I - Base assembly

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base plate The base assembly consists of 4 pieces of 3/4" plywood. There is a base (A), 2 roughly triangular uprights (B) and the tilted platform (C). The angle depends on where you live, so you will have to modify the dimensions in the drawings to suit your location. I live at 36° North, so I use this angle. Look up the angle for your location by following the directions in the sidebar. I use glue and drywall screws to put the base pieces together. The slanted piece also gets 2 strips of metal (D), cut from the same stuff as piece (xxx) described below.

How to find your longitude and latitude
Of course you can do it the old-fashioned way and look in an atlas, but since you are sitting in front of the screen, you can do this:
1: Go to mapsonus.com
2: Once there, click on MAPS
3: Fill in your address, and get the map
4: Below the map, there is an option "Map-Clicking will..", and there you choose the option "Show Lat/Long"
5: Now click on the map, and you got your coordinates!
upright panels
slanted panel You need to be able to precisely level the base. This is done with a bubble level glued to the base plate, and using the 3 adjustable feet. At the local hobby store I bought some 1.5" toy wheels. These are made out of maple, and have holes in them just big enough for a 5/16" bolt. Take 3 5/16"×3" carriage bolts, and cut a relief in one side of the wheel for the square collar. Add a nut and you have a knob. We will use this design for all knobs on the sunspotter. The ones you just made stick through holes in which you tap 'T-nuts'. Alternatively you can use a small chisel or knife to cut a hexagonal space for a 5/16" nut in the underside of the plywood base. On the end of the carriage bolts, file a knob that fits into the felt feet. These are the kind that have felt pad on the bottom, a plastic support disc and a 5/16" thin metal cylinder sticking up. Normally, you hammer the cylinder into the 5/16" hole that you find in the bottom of chair legs (at least the ones made for the American market). Our bolts fit into these cylinders. To prevent the feet from falling off, file a groove in the bolt (and also file the bottoms so they're smooth). With tin snips or scissors, cut a number of small cuts partly down the metal cylinder of felt feet, and then you can fold the metal into the groove you filed into the carriage bolt end.
closeup of a foot (sspp5_small)

view inside base (ssp1_small) On the inside of the base I added pockets for unused index cards and cards with observations on them. You can also see the bubble level glued to the bottom, and one of the adjustable legs. Down the center runs a line which points at true North. The compass however points to magnetic North, which is 12° off to the right where I live, as you can see in the picture. Look here to find this magnetic deviation for your location.

Last update 18 Feb 2000

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