/diy/ - Do It Yourself

>>451881
The best cookers are well-insulated, solar box ovens with a full panel reflector array. They are easily made from cardboard and foil with thermal glass.

>>451881
>Is there a way to make them detatchable and re-aimable ?

certainly, but that added complexity is not needed. focus them once and mount them permanently, then just aim the entire array at the sun.

If you live somewhere really hot you can get away with a really easy one. I live in Perth, Australia and in summer we go weeks on end with [about 100 degrees F] temperatures. My neighbour has one that he puts on his driveway for an hour or two before he wants to eat. It's only a box with the inside painted black and with a glass lid, not reflectors or anything, but it works/

>>452456
Ambient temperatures don't play much role in solar cookers. You can cook even on slightly overcast days with a good solar box oven.

I've used mine in the dead of winter when temps are as low as -5F and still cooked food in about 45-60 minutes, depending on the thermal mass of the food I'm cooking.

>>451881
Parabola solar cookers need to be adjusted very often, like once every 15 minutes at most. With a well designed solar box oven you can only need to adjust it once every hour or so, but once every 30 minutes would be optimal of course. The trade off is that a parabola solar cooker can give you near instant frying temperatures if it is designed correctly.

>how I can allign all the mirrors.

Build it indoors. Let if face a single light in a dark room. Use that light to help align the mirrors by aiming the reflection to the pot holder area.

>detatchable and re-aimable ?
>way to rotate the whole contraption ?

Yes, but as >>452400 states, aiming them once then just moving the dish is a far better solution. You can add a heliostatic device to track the sun if you want. I can be a mechanical timer based (egg timer + lazy Susan) or electronic based that actively tracks it, but will need an electric source of some kind. You should at least have some way of easily adjusting it on 2 axis because the focal point of these things is very small and goes off quite quickly. For my box cookers, I just prop them up and/or rotate them as needed on wheels.

>should I use to raise the thing I want to heat up ?

The pot holder needs to be metal. You can use a welded wire grid so that more sunlight strikes the bottom of your pot/pan directly.

>better alternatives than tiles of mirrors?

That is the best you'll get for a parabola solar cooker.

>any idea's ?

As stated in >>451897 you can make a fast cooking solar box cooker. My best ones reach 450F in a few minutes, but are for baking, not frying, unless I want to fry at 450F or less. I use my Fresnel lens for frying.

>>451881
the parabolic dish wont work unless its pointed directly at the sun. good luck.

>>452605
not op

Thanks for the idea's everybody.
I was aimlessly browsing on the internet when I found this img. I guess something like this would be awesome, just a couple things.

Is that styrofoam under the mirror ? Wont that melt ?

>>451897 says something about insulation, given that I only have 100*100*50 CM to work with, is it a good idea to create a wooden box of the above size, insulate it with Aluminium bubble foil, put mirrors in them and allign them to aim just below the center top of the box, and slide a huge piece of plexiglass over the whole contraption. Will only 50 CM of mirror-space be sufficient to cover a 100 by 100 CM base ?

>>452467
I am sorry for the confusion between frying and cooking. Point is, I do not really know what I am going to do. The primary point right now is trying to get the contents of a pot hot. From there on we get points for; originality, portability, setup time, possible down time, effectivity, whether it can boil water, and finally those who can actually prepare a meal with it get more points. Depending on the effectivity of the device that will be either soup or something more amazing like such as Lasagne, or boiled broccoi & potatoes & a hamburger

>>452701
you idiot, you forgot to embed this img

>>452711
why are the mirror on the out side corners indented?

>>452734
each individual mirror is flat. To approximate a parabola they need to be angled.

... Really man?

>>452701
>Is that styrofoam under the mirror ? Wont that melt ?

No. There's no concentration of sunlight there. In fact the mirror is reflecting the sunlight away from it. I wouldn't use foam for that anyway. It isn't very durable for such outdoor uses as that.

>insulation

For a solar box oven, only use cardboard, not wood, unless you need a box frame. Bubble foil uses plastic, you can just use cardboard for insulation too. Cardboard will shrink after the first couple uses so expect to add a couple extra layers in after that. Fiberglass insulation will work well too.

>plexiglass

Use real glass. Two layers is best with 1/8" air gap between them. The inside glass needs to be tempered glass so it won't shatter. Plexiglass will melt as will foiled bubble wrap if they are in contact with the cooking heat.

>50 CM of mirror-space

Use foil glued to cardboard or mirrored metal, but not glass mirrors for solar box cookers. Use 4 reflector panels, 1 on each side of the box.

>cooking

Check these out,

http://solarcooking.wikia.com/wiki/Solar_Cookers_World_Network_%28Home%29

http://solarcooking.wikia.com/wiki/Category:Solar_cooker_plans

Here's an old pic of one of mine. A prototype camping solar box cooker. The towel is an additional the insulator. The main insulator was 1 inch of cardboard. It also used 2 pieces of normal plate glass (higher temp cookers need tempered glass on the inside). Cooking time at that low a temp (250F/121C max) was about 2.5 hours.