Nauticam vacuum pressure?

[tobyone 44]

Does anyone know how much negative pressure is produced by the Nauticam vacuum system?

At what pressure does the light go from red to flashing green and then to solid green?

[Interceptor121 843]

the light does not go into flashing green

it goes from blue to amber when you start pumping and then to solid green 

I do not recall seeing any official statement about the pressure differential which in any case will not be strong in the order of 100-200 mbar

Note that if you keep pumping it does not get more green but if you had a flood this pressure delta will make the water go in quicker

 

[tobyone 44]

Mine goes from red to flashing green to a solid green. It is on a NA-XT3 housing. It starts out blue when I turn the switch on,

[Interceptor121 843]

Mine goes from red to flashing green to a solid green. It is on a NA-XT3 housing. It starts out blue when I turn the switch on,

Maybe we see the flashing differently but the point is flashing only means air is being sucked out once solid it has reached at least the required differential pressure
You should not use the camera if the light is not solid as the system is not armed
The moisture sensor though acts independently


Sent from my iPhone using Tapatalk

[ChrisRoss 150]

I've seen posts in the past stating 200 mbar  vacuum.  There were people posting that they tried to get absolute minimum vacuum as they saw some advantage, but this seemed to lead to problems with the light going back to flashing green or yellow.  I routinely do two more pumps from when I first see solid green and that has been totally reliable.  

I suspect the issue might be that there are two states for electronics, first being a state where it watches for a reduction in pressure of sufficient magnitude which then goes solid green then slightly more vacuum turns on monitoring mode.   The electronics don't go back to green/yellow flashing if they alarm for loss of vacuum they go to flashing red, however people were reporting the system going back to flashing green/yellow which signals you don't have enough vacuum yet.

[tobyone 44]

The mail reason for the question was I was testing 3d printed parts for water tightness with a Nauticam housing and wanted to know the pressure  of the light changes. I just finished testing a 4 inch dome in a 3d printed Nauticam mount for the Lensbaby 180 circular fisheye.Will have test shots coming shortly 

I have used housings with both an axial and radial o-ring and never had a flooding problem. I think the single axial o-ring is more susceptible  to flooding if not pre vacuumed. Most failures will occur when minimally pressurized. I have had a Nauticam housing leak at surface that sealed while at depth. 

[TmxDiver 47]

18 hours ago, tobyone said:

Mine goes from red to flashing green to a solid green. It is on a NA-XT3 housing. It starts out blue when I turn the switch on,

I could be wrong, but if it goes from blue to flashing red (before you apply a vacuum), it means that the battery is running low. Is it a solid red before the vacuum or a blinking red?

NB: this has nothing to do with your original question, I just thought I would point out that your battery might need replacing.

- brett

[blibecap 29]

I believe that you will find the setting for switching from red to green is about 5" mercury vacuum. that would be the equivalent of about 6 foot deep. 

[tobyone 44]

Thanks for the feedback.

[ChrisRoss 150]

I think the risk is mostly the strength of your 3D printed parts, you can calculate the force applied to your part from the cross sectional area (port diameter and the external pressure).  The test at vacuum only tests that the o-ring is seating.  

[JohnLiddiard 31]

1) I have no expertise in 3d printing, so (2) could be completely wrong.

2) I have heard that some 3D printing processes can be slightly porous due to microscopic gaps between the blobs of printed material.

[Interceptor121 843]

If you want to pressure test your rig you need to take it to a dry diving chamber
A vacuum detection system doesn’t prove anything with regards to ability to withstand pressure as that is linked to the collapse/damage of materials not the failure of a seal


Sent from my iPhone using Tapatalk

[ChrisRoss 150]

A quick calculation shows that a depth of 20m the force exerted over the entire dome pushing inwards is 345 lb or 157 kg for an N100 port, so you part needs to be strong enough to withstand that without distorting.

[tobyone 44]

On 6/9/2023 at 12:42 PM, JohnLiddiard said:

1) I have no expertise in 3d printing, so (2) could be completely wrong.

2) I have heard that some 3D printing processes can be slightly porous due to microscopic gaps between the blobs of printed material.

 

6 hours ago, Interceptor121 said:

If you want to pressure test your rig you need to take it to a dry diving chamber
A vacuum detection system doesn’t prove anything with regards to ability to withstand pressure as that is linked to the collapse/damage of materials not the failure of a seal


Sent from my iPhone using Tapatalk

As far as the 3d printing process is concerned, yes you are correct that small spaces can exist even at 100% fill. But with a good slicing(g-code management) recipe you can over extruder to fill these voids.  On previous attempts to make port adapters, I would have to coat with epoxy and put under about 5 atmospheres of pressure . The epoxy was "sucked" into the voids, rendering a water tight component.I am using a PETG material which is very strong.

 

The ports have pasted the 24 hour vacuum test and now ready for the real world test. For pressure testing I prefer to test in water. You put "Crystal Light" a powdered drink mix on the interior of housing. Any leaks can be traced to the origin with the drip lines. Will test at about 5 atmospheres, without camera of course. I am confident the material has the strength to withstand the pressure. Printed at 100+ % fill it is extremely strong. The dome itself is about 4.5mm thick.