Zeroing in on the details (Trident Kickstarter Update #24)

Original post : August 4, 2017

Hello everyone!

Our last update was quite short as we wanted to focus on letting everyone know about the status of our injection molded shells. There are many other bits of news relating to our DVT build and other progress that I wanted to write about, so in this update, that’s what I’ll focus on.

Injection Molded Topside Shell

One thing we’ve made some great progress on is the WiFi Topside module. As described in a previous update, we had to do some fairly involved engineering work to manage the thermal budget for these parts. Materials selection was an important element of this, and we ultimately chose a fairly exotic plastic that is augmented with ceramic to increase thermal conductivity of the topside shell. The injection molded parts that use this plastic have arrived, and we’ve been happy to find that they work well enough to use in final production. Holding these topsides is a strange sensation. Because they transfer heat from your hand very quickly, it feels as if you’re holding metal rather than plastic. To show the difference using a thermally conductive plastic has on heat dissipation, I wanted to share these photos taken with our thermal imaging camera. We’re pretty happy with how well the WiFi Topside adapters have turned out, and we hope you’ll enjoy the strange feeling of holding them as much as we do.

OpenROV Trident
Comparison of thermal dissipation of WiFi Topside built with normal plastic (left) and special thermally conductive plastic (right)

DVT Assembly Line build-up

As we’ve been testing the new parts that are arriving, we’ve also been building up our DVT production line to make sure everything integrates nicely. Our contract manufacturing house, located here in the San Francisco Bay Area has been working closely with us to make sure we have consistent processes for assembling the vehicles. We’ve also brought in a few manufacturing experts from our network as an extra layer of support to ensure everything is being done optimally. Building large quantities of a product - particularly a mechanically complicated product - requires a lot of process control so that varying teams of workers can always get the same results. As we’ve continuously improved our procedures, we’ve been able to shift our role from actively participating in the assembly process to overseeing the manufacturing team as they build prototypes to our specification - giving feedback and advising on areas that can use improvement.

Tether Reel

We’ve also been able to do more prototype field testing to understand any potential rough spots in the overall user experience with Trident. To improve the experience, we created a simple reel for the 25m tether that fits in the carrying box with Trident and holds the WiFi Topside in place to keep things organized. Because coiling wire in a single direction induces twists, the reel has also been designed so that it is intuitively coiled and uncoiled from the same side so twists created from the coiling process are undone by the uncoiling process. The shape of the reel also allows the tether to be pulled off of it as it rests on the ground so a hand can be free to control the vehicle as it moves out into the water. The reel is simple, but it seems to do its job well. We’ll be including one of these reels in every Trident package.

OpenROV Trident
OpenROV Trident

Velcro Strap

We’re also adding a velcro strap to each Trident package. The strap is a simple thing to add, and we think it will be very helpful to have around because it can be used to route the tether along the tail of the vehicle in certain deployment scenarios such as ice diving, cave exploration, or shipwreck penetration. Normally, the tether should come directly out of the connector at the center of the vehicle so that Trident maintains turning authority even if there is tether tension. For operations in confined areas such as the ones described above, the operator may want to run the tether off the back of the vehicle so if it needs to be retrieved by pulling on the tether, it moves straight backward instead of creating a T-shape with the tether that can get fouled on surrounding obstacles. The velcro strap can also be used to secure the WiFi Topside during normal operation.

OpenROV Trident
For situations where there are many obstacles, the velcro strap can be used to route the tether along the tail of the vehicle

You’ll also notice that the tail of Trident now contains a series of lights that shine through the shell. These lights are part of the internal Tail Board electronics we’ve added, and can be used to show battery level and other status indicators for the vehicle.

OpenROV Trident
Velcro strap can also be used to secure the WiFi Topside during operation

Controlling device support

Another aspect of the user experience we’ve been thinking about a lot recently has been device support. We described in an earlier update that our initial release of Trident will only work with Android devices since developing a high quality iOS app in addition to Android would require a much larger team and more resources than what we have right now. Many of our supporters who have iOS devices have asked if there are specific tablets we’d recommend for Trident, so we’re vetting an array of options now and will post a list of them soon. In general, the main requirement is that the device runs Android 5.0 (Lollipop) or higher, and ideally has plenty of onboard memory or support for external memory in order to record video. We’ve also gotten requests to sell a custom controller that is optimized for using Trident and comes with the necessary software pre-installed and tested. We’re looking into this option now and have already found a manufacturer who could work with us to develop the ideal Trident controller. We’re compiling a list of emails for people who would be interested in buying this device if we were to come out with it at a later point. You can subscribe to that list by clicking here.

In the coming weeks we will continue to rapidly refine our production process, test the new (hopefully last) batch of injection molded shells, and verify that every aspect of the vehicle is working in a satisfactory way. We will continue to solidify our timeline as we learn which systems require additional process control through testing. We are working hard to reach a definitive shipping calendar. Stay tuned for more information about that. As always, you can reach us at [email protected] if you need anything in the meantime. We will be back in touch with more information soon!

Thanks as always,