X12 Frame

This page remains a work in progress.

	Frame Summary
Vehicle	X12, ROV Triton
Construction	Water-jet 6061 aluminum
Contributors	Tyler Stagge
Success?	Yes

Description

At the risk of sounding arrogant, this is probably the best and most well-thought out frame we've had in quite a while. It has proven to be excellent in service.

Taking inspiration from X5 and X7, this frame was a substantial departure from the vertical plate layout of X8 through X11. The horizontal layout of the main plates allows a much more efficient use of space.
Like those of X8-X11, the frame is built from water-jet 1/4" thick aluminum 6061 sheet, connected using both standoffs and built-in mortise-and-tenon joints.
X12 is less passively stable than previous vehicles, though that is not necessarily undesirable.
- The Power Box, a major source of buoyancy, is on top, though biased to the rear to balance the Logic Tube.
- Though the foam was not designed until later, the frame was designed with foam in mind (i.e. we knew what the max envelope would look like, made sure the geometry would flow nicely, and added holes.
The brand new use of customized thruster ducts (FIXME), which were designed in parallel with the frame, provided a great deal of freedom in their placement and eliminated the shoddy 3d-printed thruster mounts of X9-X11 (FIXME).
Since camera placement is absolutely critical to a usable and effective ROV, the secondary cameras were placed in CAD and their views checked against all tools and props (using virtual cameras in Solidworks) well before the frame was due to be manufactured. In fact, the "deep V" on the bottom rear of the frame was specifically to improve visibility of the rear-facing secondary camera.
- Checking all tools against props is also what prompted us to mount the AM higher than the PM.

Miscellaneous but notable features:

The handle cutouts were deliberate, and even included holes that were eventually used to mount printed handle 'wraps' integrated into the foam.
3D-printed "shoes" protect the aluminum feet from damage when inevitably scraped along the bottom of the pool. They also reduce friction and provide design flexibility. Plans for shoes with ball bearings, wheels, and shock-absorbers were toyed with to varying degrees.
- The angles of the feet were deliberately chosen such that the ROV can be rested stably at an angle (a la X10's octagonal frame and very unlike X11's bizarre near-circular side plates).

Holes were added to mount the panel jacks for quick-detach pneumatic fittings to make connecting/disconnecting the tether more convenient. They were also placed right next to the subconn and ethernet connectors from the tether (in contrast to X11, where the tether plugged in in three disparate locations).
- For once, we incorporated dedicated clipping points for strain-relief.

Extra holes were included, flanking the bolt pattern for the primary manipulator, in case additional tools were needed. These ended up being used by the Pin "Yeeter" (FIXME) and Bottom Scraper (FIXME).
Since the solenoid enclosure was something of an unknown, two bolt patterns were provided: one for the WIP X12 solenoid enclosure (FIXME), and one for the X11 solenoid enclosure (FIXME) just in case.

Development, Manufacturing, and Testing Notes

Like we did for X10 and X11, the work-in-progress frame design was mocked-up using laser-cut foam board and straws, all hot-glued together. This was very useful for getting a sense of scale, testing assembly, checking hand access, discussing potential improvements, and discovering flaws. As a direct result, we resolved to make the design "swoopier", and discovered that several cross-drilled holes would require a specialty right-angle drill to make.

We got quite the bang for our buck on our aluminum sheet stock:

Known defects/problems:

The tether has the potential to interfere with the operation of the AM (FIXME).
Tool access for mounting the solenoid enclosure is rather shite.
There was a slight manufacturing fuck-up. A feature in CAD that padded material around the holes for several of the structural stand-offs broke just before DXFs were exported. So as not to blow-out some thin walls, we had to make some custom #6-32 - to - #8-32 standoffs.