It would work except for one thing- glued
joints are only suitable if the forces acting on them are only compressive
forces. The orientation of the joints in your laminated dome would cause them
to be subject to tensile and shear forces. This is why ABS will approve a
radial glue joint in a sphere but not laminated viewports.
Greg Cottrell
Project Manager
http://www.precisionplastics.com
P please consider the environment before printing
this email
From: owner-
Sent: Tuesday, September 21, 2010
5:25 PM
To:
Subject: [PSUBS-MAILIST] acylic
dome
Greg,
Prompted by Jon's dilemma re viewports & wanting to get
down to 1000 ft, I'm
forwarding this idea for your scrutiny.
I've had thoughts about making a dome by stacking 2
rings of 100mm (4") thick
acrylic on top of each other & a disk on top
of that, & gluing together.
The first ring starts off as a 600mm (24") circle
cut out of a block of 100mm thick cast acrylic.
Then a 500mm circle (disk) is cut out of that. This disk is
kept to go on top.
Another disk is cut & ring formed slightly
smaller than 600mm diameter with a wall slightly larger than
50mm wide.
So you end up with 2 donuts stacked on top of each other
& a disc on top of this.
You either glue them together & machine them to a dome
or machine them close, glue them & sand & polish.
This would use about 1.2 meters x 600mm of 100mm thick cast
acrylic, & give you a dome 40-50mm thick.
Possibly a dome that would get you a 1000ft operating depth
for under $4000-.
If you used a larger diameter for the bottom ring you could
machine a flange on it too
The person who blew my dome told me the joins would be
invisible unless at eye level looking straight at the join.
Any thoughts on this idea thanks.
Alan