This instruction set, for OpenROV v2.6, is a work in progress. We have posted the photos taken so far to help people with kits get a general idea of how things go together. Please post questions about the build on the OpenROV Forums.

To build the ROV, you'll need the parts shown (which are all included in the v2.6 kit). If you're starting from scratch, you'll want to consult our Bill of Materials before getting started.

If you have an ROV with a serial number of 1200 or higher your kit also includes the battery adapters that are shown in the second picture. If your ROV has a serial number of 1400 or higher you have a battery adapter as well as there are a few different parts, shown in the third picture. Check out this blog post to learn more about the changes.

Tools you will need (not included in kit):

Glues/solvents/lubricants: Devcon "Flow Mix" 2-Ton Epoxy (two 14mL syringes should do it), Acrylic Cement and Hypo Applicator(BD-25), super glue, hot glue gun and sticks, silicone spray or jelly for lubricating o-rings and protecting motors

Electronics/wiring tools: Soldering iron, solder, helping hands, safety glasses (recommended), wire strippers, flush cutters, heat gun, electrical tape, and a digital mulitmeter

Hand tools: Sandpaper, small hacksaw or pipesaw, small set of screwdrivers, tape measure with metric markings, needlenose pliers, wrench, and painter's or masking tape

Educators: Use the Team Build Flowchart to manage multiple students working on a single OpenROV.

Batteries & charger are not included in the kit

OpenROV 2.6 is designed so that many different "c-cell" sized rechargeable batters can be used.

Please see the blog post HERE for information about batteries.

If you plan on using the Trustfire Li-Ion 26650 batteries, no further action is needed.

If you plan on using the Batteryspace Li-FePO4 batteries, which we recommend, you will need to build the adapter. The assembly instructions for this are HERE. Don't worry, we will remind you about this later in this guide after your battery tubes are assembled.

Batteries, chargers, and adapters can be found in our webstore.

To start out, put the internal structure together. You will need the pieces shown (which can be found in the large plastic bag in the kit). The internal structure acts as a central mounting frame for the motors, wiring harness, and electronics tube.

The pieces for the internal structure come with a paper backing on them which can be removed. Before doing so, however, it is good to test fit all the pieces to get a feel for how they all go together.

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

Your very first step will be to cement together the ROV handle and horizontal shroud support... Here we go!!

Remove the paper backing from both sides of the pieces and slide them together as shown.

Push the pieces together as shown.

Make sure they are together all the way and straight, as the cement dries very quickly.

Apply cement to the joint between the two parts

Now it is time to cement the mounts for the motors.

Remove the paper backing from both sides of all the pieces and assemble them together as shown. We will be cementing the three small pieces first.

Once the pieces are in place apply the cement to bond them together.

Next attach the largest piece and cement it to the three that you just put together.

Next, attach the handle/horizontal shroud support piece that you made in the previous step.

It should be a snug fit, so don't hesitate to push a bit to get it in place.

Cement the handle to the motor mounting as seen in the first image.

Next we will cement a little tab (the small rectangular piece with a hole in the center) to the top of the handle. Make sure to remove the paper before cementing it. This is for the propeller shrouds to rest against later.

You're almost done with the internal structure! After cementing the Main Tube Cradle pieces and Bulkhead Supports, you'll be done with the internal structure.

We will attach the Main Tube Cradle pieces. These are the L shaped ones that hold the electronics tube. Once they are in place cement them together. Be generous with the amount of cement used in the areas indicated to keep these parts from breaking off.

Finally, we will attach the last two pieces! These "doublers" help to hold this assembly in the frame. The second image shows the pieces (the ones shaped like the monsters from pac-man) being cemented on.

When attaching these pieces make sure that the tab is facing up as shown.

The Internal Structure is now assembled! Now is the time to inspect all the joints between each part and make sure every interface has been cemented. Apply additional cement to any gaps or missed joints.

Congratulations! You have completed the internal frame assembly!

We'll need to make a few modifications to the brushless motors so that they can work underwater. The main modification we'll make will be to attach new wire leads with waterproof insulation.

Start by removing the motor bell (the metal cylinder surrounding the motor) using small pliers or a screw driver to pry off the c-clip. Once removed, set the c-clips aside as you will need them later.

