[Member-Forum] Moment of Inertia

[Douglas Suhr]

"Hi Paul,
can you tell us a bit more about the thermo forming of the 165mm sphere"

I too am interested in hearing more about how such a thick personnel sphere
is manufactured. Sounds like a daunting and frustrating task (with the
multiple failures mentioned). ~ Douglas S.


On Wed, Mar 26, 2014 at 9:17 AM, Dan Still <stillphototheater at yahoo.com>wrote:

> Anything with chips in them hate humans.
>
>
>   On Wednesday, March 26, 2014 7:29 AM, Joe Perkel <josephperkel at yahoo.com>
> wrote:
>  Wow, 24+ hours for email delivery and doubled to boot.
>
> Can iPads go insane?
>
> Joe
>
> Sent from Yahoo Mail for iPad <http://overview.mail.yahoo.com/?.src=iOS>
>
>  ------------------------------
> * From: * Joe Perkel <josephperkel at yahoo.com>;
> * To: * member-forum at psubs.org <member-forum at psubs.org>;
> * Subject: * Re: [Member-Forum] Moment of Inertia
> * Sent: * Tue, Mar 25, 2014 4:00:01 PM
>
> Hi Paul,
>
> The question is anecdotal based on an off the cuff thought of upsizing the
> shell O.D. to 42" from 36". I am very hesitant to do this do to weight and
> handling issues however, several members have made a compelling rationale
> r/t simple comfort. At 53 I'm 6' 190 lbs and should expect that L to W
> ratio to change by build time!
>
> I have to think a bit about the shell thickness r/t welding and corrosion
> issues, but Depth no more than 350'. I seem to remember a cross section
> drawing of a T section somewhere with a simple L/W/H relationship to shell
> T, but can't find it again.
>
> I'll take that pdf if you don't mind. I'm not at home and won't be until
> later this week to do some number crunching.
>
> Thanks Paul!
>
>
> Joe
>
> Sent from Yahoo Mail for iPad
>
> Sent from Yahoo Mail for iPad <http://overview.mail.yahoo.com/?.src=iOS>
>
>  ------------------------------
> * From: * Paul Moorhouse <paul at steel-fish.com>;
> * To: * 'PSUBS Member Discussion Group' <member-forum at psubs.org>;
> * Subject: * Re: [Member-Forum] Moment of Inertia
> * Sent: * Tue, Mar 25, 2014 9:10:06 AM
>
> Joe
> As it happens, this is my day job. I have been designing submarine
> pressure vessels for the last 28 years. I am sure there are others on the
> forum who do this but I am happy to help if you would like, and others at
> PSUBS should the need arise.
> Frame size and spacing is inter-related and there is no one answer. I have
> developed some models based on the European pressure vessel code PD5500 so
> running a new configuration is easy and surprisingly quick. PD5500 produces
> much lighter vessels than ASME VIII which is really aimed at chemical
> plant. In this way it is more similar to military codes but it does rely on
> quality assurance levels that do not generally come with home construction.
> So to cater for this, you put a factor in. I apologise in advance for all
> of the calculations being in metric but give me info in either.
> I would need to know
> ·        Outside diameter
> ·        Shell thickness
> ·        Shell material
> ·        Frame material
> ·        Diving depth
> ·        Length of parallel body
> ·        Ends, hemi or 2:1 dished.
> ·        Preferred frame spacing
> ·        Inside or outside frames
> I can send you the PDF of the work sheet as the PD5500 sums do look very
> pretty.
> The next step is to design the hatch penetration and I can help you here
> also.
>
> This guy can thermo form your acrylic
> http://www.airesearch.nl/
>
>
> Regards
> Paul
>
> Paul Moorhouse
> www.steel-fish.com
>
>
>
> *From:* Member-Forum [mailto:member-forum-bounces at psubs.org] *On Behalf
> Of *Joe Perkel
> *Sent:* 25 March 2014 03:55
> *To:* PSUBS Member Discussion Group
> *Subject:* [Member-Forum] Moment of Inertia
>
> Where did I see the rule of thumb for T-section rib sizing relative to
> shell thickness? I can't seem to find it now.
>
> Joe
>
> Sent from Yahoo Mail for iPad <http://overview.mail.yahoo.com/?.src=iOS>
>
>
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