Left Enclosure Assembly Instructions - LoCO-AUV/loco_config GitHub Wiki

This page contains a description of the assembly process for the internals of the left enclosure of LoCO. Note that there may be slight differences in your build compared to these pictures, depending on your fabrication of certain parts, and the progress of the LoCO project over time. When figuring out what size screw to use for everything, please consult Screw/Bolt Listing, although for many of these parts, you can make modifications if you wish.

CLICK ON THE PICTURES TO SEE A FULL-SIZE VERSION

You can check out this Assembly Video to watch this being done.

Mounting The Plug Holder

The first step is to mount the 3D printed plug holder to the MDF. Place nuts for penetrators in the appropriate places (consider epoxying them in for stability), and screw the part to the MDF. Test fit with an end cap before epoxying anything.

Mounting the Batteries

Now, you need to mount the batteries. Start by mounting the battery holders, with the appropriate nuts/bolts. Check the Screw/Bolt Listing to find the appropriate ones. Once you've mounted the 3D printed parts, put in two batteries, to check that they fit, then remove them while you complete the rest of the assembly.

Mounting the Power Distribution Board

Now, mount the PDB to the MDF base with the appropriate screws. You need to solder everything to your PDB before mounting, but you'll also need to layout your parts on the board to decide on cable lengths. Or, you could solder connectors (like XT60s) to the PDB, and then use terminated cables on each end. Please be careful not to overtighten, and make sure that all the required leads are soldered on first.

Mounting the Raspberry Pi and Pixhawk

Now, attach the Raspberry Pi to the MDF, with the appropriate screws. The Pixhawk goes on top, but it's just mounted by velcro. Make sure that the 3D printed part is mounted on the RPI first. At this point, it's also easiest if you make sure that the Pixhawk power supply and the RPI power supply cables get routed under the RPI to their final locations. It's possible to pull them through after the fact (or run them over), but it's cleanest and easiest to just put them under and the Pi now.

Mounting the Power Switch

Now, mount the power switch on the outer edge of the MDF. This one will be difficult, as it's very tightly fit in.

Mounting and Connecting the Camera

Depending on the camera you're using, this may differ, but in general, attach the camera to the mounting part, then attach the mounting part to the MDF. For the BlueRobotics Low-Light Cameras, there are three mounting holes.

Mounting the Rear End Cap

The end cap is attached to the 3D printed part with two penetrator nuts pressure fit/glued into the 3D printed part. So once you've got the 3D printed parts attached to the MDF and the penetrator nuts in the 3D printed part, you can attach the end cap to the end cap holder with two penetrators, using a penetrator wrench. This may be difficult, as the threads on penetrators sometimes are difficult to line up. Make sure you've already got all of the cables attached to the end cap before you do this step, attaching them afterward is frustrating at best.

Connecting Everything

Now, we've got to connect everything. This will come in several parts: the Raspberry Pi GPIO, the Pixhawk inputs, the Pixhawk outputs, the power switch, and the network harness.

Raspberry Pi GPIO

First, just the active fan power supply is attached...

Now the RPI's power supply.

Now the Pixhawk telemetry cable.

Pixhawk Input

First, make sure that the Pixhawk's power supply is attached.

Next, attach all the input cables: Telemetry to Telem1, power to power, and the depth sensor to I2c.

Pixhawk Output and ESCs

First, we plug the cables from the right-hand rear thruster into an ESC, and plug that ESC's signal cables into Pixhawk main out 1.

Now, plug the cables from the left-hand rear thruster into an ESC, and plug that ESC's signal cables into Pixhawk main out 2.

Lastly, plug Pixhawk main out 3 into two IECC cable pairs to connect the signal to the right enclosure, where the ESC for the central(pitch) thruster will be attached. We use orange and orange-white cables.

Power Switch

First, you need to connect the power switch to the left enclosure's PDB. For this, just match the cables: black, yellow, red (assuming that you fabricated both ends with the appropriate colors).

Now, connect the two shorter cables to an IECC (preferably the same one you used for the ESC bridge). We use brown and brown-white.

Network Harness

Lastly, get an IECC for your network harness, and connect it to the RPI network adaptor.

Conclusion

At this point, you've got a finished internal sub-assembly for the left enclosure. Move on to the right enclosure.