We will start by putting the main internal structure together. The internal structure acts as a central mounting frame for the motors, wiring harness, and electronics tube.

You will need the pieces shown, which can be found in the two bags of acrylic parts (1 piece from 3mm bag and 5 pieces from 6mm bag).

You will have some acrylic pieces that have some debris from the laser cutting process. With the hex wrench, you can pop out the debris.

Remove the paper backing from the acrylic parts.

A knife or your fingernails can be used to start removing the paper from a corner.

Using acrylic cement correctly is essential to the OpenROV build.

The cement is solvent based, meaning it is not sticky but as it cures it bonds like materials.

Before you start, watch this great video on how to use acrylic cement from TAP Plastics.

The best way to apply cement is to hold the syringe bottle upright (tip at the top) and squeeze out a bunch of air, so when you turn the syringe bottle upside-down (and don't squeeze the bottle), air will burble inward and not allow cement to flow out. When you're ready to apply cement, lightly squeeze the bottle to overcome the vacuum pressure.

Only a little cement is required to make a good bond. Use the capillary effect to apply cement to a joint and have the cement work its own way into the space.

You will now cement together the ROV handle and vertical motor mount.

First, push the pieces together as shown.

Make sure they are together all the way and straight.

Apply cement to the joint between the two parts on both sides.

Keep them straight as shown in the second picture as the cement dries very quickly.

Next cement the two support pieces to the vertical support structure.

Attach the ROV handle to the 3mm piece as shown in image 1. Do not cement it in place yet.

Attach the vertical motor structure.

Cement all the connection points.

Next, cement the vertical motor support in place.

Now we are going to attach the base of the motors to the frame.

For this step you need your hex wrench (found in the fastener bag), 3 motors, and 9 each of hex screws, nuts, and washers.

Remove the motors from the box.

Loosen the two set screws on the motor base with the hex wrench.

Remove the motor from the base and set aside the motor. You won't need it for the rest of this guide.

The motor chassis has six screw holes so you can mount the motors properly no matter which side is placed forward in the acrylic cementing process.

Note the orientation of the motor mounts with the notched edge pointing downward for the port and starboard motor mounts.

When positioned correctly only three of the screw holes will be used.

Mount the vertical motor in the same way as the horizontal ones.

Note which side of the acrylic it is mounted to.

Continue your build by progressing to Guide 2.