If the acrylic annealed for OpenROV?


#1

If the acrylic annealed for OpenROV?

The term annealing generally describes the heating of a material over a longer period. With such a method, it is possible for example to control the distribution of mechanical stresses in a component made of glass or acrylic.

I have not found any information about it.

Thanks for the reply.


#2

Hi Holger:

It depends on what the material is supposed to be used for.

In the case of the E_Tube, If it has been initially designed as a pressure pipe, it has been slowly cooled, to ambient temperature at the factory, giving time for the structure to get self balanced.

If it has been made only as a decorative mean, that cooling may have not been performed.

Optically granted acrylic matherial has also suffer a heat treatment in order to avoid structural irregularities.

Anyway, when calculations are performed for pressure vessels, the worst case assumptions are always made, and a sequrity factor is applied, that mainly depends on the role that the part is going to have in the design.

Those factors can be found at any of the ships or underwater vehicles building rules published by the different classification societies (Lloyd's, ABS, DNV ....... ) which are based on experience and laboratory tests.

Regards


#3

Hi Ion,

thank you for your reply.

I've read that acrylic when treated with heat, when bonding is not as fast from cracking and for our OpenROV that's important.
For this reason, I ask for it.

Greetings from Germany


#4

You're wellcome Holger.

And you're right. The heat treatment avoids stress concentrations, but if safety factors are duly applied, the part will not fail under the design conditions.

A high quality part, where internal structure has been fully homogenized (as fully as possible, perfection is only a theoretical concept), results a lot more expensive. But, as there are no weak areas, dimensions and material quantity can be optimized, and hence weights are reduced.

Have a look at this document that can be free downloaded.

ABS (American Bureau of Shipping)

RULES FOR BUILDING AND CLASSING
UNDERWATER VEHICLES, SYSTEMS AND HYPERBARIC FACILITIES
2012

Section 6 / 17.1

Here at Europe, we are more fond of Det Norske Veritas or the Lloyd's Register. Anyway, calculation methods are the same, and the ABS document is easier to be found and downloaded.

Regards and greetings from Spain :-)


#5

Hello Ion,
Thank you for your additional information.
I want to go wrong when gluing the OpenROV nothing.
Have bought the acrylic cement ACRIFIX 1S-0117 by the company EVONIK.

http://www.acrifix.com/product/acrifix/de/produkte/loesungsmittelkl...

Many greetings to sunny Spain


#6

Hahaha. I appreciate you greetings but ....

That's funny to hear how wrong people is about Spain weather. The concept you have comes from our South coast publicity for tourists.

Spain is the most Motainous country in Europe before Switzerland and the second regarding mean height over sea level, after Switzerland again (Most of our territory is around 1000m). Hence, appart from our south coasts, the weather is Mountain weather in most of the country, really cold and snowy during winter and quite hot (UV radiation) during summer, with cold nights all along the year.

Just now, we are around -10ºC at nights and around +1ºC at daylight, with quite a hard NW wind blowing from the Atlantic.

Sorry for this meteorology lecture, but .... my homeland is so different from that Touristic idea, that we are a little bit fed up.

Anyway, its true, our southeast coasts virtually have no winter becouse a mountains range running N-S isolates those lowlands from North and west winds,.... Foehn effect, you know? Thats the place mostly known abroad :-)

About cementing the endcaps ......

Be careful providing a homogeneus cement layer between parts.

The surfaces must be fully in contact with no bubbles.

The thinner the cement layer, the better.

Regards Holger. Dont hersitate asking anythig you need.


#7

Shame on me :-)
which is absolutely true. In the head you get the picture: Pure Spain = sun and since the sweetest oranges come from :o)

We are sorry for the wrong picture. Clear Spain and other regions which are most certainly very gentle at the right time of year.

Greetings at -1 degrees Celsius :o))


#8

OpenRovers HI, I now live in Spain, Madrid Really Want for my child’s school create the world class exploration program using Openrov. We bought one but we still not try yet. Could you help find the people (maybe there are English-speaking) in Spain WHO’s Understand OpenRov or have already installed and functional, maybe you know a good dive sites. Big thanks Vytautas . my phone 611272516


#9

Hi Kuriult:
I live very close to Madrid. Please PM me if you are still around here.

Regards