This laminating idea reminds me of the spherical windows that have been built from slightly curved hexagons. Those are not laminated of course, but they are still bonded. I remember seeing that the process for doing that was written up in Stachiw's book, so who knows, it might have something on laminating too. I guess we have to wait until the book ordering process comes through to find out! Brian, I'd recommend you give Greg Cottrell a call and pick his brain on this one. His phone is 301-412-8004. rgds, Alec -----Original Message----- From: Brian Cox [mailto:ojaibees@ojai.net] Sent: Thu 1/15/2004 11:36 AM To: personal_submersibles@psubs.org Cc: Subject: Re: [PSUBS-MAILIST] Acrylic laminating Emile, Wow! I'm happy that this idea may have some merit ! I know it is possible to get 3" thick plexiglass, PMMA (poly methyl methacrylate), and I think you can even get 4". I just picked up a small piece of 2" that I'm going to try milling. I priced a piece of 2" with a dimension of 24" square for $389.00. Also I was worried about the optial qualities of looking through the plexiglass on its horiziotal plane but it is not a factor, only if you bend the material is there a distortion of view. Another note, apparently there is a method of seeing stress cracks using polarized plastic film. Good Hunting! Brian Cox ----- Original Message ----- From: Emile <mailto:2stroke@hetnet.nl> To: personal_submersibles@psubs.org Sent: Thursday, January 15, 2004 5:49 AM Subject: Re: [PSUBS-MAILIST] Acrylic laminating Brian, I was thinking on about the same. Personally I think it will work. If sawed in donuts first , the inner part can be recycled. As a cnc machining specialist I can advice the flollowing production sequence: -saw donuts -turn the inner radius of each slice on a cnc lathe *precise* -bond the slices together matching the inner radius *precise* -Clamp the dome internal and machine the outside -sand and polish When I visited a large sea aquarium, I saw they bonded the 300 mm thick(!) acrylic but it was very little visable. maybe on a smaller scale it is even less visable. The local technical plastics company can supply up to 100 mm acrylic so that means less slices. The stress comes in the form of tension and a little bit shear . There is a great bonding area (what wall thiknes do you think about??) I dont think this will prove a problem on psubbing depth. What does a factory made 9"dome cost anyway ?? regards, Emile van Essen ----- Original Message ----- From: Brian Cox <mailto:ojaibees@ojai.net> To: Personal_Submersibles@psubs.org Sent: Monday, January 12, 2004 6:09 PM Subject: [PSUBS-MAILIST] Acrylic laminating Hi, I have an idea that perhaps has not been considered before with respect to acrylic domes / viewports. First off let me say that there is a good chance that this would generally be a bad idea but since I don't know that much about the structure of acrylic I will proceed. I've noticed with acrylic sheets that they can be laminated together with some type of bonding agent. I've seen this in large pieces of acrylic art work. They do this to add color in places and for other effects. I'm wondering if a dome was made using say 2" thick acrylic sheets laminated together so that you had say 5 sheets of 2" acrylic laminated together that would make it so you could have a 9" dome radius if you machined the interior. Or if the 2" sheets were cut into donuts first you would have a lot less machining to do to make the final dome. So the finished product would be an acrylic dome 2" thick made up of five layers of acrylic. The question is how thorough is the bonding between the layers of acrylic? And if a dome was made like this and then taken down to depth what would be the destruction characteristics that would occur? I doubt that the handbook for acrylic for submersibles addresses this idea but there may be some hint of it if it addresses laminating acrylic. The chemical that is used to bond the sheets is like an acetone type, I believe, and the sheets are essentially bonded chemically in this way but I am not very knowledgeable on the details. If this was a viable method it could reduce the cost of producing a dome. I'm ready to be shot down! Brian Cox _____ Deze e-mail is door E-mail Virus Scan van Het Net gecontroleerd op virussen. Zie voor meer informatie: http://www.hetnet.nl/evs/
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