How do add an air lock to my uw housing? I do not like latches

[blibecap 29]

Hey Dave

Yea I know of that product, I have tried to chase down the person who owned the company ( John Fiorda of Pacific Camera, in Costa Mesa, California, USA ) but just cant reach him. He is alive and well in California but no phone, no email and he doesn't return calls I have left at his senior citizens center. I was interested in the gage he was using but I am long pass that now. I think it is a great idea but it has to be simple to use and no to expensive. The unit I am working on will also incorporate a moisture sensor. I like the rechargeable pump that was noted in a previous post. We are on our way here so stay tuned.

[fotoscubo714 0]

Apparently, Reynolds had a similar unit, called the "Handi Vac" but is now discontinued http://www.reynoldspkg.com/reynoldskitchen...vac/en/home.asp. EBay has listings starting at $3.00 for the vacuum unit.

 

I was able to get my hands on one and found out that this unit ran on 6 replaceable AA alkaline batteries (see attached pic.). I have tested this unit and it also pulled 19 in Hg vacuum just like the Freshsaver. - Bo

 

 

While doing my last minute Christmas shopping at our local Target I ran into this Freshsaver Handheld Vacuum System.

 

It is fairly compact, rechargable, only $20 and draws 19 in Hg vacuum (48 cm Hg). See attached pics.

 

Instructions do not state how long to recharge (recommend 24 hrs on initial first charge) or how long a charge will last, and I have not had time to test it on a full charge.

 

When I have more free time I will see if this is workable with my vacuum connectors (see my prior posts here) on an old housing.

 

Have a great Christmas!

 

Bo

Edited December 28, 2009 by fotoscubo714

[okuma 64]

John survived a heart attack several years ago and closed.

[blibecap 29]

Hi Everyone

 

Well it's been a while since I have posted a update. I have been busy skiing and shoveling snow but I did find some time to work on the project. I have assembled the prototype and needed to make some changes to the original schematic. After the modifications it works great. I now have to run those modifications past the EE who is working with me on the project and then we will go on to the next step of making it small and using surface mount chips.

 

This section is a area inviting comments and feedback. Without getting too much into the details of how things work I will attempt to describe the circuit as well as it's functions. One of the concerns when designing the project was power consumption as well as space required as we already have the connection to the housing solved. We have a power saving feature installed that will really extend the length of the battery life. My minimum requirements were to be able to run on one battery for 12 hours a day for at least 7 days on a single coin cell. After all coin cells are not that expensive.

 

The circuit also contains a moisture sensor. With a good battery, anytime there is water in the housing you will get a red flashing alarm regardless if you are in power-saving mode or not. The unit will automatically come out of power-saver mode as we didn't want any manual switches etc.

 

If you have less than 2" of vacuum in the housing then you will be in power saving mode.

 

If you have from 2" to 8" of vacuum in the housing then you will see a rapid flashing red alarm.

 

If you have from 8" to 10" of vacuum in the housing then you will see a slow flashing red alarm.

 

If you have from 10" to 12" of vacuum in the housing then you will see a solid green safe light.

 

The way I figure it if you have a lose of vacuum you have a problem !!!!!

 

I am open to ideas and suggestions in this area.

 

More updates to follow.

 

Bill Libecap

[blibecap 29]

Here is a quick update on the project. We have the circuit design complete and working. I have purchased the surface mount components as well as the PCB for 25 initial units. We have assembled, tested and calibrated three units for testing purposes are currently in the testing process with two units for testing and a spare. After 1 week of diving we haven't seen any problems or had any failures in either of the two test units. It is a very reassuring feeling to look down at the housing or in the eyepiece and see the little green (I'm OK) led flashing.

 

Some updates on the unit. The size is 1" X 1.5" and about 3/8 inch thick including the battery. If you don't have that much room there ia a option for a remote battery that would cut the thickness in 1/2. We have the current units installed in a Ikelite housing for a Nikon D90 and a Sea&Sea housing for a Nikon D300.

 

We are still working out the installation procedures as well as the options and cost but re still on target for a complete setup to be in the range of $500 or less. All of the external fittings are stainless steel and the battery is a very readily available 2032 coin cell. The board has the options for two red (danger low vacuum) led's as well as two green (I'm OK, safe vacuum & dry) led's. The board also incorporates a moisture sensor that overrides the vacuum led's.

