New Products: 3" Series and 4" Series Aluminum Tubes!

Originally published at: New Products: 3" Series and 4" Series Aluminum Tubes! - Blue Robotics

Hey there, friends! We are deeply excited to announce today’s new product: aluminum tubes for the 3" Series and 4" Series Watertight Enclosures. These aluminum tubes have significantly greater depth ratings, better heat transfer to the water, and a hard anodized black finish. Both tubes are bored out from the inside for optimal wall thickness and to reduce the enclosure weight. The 3" Series tube is rated for 500 meters (1640 ft) and the 4" Series is rated for 400 meters (1312 ft).

Both tubes are available now (in fairly limited quantity initially) separately and as options in the watertight enclosure configuration pages.

Please note that the 3" Series tube is 8.75" long, just like the battery tube on the BlueROV2. Both of these tubes are drop in replacements for the enclosure tubes on the BlueROV2. We'll get into more details on that once we've done more testing at depth!

2D drawing showed the bored out inside diameter to decrease weight and optimize depth rating.

As you may have seen on our social media, we have a new pressure test chamber, the #Crushinator!! The Crushinator will be able to reach pressures equivalent to 1000 meters underwater and will take our products to a whole new level of performance, reliability, and integrity. It can fit an entire BlueROV2 inside for testing!

Last week, we took a prototype aluminum 3" Series enclosure to about 750m before imploding. That's nearly 5 times the depth rating of the clear acrylic enclosure! Check out The Crushinator's first victim below. RIP.

Yesterday, we took a 4" Series tube down to 610m before it imploded. Even after crushing, it remained sealed and airtight! Check it out.

The enclosures are derated somewhat to allow for safety margin and variation between different tubes. These tests were all done with aluminum end-caps but we'll be testing out the acrylic and dome end caps in the future! Onwards and downwards!

If you have any thoughts, please join the related discussion on our forums here!

1 Like

That’s great news Rusty. What depth are the current thrusters and the foam block rated for on the Blue 2?

Thanks, Todd. The thrusters have been tested fairly deep but we haven’t officially rated them yet. We expect them to work just fine at 500m. The foam blocks on the BlueROV2 are rated to 244m (uncoated), but if coated they can handle 488m. I’m not sure how accurate those rating are - they are from the manufacturer.

If anyone starts diving the BlueROV2 past 100m with these new enclosures, I’ll be really interested to hear how you manage to do it. My limit is about 100m even with the new 400ft anchor rode I put on my boat. I’m about maxed out for position keeping unless someone has some sort of dynamic positioning.

Huh, neat. Are you planning a higher depth rated camera portal window too? Something that can match those for depth?

Also if someone were to send you a 3d printed side plate part to test in the crusher, would you have any interest in doing so?

Now you know the fun that I get to have crushing my creations :slight_smile:

Forgot to ask! Are you using a face or radial seal on your end cap?

@piercet - Yeah, the current dome can already go pretty deep but we’d like to have one that can handle the same as these enclosures.

We’d be happy to toss in a 3d printed part during one of our next tests if you’d like. I’m guessing it will absorb water very quickly. We’re considering offering testing as a service if companies/people are interested, but that’s far down the line.

@hscadden - Indeed! It’s been a long time coming! I remember discussing the initial thoughts for this years ago! We are using a face seal for the end cap and the flanges use a double radial seal. This is the exact same flange as our standard 4" Series enclosure.

Rusty some of the SL printed items would stand a MUCH better chance then PLA/ABS etc. for 3D printed because of how the layers are stressed or in the cause of SL printing … at least there are no layer boundaries … the material is all crosslinked.

Have you considered trying polycarbonate vice acrylic for the domes? Or another option might be glass epoxy casting. Some of the epoxies that I use are clear and strong as all heck. I have one that I tried to break the bond between it and a sandblasted interior of a connector and it took well over 1000 psi of force to do anything. Frankly it did a compression fracture in the epoxy and it still maintained the bond.

@hscadden - Polycarbonate does not laser weld as well as acrylic and we rely on that process. Additionally, polycarbonate only passes about 88% of light, which is really important at depth when you don’t have a lot of light. I think our best bet is making a thicker one.

I’ll send a pair of abs printed frame sections, one coated if you want to pm me an address to ship them to.

Tim,

We’re at:

Blue Robotics Inc.
4030 Spencer St, Ste 102
Torrance, CA 90503, USA

-Rusty

ok, great. I’ll send you a pair of the lower robot arm mount sideplate sections after I get them printed and prepped this weekend.

Will you guys be including these as an upgrade option for BlueROV2 kits? Do you know what the price difference will be?

1 Like