So I made some improvement and upgrades to the chair. I added:
-Another, smaller aluminum strap that utilizes the same connection points as the spreader bar. This strap will be used to keep the chair in the stowed position.
This is genius. I tried to the same thing with an eye hook and latch but it is difficult to get the little hook onto and off of the little eye. I have a small piece of the aluminum bar left over. I am going to use it just like Speedy1985.
Some of the mods I made to the original design:
• Increased leg length to 4'. I would have had enough room to raise the seat high enough for my scope with the shorter legs but now I have a surprisingly comfortable back rest. I mainly "perch" on the seat when observing but from time to time it is nice to lean back and look at the sky naked eye and give the body and the eyes a break.
• Like Speedy, I put a pad on the seat. For this I used an old closed cell foam kneeling pad that is usually sold and intended for gardening. We still have another one so the spare will not be missed.
• Just by chance I had a bolt for the seat that was long enough AND was fully threaded. This turned out to be fortuitous as the threads bite into the back of the front leg just enough to keep the seat from slipping. I hadn't even noticed until now but you can see the bite marks in the back of the leg in the attached close-up photo. The fact that I used Doug Fir (a softwood commonly used for construction especially in the NW) and not hardwood helps give the bolt some bite. I have had zero slippage of the seat when in use.
• I also added a wider foot to the back leg. So far I have only used the chair on my concrete driveway but I anticipate using it on soft ground and this wider foot should help prevent the back leg sinking in.
• I cut out the bottom of the front foot. You can see this in the photo. This is in anticipation of use on rough, hard ground. (I have an idea of a dark site in the Olympic Mountains that will most likely be on an old logging road or loading area which are usually packed down hard.) Better for the outside edges to make contact and the inner part to bridge over for better balance.
• I used wood screws in lieu of glue and bolts mainly just because I had several partially used boxes left over from previous projects but over time they should provide a more rigid and less wobbly structure.
• The first time I used this chair, I had trouble with the aluminum bar not staying in place when I moved the chair around the scope. I fixed this but putting a wingnut on the end of a bolt. Fortunately, I already had two long bolts in my box of miscellaneous nuts and bolts.
I mainly used wood and hardware left over from other projects. I had to buy the hinge, handle, aluminum bar and eye and latch. I ended up spending $19.17 (before sales tax) so while not cost free, my tightwad nature is still pleased. It works good in the driveway and I hope it will work good when I travel to dark sites.