OpenROV #439 - insert name here


#1

Hello fellow OpenROV users

here i will post a build-log of sorts !

i had initially been looking at the excellent designs by Mr Russell Coffield and team at Interspec http://interspec.org/ but felt ‘out of my depth’ with the software side of things. Thats when i spotted a part-assembled OpenROV on a well known auction site, that came with loads of invaluable accessories gathered by the previous owner including T100 thrusters and machined aluminium endcaps.

So OpenROV #439 is a version 2.5B for which i intend to utilise the standard OpenROV electronics platform with the intention to carry out the following modifications, many of which are inspired by the interspec designs :-

  1. A custom built chassis from router cut HDPE or similar, with float pontoons from router cut polyurethane foam.
  2. Thrusters shall be Blue Robotics T100 , using the standard 18A ESC’s as supplied with OpenROV
  3. On board Li-Po battery packs. ( 2x 11.1V 3S Lipo, 4500mAh )
  4. A proprietary neutral buoyancy tether if i can obtain something suitable for reasonable cost.

So the last month or two has been spent in what little spare time i have, reading and trying to understand the OpenROV system ( software notwithstanding - i will leave that to the experts ) , planning my attack on the build, purchasing some components and taking steps backwards due to a blown ESC and resulting fried Beaglebone - which i am pleased to report is now completely resolved.

i now have electronics all working, and thrusters functioning from joypad control- seemingly correctly albeit in a bucket of water.

Next Stages are:-

Name the project.
Tidy up wiring in main electronics assembly - in particular shorten the camera USB lead.
Make seperate wiring junction box
Make battery housing(s)
Design & make chassis

i will post sporadic updates as and when i make any progress!

Regards
Stuart


UK OpenROVers / ROV enthusiasts - meetup?
#2

Here are the assembled main tube ( original OpenROV acrylic tube with machined aluminium endcaps - wiring harness shall be passed through 3/4" BSP Hose barb and potted in, with plastic hose & stainless jubilee clip exterior sheath )

Note i have shortened the camera USB lead simply by removing the jacket, and removing the plastic sheathing from the USB plug & resoldering the shortened cable . this has considerably reduced the clutter in the main tube and makes much less work for the camera servo. I also replaced the LED power supply wires with more flexible wire, again ,mainly to help the servo action .

The last picture shows my intended junction box which is a IP68 cast aluminium box made by “Retex”. the gasket seal doesnt look too clever but i will augment the seal with a line of silicone when assembling the box. I have various sizes of IP68 cable glands which will be threaded into tapped holes in the box and cables shall be potted inside. - the M12 gland with strain relief is the perfect size for the T100 thruster cables. Battery leads, IMU cable, and tether shall all be connected inside this junction box & filled with silicone or some similar re-enterable potting compound…
( the potted cable gland technique is taken from Interspec.org design , and other similar variations on homebuiltrovs.com )

The brass fittings are to be end cap vents to replace the syringe design on the standard OpenROV endcap.

…next need to build battery housing(s) for 2x 11.1V RC lipo packs, and some means of accessing the charging connectors.