[PSUBS-MAILIST] Non developable surfaces

[Joe Perkel]

Thanks Alan, that's the kind of idea recipe I wanted.

Enjoy the rest of your trip.

Joe

Sent from my 
iPhone

On Feb 16, 2014, at 3:00 PM, Alan <alanlindsayjames at yahoo.com> wrote:

> Hi Joe,
> that sounds a lot easier.
> I cooked some cast acrylic that was just over an inch thick & was surprised
> how tough it was to bend. A bit like the bendiness of an eraser. When a local
> firm blew a dome for me, they had to get another clamping ring made because
> the original one looked like it would break under pressure. This mightn't be the
> case with acrylics other than cast. I don't know. What I'm getting to is that you will need to
> clamp it in place some how. I don't know how you intend to mount it, but if you 
> are bolting it on this is how I would do it...... I would put glad wrap over the area
> of the ballast tank where the acrylic was going, & coat it with an inch of plaster
> of paris, then when dry build it up with more plaster of paris so you have a strong
> p.o.p. shape the same as the ballast tank contour. Maybe cut the p.o.p. to size
> or mark around the p.o.p. with a felt pen on the ballast tank for positioning.
> Heat & drape the acrylic over the area & position the p.o.p. over it, with a sheet of
> felt between. Weight the p.o.p. with a sand bag to disperse weight & add more weight 
> on top of that.
> If that doesn't quite do it, after that process you could drill holes through the acrylic
> & ballast tank & reheat the acrylic & clamp it with bolts & a retaining ring.
> Not quite in Tahiti yet. Most people did there big OE in there 20s. I 've had to wait
> till my 50s.
> Alan
> 
> 
> 
> Sent from my iPad
> 
>> On 16/02/2014, at 6:00 am, Joe Perkel <josephperkel at yahoo.com> wrote:
>> 
>> Hi Alan,
>> 
>> I figured you to be distracted by Polynesian dancers by now! :)
>> 
>> Small window ala Nekton, but located in a spot where the shape curves in two directions. A flat slab like the Nektons would detract from the lines unless made too small to be practical.
>> 
>> The whole thought process here, is to expound on James Frankland's forward MBT by fully enclosing for the purpose of reducing tow drag.
>> 
>> Joe
>> 
>> 
>> 
>>> On Feb 15, 2014, at 10:39 PM, Alan <alanlindsayjames at yahoo.com> wrote:
>>> 
>>> Hi Joe,
>>> I'm not quite following you, but here are some suggestions.
>>> you can cut out an oval section from a sheet of ply wood or similar & use it as 
>>> the template to blow the acrylic. Or blow it in to a female form. However
>>> contouring it to the sub shape & having it bubble out from there seems difficult.
>>> The only way I could imagine you doing it would be to tip your sub on it's side,
>>> heat the acrylic sheet & drape it over the sub. Then trim it to shape & weld brackets 
>>> to the sub to clamp it & a female mold on. Then heat the acrylic & quickly bolt it & 
>>> the mold to the submarine. You could blow compressed air in to it through a through hull.
>>> Experimenting with a scale model would help.
>>> Hope that makes sense. Of course Greg is our resident expert.
>>> Alan
>>> Sent from my iPad
>>> 
>>>> On 15/02/2014, at 6:18 pm, Joe Perkel <josephperkel at yahoo.com> wrote:ex
>>>> 
>>>> 
>>>> How much trouble is it to form acrylic in two directions? As in following a complex hull form to make an integral window.
>>>> 
>>>> In other words a transparent section of MBT with a bidirectional curve.
>>>> 
>>>> Joe
>>>> 
>>>> 
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