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Thanks Greg & Jon,
My only apprehension about machining off the dome
flange & attaching a ring is that
I'll lose 1.25" of view from the bottom of my dome.
I've gone small with the dome (550mm O/D)
so this loss will be more exaggerated than
if it were bigger. The dome I've had blown was from
35mm sheet. I'm 10 mm thicker at the base than the
dome on the K250 plans someone sent me.
I'm thinking my choices are; restrict my depth
& go wit the heel reinforcement, or restrict my
vision & go with the glue on
flange.
Fortunately I have a 10mm thick dome the same size,
so this weekend I'll sit in my polystyrene mock
up submarine with my
dome over my head, try a few things & contemplate.
Alan
----- Original Message -----
Sent: Friday, May 28, 2010 2:53 PM
Subject: Re: [PSUBS-MAILIST] Flanged dome
support ring
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I always recommend that the flange be cut off. Even though Stachiw
shows supporting the inner heel, you have to remember that these were
early experiments. First they pressure tested a dome with a formed
flange (and of course it broke at the heel) So they reinforced the heel
and the dome went deeper. Even so, a further improvement was made when
Kittredge chose to cut the flange off and glue on a ring to use as
a hold down. This design eliminated the highest stress area (the heel)
and added years of service life to the dome- something that Stachiw
could not test. Modern subs with domes (like the deep worker 2000) use
straps instead of flanges.
So the moral is, even though Stachiw was the first and best work
done on acrylics, not everything you see there is the best solution
today. The few times I got to talk with Jerry on the phone he sometimes
discussed ideas he had come up with in more recent years that were not
in the book.
Regards,
Greg
--- On Thu, 5/27/10, Alan James
<alanjames@xtra.co.nz> wrote:
From:
Alan James <alanjames@xtra.co.nz>
Subject:
[PSUBS-MAILIST] Flanged dome support ring
To:
personal_submersibles@psubs.org
Date: Thursday, May 27, 2010, 5:29
PM
The've finally blown my dome after 1 year
& 2 weeks of waiting.
I'm leaving the flange on & need to
get a support ring made for the inner heel.
Is there an easy way of making the
support ring profile match the dome heel
profile, or do I have to find a grinding
wheel with a matching curve & manually
grind away. I presume it would be done in
a number of sectors.
It might be quicker if I do it
myself.
Any advice on this (Greg).
Regards
Alan
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