 

I don't see any reason that this system couldn't be incorporated in a video housing as well as a still camera housing. As stated earlier in this thread the design is proprietary and the PCB assembly is made of surface mount components so that will only be sold as a assembly. The blocking plug for the vacuum fitting is custom made but all the other parts (vacuum fitting, vacuum pump and inlet connector) are available over the counter. We hope to be able to start delivery of parts kits as well as preform turn key installs in August.

 

If you are interested or have questions please feel free to ask and I will try my best to get back to you.

[Paul Kay 65]

Fascinating, however..... in my experience the vast, vast majority of significant leaks are due to main or port 'O' ring failures and usually this is down to the user simply not being careful enough in assembly.

 

Placing a camera in a low pressure environment may result in dust being sucked into the camera and lens leading to dust in both the sensor box and internal air spaces within the lens when its allowed to re-pressure, one is a pain to deal with, the other can be expensive. I understand the logic of doing this but it might cause some potential problems that should be considered. It might be worth fitting a filter over the pressure valve to reduce the possibility of dust entering the housing but the housing may need to be kept scrupulously dust free too. Just a thought (from someone who has had dusty lenses!).

[blibecap 29]

Hey Paul

I agree that "vast majority of significant leaks are due to main or port 'O' ring failures and usually this is down to the user simply not being careful enough in assembly." That is why this product been designed, to safely detect these problems before entering the water. Is there way to test this?

 

We are not "Placing a camera in a low pressure environment" but we are placing the camera in a absence of pressure so instead of bowing dust in it may suck dust out. Since we are sucking air out and not blowing air in there is no need for a filter.

 

Vacuum is sometimes a little hard to understand. In this situation we reduce the pressure inside the housing in relations to the pressure on the outside of the housing. This is the same thing that happens every time you take your housing to 10-15 feet deep in the water.

[fotoscubo714 0]

Here is a quick update on the project. ....................

 

If you are interested or have questions please feel free to ask and I will try my best to get back to you.

 

Hey Bill,

 

How can we DIY this thing? or is this the wrong forum?

[Paul Kay 65]

We are not "Placing a camera in a low pressure environment" but we are placing the camera in a absence of pressure so instead of bowing dust in it may suck dust out. Since we are sucking air out and not blowing air in there is no need for a filter.

When you re-pressurize the system air has to enter the camera and lens, and along with it is the potential for particulates to enter too. This will increase the potential for dust to be sucked into the sensor box. Many older lenses do suffer from internal dust which has a (slight) effect as it can decrease contrast but it also will reduce the resale value of the lens. In point of fact you are only increasing the pressure differential between the inside of the housing and the outside by 1 bar so effectively as the housing enters the water it has a clamping pressure already applied equivalent to 10m depth. I have no problem with this at all, but it does have associated 'side-effects' which users should be aware of - dust is especially irritating with digital sensors so anything which exacerbates it needs to be carefully considered - hence why I suggest a filter for stopping dust ingress upon re-pressurization.

[blibecap 29]

Hey Bill,

 

How can we DIY this thing? or is this the wrong forum?

 

 

Well I had planed for it to be a DYI thing. I will have the electronics module and the special not over the counter parts available as well as a list of the over the counter parts and some ideas on the install. Not quite a total DYI. Correct me if I am wrong but I dough that there are a lot of people here that want to build there own circuit board and install surface mount components and calibrate the sensor that has to be in a vacuum to calibrate ETC. The custom fitting plug requires machining stainless steel and this will be easily done on a lathe or a mill. It is DYI as you assemble the auxiliary parts and install it in your housing.

 

The total parts list looks like this:

...The vacuum sensor / moisture detector board

...The custom fitting plug

Over the counter parts

...The vacuum pump preferable with a vacuum gage

...The self sealing vacuum fitting

...The indicator led's

...What ever wire, fittings and attachments required to mount the circuit board, led's and vacuum fitting.

 

Is that enough to call it DYI?

 

I will also be offering a complete installed turn key package on my web site.

Edited July 20, 2010 by blibecap

[blibecap 29]

When you re-pressurize the system air has to enter the camera and lens, and along with it is the potential for particulates to enter too. This will increase the potential for dust to be sucked into the sensor box. Many older lenses do suffer from internal dust which has a (slight) effect as it can decrease contrast but it also will reduce the resale value of the lens. In point of fact you are only increasing the pressure differential between the inside of the housing and the outside by 1 bar so effectively as the housing enters the water it has a clamping pressure already applied equivalent to 10m depth. I have no problem with this at all, but it does have associated 'side-effects' which users should be aware of - dust is especially irritating with digital sensors so anything which exacerbates it needs to be carefully considered - hence why I suggest a filter for stopping dust ingress upon re-pressurization.

