I was able to pick up a couple of lenses from projector tv's (at the dump) a few months ago and finally got the time to build a frame and mount it.
I got together with a buddy and we designed and built the first one in about 2 hours. And that included going to get the 2x2s, quarter round, two each of 4 inch carriage bolts/washers/nuts and one small U-shaped joist hanger. We built the second one in about 25 minutes.
I built the legs 53 inches high with mounting holes drilled at 50, 40 and 30 inches so you can use the unit for cooking from standing up height to knee high.
I mounted the small U-shaped joist hanger to the bottom lower left of the moveable section in order to align the unit with the sun. By lining up the opposing holes in the hanger, you can be sure to have the lense lined up with the sun thus making a sharper focus point.
It has been so overcast and/or raining that I couldn't test it until this afternoon.
The bad:
On a reasonably overcast day, you can't get the temperature above abient. The unit serves no useful purpose.
The good:
On a sunny day like today, a wooden paint stick will go from outside temperature to bursting into flames in only 11 seconds! It smoked for a few seconds and then burst into flames!
Total cost, using used lense and new building materials, was $23 each.
I got together with a buddy and we designed and built the first one in about 2 hours. And that included going to get the 2x2s, quarter round, two each of 4 inch carriage bolts/washers/nuts and one small U-shaped joist hanger. We built the second one in about 25 minutes.
I built the legs 53 inches high with mounting holes drilled at 50, 40 and 30 inches so you can use the unit for cooking from standing up height to knee high.
I mounted the small U-shaped joist hanger to the bottom lower left of the moveable section in order to align the unit with the sun. By lining up the opposing holes in the hanger, you can be sure to have the lense lined up with the sun thus making a sharper focus point.
It has been so overcast and/or raining that I couldn't test it until this afternoon.
The bad:
On a reasonably overcast day, you can't get the temperature above abient. The unit serves no useful purpose.
The good:
On a sunny day like today, a wooden paint stick will go from outside temperature to bursting into flames in only 11 seconds! It smoked for a few seconds and then burst into flames!
Total cost, using used lense and new building materials, was $23 each.
Comment