Use spray adhesive and 3M clear packing tape to attach mylar to front and back of 4×8 insulation board. 3/4″ and 1″ PVC parts list as follows. LEDs are used as sensors beside the target window or solar cells to tell it where to aim the Sun. Details and changes at instructables under the name of zawy. A single axis design will be added to make morning reset easier.
Parts:
Lowes:
$21 PVC parts (see below)
$22 two 4×8 insulation boards
$5 Locktite general purpose spray adhesive
$5 PVC glue
$5 epoxy
$2 two 1/4″ bolts, 1.5 inches long, and 6 nuts
$2 three foot 1/4″ screw rod Lowes has
$5 clear packing tape, the wide plastic stuff like 3M.
$5 stainless steel wire cable
Ebay with free shipping or someone like mpja, bgmicro, futurlec, or allelctronics.
$4 12 V AC supply, 100 mA
$2 four IRF530 mosfets and four 10 Mohm resistors
$1 20 5 mm LEDs (needed to drive turn on the cheap mosfets)
$20 two 12 VDC motors, 100 mA, 20 to 200 RPM, preferably 100 RPM
$4 for 4 mylar emergency blankets. Previously I used $20 two mil aluminized mylar.
Free small gauge electrical wire from somewhere.
PVC list:
$4 two 10′ 3/4″ pipe high PSI (480)
$3 one 10′ 1″ pipe high PSI (450)
$3 pack 10 plus two 3/4 elbows
$1 two 3/4 T
$2 five 3/4 couple
$6 pack 10 1″ T
$1 two 1″ couplings
$1 two 1″ elbows
2″ of 1.25″ low pressure (thin wall) PVC pipe from somewhere
PVC cuts:
3/4″: 47″x2, 48″x2, 1.25″x2, 3″x2 (axis)
1″: 18″x2, 6.5″x2, 4.5″, 1.75″x3
Special cut: make lengthwise cut on 2″ length of 1.25″ low pressure (thin wall) pipe or use some other hack to join the two 1″ T’s between the 2 axis.
Building the AXIS: 3/4″ couplings rotate perfectly inside 1″ T’s. Connect two 3/4″ couplings with 3″ of 3/4″ pipe to go inside a 1″ T, so the 3/4″ stuff rotates inside. Now 1″ T’s, elbows, and couplings can glue to the outside of the 3/4″ couplings, VERY close to each side of the 1″ T so that they are NOT glued to it. So 1″ stuff is connected through the 3/4″ axis to other 1″ stuff at 90 degrees via a rotating 1″ T. To make the 3/4″ axis stronger against bending, coat the middle 2″ of the 3/4″ pipe with epoxy and embed fiberglass (of course you don’t have fiberglass netting on hand, so use four 2.5″ lengths of bare 12ish AWG copper wire, and bend each end into a 1/4″ L for more surface area connection with the epoxy, or find a 3/4″ metal pipe instead of the PVC).
Connecting Motor Shaft to Long Screw: The only hard thing that always seems to be a problem (with DIY’s like me who don’t weld…yet) is joining the 1/4″ screw shaft onto the end of the motor shaft. My solution was to use 1″ of 1/4″ copper tubing to go losely arond the outside of the motor shaft, dremel off a divot on the opposite side of the shaft from the flat side, drill 1/16″ hole through both sides of copper tube (off-center), and screw a screw through the copper holes with the shaft inside making sure the screw can go snugly across the divot so pushing and pulling the copper tube does not make come off the shaft. Then remove screw and tube, fill with epoxy, put back in place and screw again, and use pliers to squeeze copper onto flat side of shaft. The opposite side of the copper tube where the long screw goes in just uses epoxy. The motor shaft problem is that it is so smooth and epoxy only is not likely to hold and the stainless steel is not solderable with the copper.
Pivoting Motors: See the animated GIF images. I found a small screw I liked and found a drill bit to match the diameter. Then I made two very close hacksaw cuts into the 1″ elbow as shown.
Post time: Jan-10-2017