment of owning and observing with your Dob. I’m going to talk about something else that’s just as important as those other activities, but that is much, much, easier.

You already know from the title that this thread is about leveling your Dob base, but why is it important to do so? It’s important because if your base isn’t level your telescope may, with assistance from gravity, swing on its own accord away from your target. This can be frustrating because first off you expect the scope to stay where you point it, and when it doesn’t that’s not good. Secondly, you may try to compensate for this behavior by adding in additional friction, but too much friction can make tracking erratic; also, not good.

Enough intro, here’s what you’ll need:

You’ll need two easily obtained and relatively inexpensive items; a bubble level and a leveling wedge. I went fancy with my bubble level, but I recommend something less fancy like this because large enough and sensitive enough without being too sensitive:

https://www.amazon.com/dp/B08ZYKKYY3/?coliid=I17ZPQ49GZF5C6&colid=3DKYFKLVLPA3S&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it
 

I also went fancy with the wedge, which is really a door stop, and it looks like this:

https://www.amazon.com/gp/product/B01F6KSDZW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
 

This particular door stop is worth the extravagance because its concave top won’t slip out from under your Dob’s foot, and it’s large enough to accommodate most reasonable slopes. Splurge - you’ll be glad you did.

Also helpful to mark the location of the three feet under your Dob are these small self-adhesive dots:

https://www.amazon.com/gp/product/B000BMBU9M/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
 

Let’s level!

Here you see the base plopped down on a fairly steep slope, probably four or five degrees or more. My bubble level is affixed to the top of the Dob base with strong double sided tape so I don’t forget it and leave it behind at the end of a long night’s observing. Note that the alignment line on the level is aligned with the dot on the base, and is also aligned with the center of the base, which is out of view. Also note the location of the bubble at the top, and a bit to the right of, the alignment line.

 

Here’s a lower angle view. Note the yellow dot in the bottom half of the base; it marks the location of one of the three short feet under the base.

Here’s the trickiest part because there are two steps. First, align the two dots. Next, and while keeping the two dots aligned together, rotate the Dob base in place until the bubble is split by the alignment line on the bubble level. When you’re done it should look like this:

 

All that is left is to slide your wedge under the foot of the base located below the yellow dot to bring the bubble into the center of your level, as shown. Your base is now level.

 

Without rushing I can easily level the base in way under half a minute. The result is a scope that locates and tracks objects easily, and that stays where it’s pointed. Good luck!

 

 

Edited April 19 by Jim L

[Richard N]

Curiously I have never found the need to level my dob. And indeed that’s what I perceive as one of its advantages. Each to his/her own I guess. 

[Jules Tohpipi]

11 minutes ago, Richard N said:

Curiously I have never found the need to level my dob. And indeed that’s what I perceive as one of its advantages. Each to his/her own I guess. 

Quite handy if you have a Goto dob or using an inclinometer😀

Edited April 20 by Jules Tohpipi

[saac]

17 minutes ago, Richard N said:

Curiously I have never found the need to level my dob. And indeed that’s what I perceive as one of its advantages. Each to his/her own I guess. 

It's important if you are using setting circles. 

Jim 

[Richard N]

9 minutes ago, saac said:

It's important if you are using setting circles. 

Jim 

Indeed - but as with levelling I find those to be an unnecessary level of complexity. Each to their own as I said. 

[saac]

No

1 minute ago, Richard N said:

Indeed - but as with levelling I find those to be an unnecessary level of complexity. Each to their own as I said. 

It is good that there are so many alternative approaches to suit different needs  

Jim 

[Alan White]

That is a nice repeatable and simple way of doing this, thank you for taking the time to share it.

I have rarely needed to level my Dobson over the years, but that’s driven by observing from level or close to level locations,
however with your method a simple option is now available.

Clearly I have been fortunate in my sites for Dobson use, however with a tripod I am more blasé about site as it’s easy to level.

 

Edited April 21 by Alan White