The observing chair
One thing about being an amateur astronomer is getting to see what is in the night sky comfortably enough to be able to really enjoy looking. With the eyepiece of an f5 Newtonian telescope being anywhere between 900mm to 2100mm and more off the ground, on a HEQ5 equatorial mount it takes some gymnastics to be able to reach it, not to mention a step up on the odd occasion.
Enter the observing chair.
I found a number of designs for such a chair on the Internet, especially from amateurs across the pond but was also pleased to see that Sky at Night magazine had published a plan for such a chair here in the UK. Whilst designs are varied they break down into two main types. The first has notched rails. The second relies on friction to hold the seat in place. Within these two types are a number of variations.
I could of course have purchased a chair but where is the fun in that?!!
So one day whilst cleaning out the garage I came across some old shelves which had not been used for over ten years they were 20mm thick and in good order. Just right for a new role in life. Out comes the old circular saw - ooh those teeth are not in good shape! Where's the saw file? After a bit of work touching them up they are ready to cut.
Two shelves are selected and ripped down into equal width pieces to make the rails and rear support legs. The third is tidied up to form the back of the chair. The rails are clamped together and the position of the notches marked. These are then drilled with a 25mm spade bit whilst still clamped together. Not the cleanest holes in the pine I was using but go carefully and minimise tear-outs. Rails and chair back are screwed together and the rear legs assembled. They pivot on a pair of coach bolts with penny washers for packing. Add a safety bar to stop the legs from spreading and depositing me on the ground. Then make the seat.
Screws were recycled from some kitchen units when we refitted the kitchen and the bar forming the pivot for the safety bar came from an old printer.
Carrying the chair to its intended spot was going to be a bit of a problem unless done carefully. The back legs had a habit of dropping out and so I made a small wooden twist catch to stop that happening.
The chair has since undergone a few revisions one of which is to redesign the seat to enable it to fold against the chair back when not in use. This also makes it easy to transport as I simply have to hold the bar under the seat and it will lock into place. The original seat box has been repurposed to form a footbox. Once at the telescope the chair is most comfortable and enables me to spend more time looking at what is in the sky.