Low cost STEM ROV kit design

Hi. I’m David, one of the Typewriter Repairmen who has excelled in the NURC challenges since 2009.
We have built several ROVs for this contest: NotBob in 2009, Babs in 2010, Biff in 2012, and Casper in 2019. Two of these ROVs are in the movie Spare Parts.
Casper is based on the BlueRobotics hull and thrusters. We built Casper in 2019, attempted to use it with the PixHawk control system, couldn’t drive with it, and ran Babs instead. After the pandemic eased, we went to the 2023 NURC contest in June and found that there was only one other team, a middle school team that was not quite able to get their ROV working in time for the contest. We had refitted Casper with a Teens clone of the Babs control system and were able to complete the mission handily.
We loaned Babs to the middle school team, and they did quite well also.
Fredi, the creator of NURC, then asked the Typewriter Repairmen if we’d be interested in producing a low-cost ROV kit that schools could buy at a subsidized price to allow them to compete without having to figure out how to build an ROV from scratch. This would greatly increase the appeal of the contest, and provide a higher level of competition.
All of our previous ROV designs were one-off, so they were hand crafted. Designing for mass production provides quite a different set of constraints, which end up requiring the skills of a full-bore product design team. Fortunately I’ve been designing interesting products for 20 years, so this is fun instead of hard.
We have spent the last 6 weeks designing this ROV kit. It is optimized for high performance, ultimate simplicity, low cost of manufacture, ease of assembly and servicing, and driving fun. The design is all made of 2D plastic parts, to get the cost to a tiny fraction of that of typical machined aluminum construction.
We are updating the Babs control system to use Teensy processors instead of PICs, because the Teensy is the best of the Arduino software ecosystem. No operating systems, no network cameras, no latency. Fingertip configuration of all drive and telemetry parameters from the operator’s gamepad.
Also, it’s going to be completely open source hardware and software, free for anyone to make.
2 fore-aft thrusters, two up-down, one side-side. 2 feet/sec drive and dive speed.
Gamepad control with full configuration at user level, no compiling required.
24V shore power (future will have onboard battery)
Cat6 tether cable for control/telemetry, speaker wire for power
Tilting video camera with LED illumination.
Front gripper claw.
Depth rating probably 50m for now, limited by tether.
The BOM currently is under $700 for the whole thing at prototype parts prices.
Sound interesting to anyone?

Hello David! This sounds like a fantastic project!

I was on the Jesuit High School (also known as Site 3 Engineering) robotics team back in the day and competed in the 2008 and 2009 NURC competitions. I definitley remember the name Typewriter Repairman (how can you forget such a great name) and we probably ran into each other at the event!

I spent about 5 years at OpenROV helping to design and produce open source kits (as well as Trident). The kit vehicle (IIRC retail price was $899) had some of the same goals (open-source, low-cost, learning tool, etc.). That said, the vehicle was designed around what existed at the time a decade ago and technology has come a long ways since then. It sounds like you have some great specs and I am so happy to see people innovating in the low-cost kit vehicle space! Congrats on getting as far as you have and I can’t wait to see the design you come up with!

Hi @Nixiebunny, welcome to the forum! :smiley:

It’s always exciting to have more options in the marine robotics space, and there’s a special place in my heart for those with an accessibility focus that’s suitable for hobbyists and those in the STEM education space. Thanks for sharing your story and your ideas so far, and I look forward to seeing where this goes from here :slight_smile:

To clarify, is there going to be a camera that just records onboard rather than providing a live stream preview to the operator? If so I would note that there may be difficulty operating at depths beyond the distance people can see into the water, especially if it’s unclear where the bottom is or whether there are things in the water that the tether could get caught on.

You don’t seem to have mentioned anything about electronics enclosures. This thread may provide some useful insights from others’ ideas if you’re planning to make custom ones :slight_smile:

Hi. Glad to be here. I don’t know if you are familiar with the Typewriter Repairmen team. We have been building ROVs for a long time. The kit that we are developing is a distillation of the best of our historical ideas, reworked for low cost and simplicity. You may be aware that it’s really hard to make something that’s obviously the right solution. We keep surprising ourselves with little tricks that take us closer to the ideal.
The camera provides a live video feed with low latency. The cable seals and electronics enclose seals are identical in function to the BlueRobotics ones, but made at much lower cost and complexity. We have our first prototype in the water already. It seems to run pretty well.

Cable seals are made of a counterbored hole, filled with a bit of automotive vacuum hose, compressed by a laser cut acrylic washer held down by an aluminum plate with two hold-down screws. Like a wetlink without the ten dollar price tag.