[TheForge] How to melt steel with sunlight:

[peter fels & phoebe palmer]

Imagining a swooping, mirrored,  smithy roof, mounted on  3 hydraulic 
columns
with a forge near the south wall.

On 11/27/2010 8:14 PM, Bruce Freeman wrote:
> A) We don't need no stinkin' cooking pot!
> B) That installation can get a cooking pot up to 6300*F = 6790*R =
> about 2 or 3 times any temperature a blacksmith or welder would need.
>
> The more I think about it, the more I think that a single 11" square
> Fresnel lens would do the trick.  Combine that with Peter's idea of
> flexible mirrors, and you can probably assemble an array of 1.5 meters
> square (that's about 5' square) at small expense.  I.e, mirrors direct
> sunlight onto Fresnel lens; lens directs light to focus.  Simple.
>
> Mount the assembly on a pivot to rotate the assembly to face the sun
> without the focus moving at all.  Once the device were set according
> to latitude, the tracking could be controlled by either a timer or by
> a very simple device that moves the assembly as the image of the sun
> through a small hole moves relative to a light sensor.  Make that a
> UV-sensor, and the tracking would work on cloudy days, albeit the lens
> would not produce nearly as much heat then as on sunny days.
>
> One warning -- wear a welder's helmet, as the focused sunlight
> contains quite enough UV to destroy your vision if reflected into your
> eyes.
>
>
>
> On Sat, Nov 27, 2010 at 10:47 PM, James Binnion<jbin at well.com>  wrote:
>> You might want to look at this. It will give you an idea what size installation you would be looking at for a hot zone the size of a "cooking pot" http://en.wikipedia.org/wiki/Solar_furnace
>>
>>
>>
>> On Nov 27, 2010, at 5:24 PM, peter fels&  phoebe palmer wrote:
>>
>>> Sounds even better.
>>> But we are talking about a pretty big fresnel lens then ...though i
>>> suppose a bunch of them could be used in a grid, given a bulge to mount
>>> them on.
>>> Those cheap dimestore mirror strips designed to fit on a wardrobe door,
>>> have the interesting property of bending into a mild arc,i
>>> found....which could be used as a focusing mechanism.
>>> Tempered glass will bend even further.
>>>
>>>
>>> On 11/27/2010 6:01 AM, Andrew Vida wrote:
>>>> peter fels&    phoebe palmer wrote:
>>>>> Thanks Bruce;
>>>>> That's delightful!
>>>>> Brings me back to my old proposed solar forge
>>>>> If one were to use an array of cheap mirrors with tracker/step motor
>>>>> rigs like Kurt's,
>>>>> combined with a big lens...say a pool of water in a plastic sheet hung
>>>>> from a frame.....
>>>>       Too much fuss.  Fresnel lenses can be made arbitrarily large yet remain
>>>> very light in weight.
>>>> ______________________________________________________________
>>>> TheForge mailing list
>>>> Home: http://mailman.qth.net/mailman/listinfo/theforge
>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>> Post: mailto:TheForge at mailman.qth.net
>>>>
>>>> TheForge mail list group photo site is
>>>> http://www.photoworks.com
>>>> Login: blacksmithblacksmith at hotmail.com
>>>> Password: anvil
>>>>
>>>> This list hosted by: http://www.qsl.net
>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>
>>> ______________________________________________________________
>>> TheForge mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/theforge
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:TheForge at mailman.qth.net
>>>
>>> TheForge mail list group photo site is
>>> http://www.photoworks.com
>>> Login: blacksmithblacksmith at hotmail.com
>>> Password: anvil
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>> James Binnion
>> jbin at well.com
>>
>>
>>
>> ______________________________________________________________
>> TheForge mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/theforge
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:TheForge at mailman.qth.net
>>
>> TheForge mail list group photo site is
>> http://www.photoworks.com
>> Login: blacksmithblacksmith at hotmail.com
>> Password: anvil
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>
>