Hello from Illinois (soon back to Arkansas)

[Oddmar]

I've been lurking/reading/learning from this forum for the past couple years, but although i thought i had joined apparently i hadn't. So i did that. Probably just confused as i have been posting over at rcgroups for awhile.

I've been wanting to explore various clear lakes and quarries since i was in my 20's, but only in the last 10 years have i developed the technical background to build what i dream up.

For years i've been a welder/ fabricator, own my own shop, dabble in homemade RC FPV planes, quadcopters, and most recently a Traxxas Summit 1/6 scale. I have run a sign company for the last 30 years and still have all the equipment. I know (and have the tools for) carpentry, auto mechanics, plumbing, computers, video surveillance systems, etc. It seems the more i learn about one subject, i can cross-reference that knowledge into my other skills.

Used a trolling motor to motorize a canoe back in 98', but without the boat i sink better than swim. My good friend ran an underwater salvage operation in Okinawa back in the late 80's which is as close as i've gotten to scuba diving. Although we certainly discussed the hobby enough. Never having flown in a full-size private plane or helicopter didn't stop me from being thrilled as i fly FPV. If i can fly through the air, looking down at the scenery, while sitting safely at my ground station on terra firma, i should be able to dive and explore underwater at 300+ feet while sitting safely topside as well.

Every time i design an entry-level ROV i can't ignore my desire to have a good flexible arm on it to move/grab stuff. And looking at the prices of the ESC's and motors, building a small one isn't too far of a stretch from just building a big one. Like i discovered while doing sculpture...Why sculpt an eagle with a 4ft wingspan when i can make one with an 11ft wingspan for just a few dollars more?

I can dream it, I have the electronics and fabrication knowledge to build it, now all i have to do is afford it...lol.

Since i don't have anything in the water yet, and this section seems to have had recent activity, i'm going to post my parts list and design illustrations below. Keep in mind this is for a 60" long x 40" wide x 42" high small work-class rov. 6-dof with (2) 10-dof manipulators. 8 onboard cameras. (8) 400KV brushless thrusters. 235Ah FLA battery pack at 18VDC. Adjustable bouyancy. 8" dia, 48" long 3/8" wall aluminum pipe for the WTC. 8" dia 1/2" wall acrylic hemisphere for the main 78x zoom camera. Pan/tilt on the front, top, and rear cams. Live viewing of all 8 cameras at once. 32 sample/tool containers. 22k+ lumens of LED's.
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1. (10) 150A Brushless ESC's $65 ($650) Hobbyking
2. (10) Turnigy 4258 400kv Brushless Motors $40 ($400) Hobbyking
3. Fathom-X Tether Interface Board set (2) $160 Robotshop
4. (2) TP-Link 4-port Gigabit Ethernet Switches $15 ($30) Amazon
5. Pixhawk Flight Controller w/ Ardusub firmware $60 eBay
6. (2) Raspberry Pi3's $40 ($80) Robotshop
7. 32 channel ADC w/I2C (topside RaspberryPi input) $40 FERCSA on tindie.com
8. SSC-32 Servo controller (ROV servos/lights) $40 Robotshop
9. (4) 20 EC3 bullet connectors $6 ($24) eBay
10. 1000' CAT6 Stranded CM,550MHz,24AWG,100% Copper $123 Amazon
11. (3) SLIGC125 6V 235AH Golf-cart batteries 68lbs $144 ($432) Batteriesplus
12. 8-ch DVR $100 Amazon
13. (10) Eachine 1000tvl 110* microcams $15 ($150) Banggood
14. Panasonic SDR-T50 78x zoom Camcorder $50 eBay
15. (20) 624 lumen 12v T10 Led's $23 eBay
16. (2) 7" ID 1/2" wall acrylic hemispheres $140 ($280) plastic-domes-spheres.com (custom)
17. (4) 4" 3/8" wall acrylic hemispheres $40 ($160) bluerobotics.com
18. (1) 7" ID 3/8" wall Aluminum pipe 4' $330 onlinemetals.com
19. Bar100 1000m depth/pressure sensor (I2C) $250 BlueRobotics
20. Celsius Temp Sensor (I2C) $56
21. 1 gallon Mineral Oil $21 Amazon


$3,419.00
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Edited to shave off over $1,000.

[leeinmt]

Your design appears well thought out and doable. Good luck on scrounging for parts.

My ROV project is about half done, but progressing slowly because I keep thinking of better ways to do things, such as using magnetic coupling for gripper motors.

I have acquired various components from Blue Robotics have been very happy with their quality, fair pricing, and prompt service. Using their thrusters has saved me a lot of stress from trying to make my own. Same with the end caps, hull penetration hardware, and potting kit.

[Ian MacKenzie]

I'm looking to design a 7 function manipulator for my next ROV. I was thinking mini hydraulic rams. I'd like to see your ideas/sketches. Maybe collaborate. I'm going to 3D print whatever I design. it'll probably be about half the size of what you're going for.

[Oddmar]

For ROV's of this size I'm more of a fan of linear actuators over hydraulic rams. Easier to control an electric motor than the flow of hydraulic fluid. Cheap too, especially if you build your own linear actuators out of cordless drills and threaded rod. Inside a bicycle innertube flooded with mineral oil?

I don't have a 3D printer but I'd like the Creality CR10-S4, 40cm3 print area and $570.

Since i have a welder I'll probably build my manipulators out of aluminum. I'm not sure 3D-printed parts will stand the stress applied by linear actuators.

On the hydraulic side of things, I've seen some fine control systems out there, namely SteelWrist. They just showcase their products, but as a knowledgeable man (read: mad scientist) i can tell they're using servo-controlled proportional hydraulic valves. https://www.youtube.com/watch?v=MAkn_6Osmco&t=797s

I've seen some small-scale stuff done with high-end scale construction equipment. But it's commissioned by the company that builds the full-size equipment, then awarded to top-dollar clients, mainly. https://www.youtube.com/watch?v=2D2ocn4NAQg

As to building a small ROV, remember, the larger/heavier you make your ROV, the more stable it'll be. It's a combination of how far the buoyancy is from the ballast, and Newton's 1st law.

Sure, i'd love to collaborate. That's why we're members of this forum, right? I'd be glad to help.