 

Paul

We will be looking into the cost of adding a filter.

Thanks

[blibecap 29]

Paul

We will be looking into the cost of adding a filter.

Thanks

Hey Paul

Well we did some research and was able to find a 10 micron filter for less than $10, however after a short discussion we are concerned that this will not solve the problem. When you pull a vacuum on the housing it is true that you suck a small amount of air from inside the camera as well as inside the lens. When you release this vacuum and allow the housing to equalize so you can open it you allow air to enter the housing from the surrounding atmosphere. At first it seems like installing a micron filter in this line would solve the problem however, after closer study one realizes that the air that is going back into the camera and lens is the air that is already inside the housing so adding a filter would keep the inside of the housing cleaner however I don't think that will address your concerns. I think we all have concerns for dust and don't work in a dusty environment.

 

So if you are really concerned that this device will add to the dust your camera or lens collect then I guess that you can skip the install and skip the dust and HOPE that it is sealed well and that your camera and lens don't collect water. I personally don't think that the dust issue is enough of a concern to shy away from a tried, trusted method of assuring that the housing is sealed air tight.

[blibecap 29]

End of test period update

 

After two weeks of testing in two different camera housings, we haven't had any sensor errors or problems. The sensor did catch one possible leakage problem during the test period that turned out to be a very small piece of lint on a o-ring.

 

In the Sea&Sea housing we would open the housing at the end of the day and allow it to be open over night, allowing the sensor to go into power-saving mode until the next morning at which time we would pull a vacuum before going to the dive site. That battery continued to work for over three weeks as it was not continually working. On this housing there is only one set of led's installed in that setup as that is a user option. The led’s are viewable from the top of the housing.

 

 

On my setup in a Ikelite housing our battery life was 10 days or about 240 hours of continuous usage. Each evening I would open the housing, install a fresh memory chip in the camera and a fresh camera battery and make any port and lens changes needed for the next day. I would then immediately pull a new vacuum on the housing and let it set blinking green until the next morning. I in my installation I have two red (warning) led's as well as two green (everything OK) led's installed. I have one pair of led's visible from the top of the housing and another pair visible in the viewfinder.

 

Again the battery we are using is a 2032 coin cell that cost less that $4.00.

 

I also would add that we are very pleased with the performance of the sensor and it was really a comforting feeling getting the housing out of the bags at the dive site and seeing the green led just blinking, knowing that the housing was sealed air tight.

[Guest echeng]

Got photos of the setup? I like the idea of having a sensor and lights that tell you the housing is happy.

[Paul Kay 65]

At first it seems like installing a micron filter in this line would solve the problem however, after closer study one realizes that the air that is going back into the camera and lens is the air that is already inside the housing so adding a filter would keep the inside of the housing cleaner however I don't think that will address your concerns. I think we all have concerns for dust and don't work in a dusty environment.

 

So if you are really concerned that this device will add to the dust your camera or lens collect then I guess that you can skip the install and skip the dust and HOPE that it is sealed well and that your camera and lens don't collect water. I personally don't think that the dust issue is enough of a concern to shy away from a tried, trusted method of assuring that the housing is sealed air tight.

Yes, I suspect that you are right - the actual problem will be dust already inside the housing which may get sucked into the camera upon re-pressurisation. In order to minimise this all I can suggest is that the re-pressurising valve should have a smallish hole to ensure that a substantial jet of air doesn't stir up any dust already inside the housing - you have probably already considered this though.

[John Bantin 101]

Got photos of the setup? I like the idea of having a sensor and lights that tell you the housing is happy.

 

http://www.divernet.com/Diving_Gear/diver_..._hugycheck.html

 

The latest version puts the LEDs over the viewfinder eyepiece.

 

http://www.divernet.com/Diving_Gear/diver_...gyfot_d700.html

Edited July 25, 2010 by John Bantin

[blibecap 29]

Got photos of the setup? I like the idea of having a sensor and lights that tell you the housing is happy.

 

I am working on pictures and details and hope to have them posted this week. We will be working on the first production run this weekend.

[Fred.littleford 0]

I have been following this thread and I was hopefull that there would be a follow up post soon but I haven't seen any update for about two months. Does anyone know what the status of this project is?

 

Fred

[adamhanlon 0]

Hi Fred,

 

Have a look here.

 

Hope that helps!

 

Adam