DIY n120 Port Extensions for Nauticam Housings

I have been working on water-tight, pressure-proof 3D prints for a while now. I've been using some Port Floats for well over a year now that are still in perfect shape without a failure up to 100ft/30m across over one hundred dives.

I recently bought an old Olympus Zen glass dome port that should provide some perfect glass for a Curved 60mm Macro Port. I want to make a port body to receive the glass for that project. I figured a good stepping-stone along that path would be to first make a Port Body Extension Ring. Afterall, it is just a port that opens on both ends. :)

I made a rough draft design last week and iterated 5 or 6 prints tweaking the design and precise dimensions to get a perfect fit. I experimented with different materials as well, trying PETG, ABS, and finally ASA. The PETG prints came out fairly good, but I find that my printers just do a better, cleaner job with ABS or ASA. Smoother, cleaner, less stringing. ABS and ASA are also lighter weight and stronger in most ways than PETG along with better temperature resistance in hot environments. The final ASA protype print that I made was the cleanest off the print plate of all the iterations. I am using the same printing parameters that worked for watertight port floats, but these are much thicker and stronger.

Testing:

I have only tested the 3D printed port extensions by pulling a vacuum in the housing. No leaks after 24 hours. The next step is to test under pressure. Lacking any sort of pressure testing apparatus, I will probably just dive it to 30 meters in my old D850 housing with no camera installed.

Any suggestions on how or where to "Safely" pressure test a housing locally in Seattle would be welcome.

Ideally, I would want this to work to at least 50 or 60 meters so provide a safety margin. For reference, Nauticam advertises 100-150 meters. The port bodies are 12-14mm thick. My port floats have not failed at 30meters and they are only 2mm thick. CoPilot AI seems to think it should be good to about 17bar or 173 meters.

I decided to make 20mm and 40mm extensions to start with. My CAD design is parametric, so I can just plug in any value from about 15mm on up to create the model. I have not tweaked the design for n100 size ports, but that should be straightforward if I pursue that option.

I have several lens combos that need extension:

• 20mm:

  • 60mm macro port + 20mm for the Nikon 105Z lens

  • 140mm dome port + 20mm for the Nikon 8-15mm fisheye lens

• 40mm:

  • 140mm dome port + 20mm + 20mm extension for the Nikon 8-15mm + 1.4 teleconverter

• 70mm:

  • 8.5" dome port + 70mm for the Nikon 16-35mm lens

I use the 105mm and 8-15mm fisheye all the time. I bought a second 20mm extension so I can shoot both conveniently. However, I need to swap them around all the time if I want to shoot both the 105 and 8-15+TC in the same time frame. A 40mm port body dedicated to the 1.4TC setup would be a terrific addition to my collection.

A quick note on pricing of various options:

Saving money is NOT the goal here, it is much more about the satisfaction of building something myself. And building something that is unique and otherwise not for sale anywhere, like a custom Curved Macro Port. But it is interesting just to show what is possible.

• Printing with ASA costs about $2 USD in filament and 20-30 minutes of post processing labor, sanding, etc.

• Nauticam sells a 20mm extension for $390, 40mm for $430 USD.

• A rough quote from PCBWay is $165+shipping for an anodized aluminum CNC manufactured 40mm part based on my design.

• Sunk cost: Bambu P1S 3D printer sells for $399. One roll of ABS filament is $20 and enough to make ~10 port bodies.

• Labor cost for a retired engineer pursuing a passion project: $0/hour

Here are few images of the port bodies:

20mm and 40mm: PETG, ABS, ASA.

A Nauticam 20mm is over 200g. My ABS 20mm is 95g, the 40mm is 150g.

40mm ASA with Nauticam 70mm

40mm port body with 170mm dome port - Vacuum testing with Nauticam housing

This is very exciting. Thinking about custom stuff like N100 down to N85 without adding extension to allow using ASP-C Sony lenses on FF for when I want a more compact setup.

Or Nikonos adapters for cameras other than Sony.

Basically the weird stuff few people want.

Just now, Grantmac said:

Basically the weird stuff few people want.

My area of expertise!

I enjoy some out of the box thinking!

I just bought a large 10 bar pressure pot from a guy in Bellingham, then delivered it to a friend in Victoria.

Would have fit almost anything.

What about designing sealed end caps to allow pressure testing of parts off the camera?

Edited 15 hours ago15 hr by Grantmac

11 minutes ago, Grantmac said:

I just bought a large 10 bar pressure pot from a guy in Bellingham, then delivered it to a friend in Victoria.

Would have fit almost anything.

What about designing sealed end caps to allow pressure testing of parts off the camera?

That is certainly possible, at least one end cap. Plug the other end with an actual Port. Only issue is that now you are testing two parts and might not know which one fails.

Is the pressure pot big enough for a housing?

Pressure testing an end cap is very different than the extension ring; the forces will cause different stresses and deflections between the two. The pressure on the end cap will deflect the sides out and if you get a leak, you will not know if the seal was broken due to the cap's deflection. Also, the ring can withstand much higher forces since they will be compressive and bending forces are not involed. But if the test doesn't fail, you will know the ring design is good.

When I ran a pressure test on a housing in the past, I tied it to a line and dropped it off my kayak in the ocean. After a while, I pulled it up, saw no leaks, and called it good. I tested it deeper than what I was willing to dive to.

Ben

Tomorrow i am going a local Seattle dive site, Cove2, which has a pier over pretty deep water. I will drop it down and see what happens. If it passes, i can dive it to 100 ft or so on a proper dive, sans camera.

1 hour ago, Dave_Hicks said:

That is certainly possible, at least one end cap. Plug the other end with an actual Port. Only issue is that now you are testing two parts and might not know which one fails.

Is the pressure pot big enough for a housing?

The pressure pot could likely do a dome port but not a housing and port.

It's also 80# and now in Victoria.

The "cap" would be best designed as a hemisphere, not a flat shape.

I'm going to drop a housing off a long deep pier tomorrow and assess. Then dive it if all looks good.

A friend once built a pressure pot by cutting in half an aluminium scuba cylinder that had failed test and making a perspex lid for the bottom half, then tapping in a pressure feed. It was only for a few bar, so a cylinder that had failed a 200 bar + test pressure was not a bad risk. It was part of an undergraduate engineering project.

The trick on safe use is to completely fill with water, then only use a little air to pressurise - just like they do when cylinder testing, but only to a few bar.

Unfortunately it wouldn't be big enough for a real camera housing, but could probably have worked for a compact. He used it to test and calibrate old analogue depth gauges against a lab quality guage.