Hi Alan,
The T/Di ratio is 27 / 540
= 0,05
Page 486 of the handbook
acrylics says that the short time failure depth is 20 MPa =
2000 Meter .
For designing I used a
table of the GL which gives a operational depth of
400 Meter .
I am currently building a
new sub. (type) Name will be “NordicSub” as the owner of the
Eurosub wants to keep that name . ( I am okay with that as the word Euro sounds
not so positive here and now…)
This project used the
last domes so for more I have to do a new production run. I am now busy with
moving to Norway
(great coast for psubbing there!) so a new run will be after that.
The turbine bike is a project
from already 15 years ago. Great that they still write about it at the other
side of the world!!
Emile
www.nordicsub.nl
Van: owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] Namens Alan James
Verzonden: zaterdag 16 juni 2012
21:36
Aan:
personal_submersibles@psubs.org
Onderwerp: Re: [PSUBS-MAILIST] how
to fit the acrylic dome
what sort of
crush depth do you think you would have with the 27mm apex?
I noticed you
weren't selling domes on your site. What are you doing
with all the
domes you have been pressing?
I see you've
been gaining the attention of the media with your turbine powered motorbike.
From: Emile
<emile@airesearch.nl>
To:
personal_submersibles@psubs.org
Sent: Sunday, 17 June 2012 12:10
AM
Subject: RE: [PSUBS-MAILIST] how
to fit the acrylic dome
The
recess was needed to fit the dome in the ring. Is not exactly round after thermoforming
so machining is needed anyway.
The
bigger the base the better but the thickness on the apex is only
27 mm . We should calculate
with the thinnest spot.
I
also used a radius mill to reduce stress.
It looks like
you have a 28mm base to the dome & have eliminated 8mm with the 4mm angled
cut away
for the O
ring & the additional recess for the retaining ring around the
perimeter.
I thought the
base contained most of the stress & you would want to retain as much of it
as possible?
Are you still
pressing domes?
From: Emile
<emile@airesearch.nl>
To:
personal_submersibles@psubs.org
Sent: Saturday, 16 June 2012 9:07
AM
Subject: RE: [PSUBS-MAILIST] how
to fit the acrylic dome
But it is also
not done to machine a o-ring groove in the dome. Nemo’s first dome
cracked when the water o-ring froze!
Attached my
solution. Green is o-ring
Van:
owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] Namens André Eriksen
Verzonden: vrijdag 15 juni 2012
22:16
Aan:
personal_submersibles@psubs.org
Onderwerp: Re: [PSUBS-MAILIST] how
to fit the acrylic dome
From what you
said I made this sketch (attached). Is this a good way to fasten the dome?
It is not done
to drill / tap any holes in a acrylic dome. Stressraiser!
For shallow
divers you can glue .
Under high
pressures the dome contracts more than the ring
I use a o-ring
on the edge and stainless steel bands hold down the dome.
Flange also
possible for shallow divers. In the handbook of acrylics are some examples.
I`m new to
this forum, and are planning to build a 3 person sub.
I can`t seem
to find any plans or pictures on how to fit the acrylic dome for the
hatch. Is it screwed down on flanges with an o-ring underneath, or liquid
gasket/glue? I`ve seen some domes without flanges, how do they attach them?