After putting up with a step stool as my observing chair for the first few months after re-entering the world of astronomy I decided that I needed something more height adjustable and portable. It always seemed that neither of the two steps was ever at the right height to make for comfortable observing and it always seemed that the stool was more of hindrance, overall.
There are loads of designs on the net for building your own observing chair and lots of suppliers that will sell you one but most of them either were designed such that they would be difficult to fit into my Mini Cooper or cost more than I was willing to pay. With a few I even had concerns about the chair portion staying where it was put.
Then I ran across the Home Built Astronomy Projects website and an observing stool design by Rod Nabholz at http://www.homebuiltastronomy.com/stool/ that looked like it would work perfectly.
It’s a very simple design made from eight 2×4 sections, a large bolt with a 1/2″ head, a length of 1/2″ pipe and pipe flange, some vinyl, foam and a few screws.
Because of my tendency to hoard materials while pursuing multiple hobbies I already had all the materials I needed and one night in December I spent a couple of hours to put the stool together. The result is the stool shown below.
While it’s been stained, I won’t say that it’s been “finished” as it was not only put together as a proof of concept but I also knew it would get dirty and so used a dark stain to hide its roughness as much as possible. It’s ugly but it turned out that it worked better than I expected and so the POC has become my workhorse observing stool.
A close-up view shows the holes in the side that allow me to adjust the height of the seat using the lag bolt as well as the handle that makes it easier to carry around and move.
The seat comes completely out of the base for packing into the car and the pipe can be unscrewed for maximum portability.
The flange is simply screwed to the center of the seat which I cut square for convenience. I already have plenty of plywood around the house and didn’t want to go out to purchase a circular piece of wood or take the time to cut one myself. A couple of minutes with the table saw and I had a serviceable seat.
I covered the top with pillow foam for cushioning and cut a piece of vinyl so that it was several inches larger than the seat, folded the excess over and nailed it down.
I decided early on that I would need to make at least one basic modification to the design that Rod published and that was with the way the legs were attached. Rod created his stool so the legs were permanently attached and fixed in position but since I need the stool to be collapsible I made it so that the legs were screwed on with a single screw at a point where they could be hinged up. When the legs are down, they’re firmly fastened in place with a single lag bolt.
As the legs are collapsed I just slip the bolt into an available hole in the side for storage.
There’s a tiny bit of play when the legs are extended since the hinge screws tend to shift as the legs are rotated. One change I intend to make soon is to replace the hinge screw with another bolt so that I can more completely tighten the leg against the base and eliminate that play. For the moment it’s a minor annoyance.
You’ll no doubt have noticed that there are only three legs. I did this to minimize the number of things to trip over in the dark. When using the stool I orient it so that one leg is aimed toward the scope since that gives me a more stable base when leaning forward to look through the eyepiece.
I had some stain left over from previous projects so literally just slapped it on. I wanted to give the wood some protection from the elements but didn’t feel a need to go overboard since I knew I’d be using the stool in all kinds of dirty conditions. If it started ugly, I wouldn’t care how it looked after a few years of use.
It won’t win any design awards but it went together quickly, cost next to nothing and has worked very well so far.