Once the C-clip is removed, the bell can be pulled straight off the motor. It may take a fair amount of force before the bell comes off.

Use a sharp razor to remove the outer shrink tubing from the motor lead bundle. Be sure not to damage the thin magnet wires coming from the motors, as this will damage the motor.

Now cut a slit in the inner shrink tubing on each of the wires. The slit only needs to go from the center of the tubing outward (you don't need to cut along the entire length of the tubing) This way, you won't damage the wires coming from the motor, and you'll be able to pull off the shrink tubing once you de-solder the original motor leads.

We're now at the step where we begin soldering.

If you are new to soldering, we recommend that you check out these links to help you get up to speed.

Video (concise, step-by-step)

How-To Guide (a very basic intro)

Heat the solder junctions with an iron to remove the leadwires. After the leadwires have been pulled off, the shrink tubing should be easy to pull off as well.

Next, cut a total of 17 pieces of one-meter long 20awg stranded wire. (Nine will be attached to the three motors, two will be attached to the spring terminals for the two battery packs, and six will be used as auxiliary wires for external devices.)

Strip a small amount of insulation off the ends of nine of the one-meter wires, tin them, and solder them to the motors.

After soldering each leadwire, inspect that the solder joint is smooth and shiny (not dull and rough, which would indicate a "cold solder joint" that won't conduct or hold well).

A cold solder joint is when the wires and solder are not heated to a high enough temperature resulting in a bad joint that has a higher tendency to fail.

Cut quantity 9 pieces of waterproof heat shrink tubing, length should be 2-3cm.

Apply a small amount of hot glue to the joint as shown. Make sure not to get any of the hot glue on the motor.

With the hot glue still warm, slide the heat shrink tubing over the joint.

Heat the tubing with a heat gun until the gel lining and hot glue inside oozes out from the tubing on both sides.

Cover the waterproof shrink tubing in each bundle with a 3 to 4cm- long piece of larger, regular shrink tubing.

Shrink the larger tubing over the bundle of wires for each motor as shown.

Repeat these steps until you have three completed motors.The motors are now ready!

We will now assemble the battery tubes.

Use a medium grit sand paper to roughen a corner of the spring terminal. The spring terminal has two holes- one with a lip and one without a lip. You'll want to roughen one of the corners near the hole without the lip (the hole with the lip is better for allowing the wire leading to the other terminal to pass through without chafing)

Melt a glob of solder onto the sanded area of the terminal.

Strip and tin one of the one-meter wires, pass the stripped part of the wire through the hole without the lip, fold the stripped part of the wire onto the glob of solder you've made on the terminal, then solder the two together.

Repeat these steps with an additional piece of wire on the second spring terminal.

Sand one side of the plastic disk with two holes (as shown). This will create a better surface for the spring terminal to bond to. Also roughen the bottom side of the spring terminal with sand paper.

You'll need two longer lengths of stranded 20awg wire for the forward button terminals in each battery pack. Cut two lengths of wire that are each 120cm long.

Thread the wire from the spring terminal through one of the holes on the sanded plastic disk, and the new 120cm-long wire through the other hole on the disk as well as the empty hole (the one with the lip) on the spring terminal as shown.

Apply super glue (cyanoacrylate) to the roughened surface of the plastic disk. It's not a bad idea to wear rubber gloves when working with super glue so that way you can avoid getting it on your hands.

Place the spring terminal down against the plastic disk. Make sure the holes on the spring terminal align with the holes on the disk.

Cement the outer (the largest one) and middle aft endcap disk (the C shaped one) together. Make sure that the rounded grove in the edge of the smaller piece is aligned with the hole on the larger piece, and the two disks are concentric.

Before cementing the inner disk with the spring terminal to the two outer disks, pull the 120cm-long wire 26cm past the inner disk so that it will reach the forward battery terminal after passing through the battery tube (which will be attached later).

With the wire extending 26cm from the inner disk, cement the middle and inner endcaps together (photo 3).

Sand (something around 150 grit) ONLY ONE inner surface of each battery tube. This end will be the side that the aft (spring terminal) endcap assembly will be permanently attached too. (The other end must stay smooth so that the o-ring on the other endcap will seal against it)

Place the aft endcap assembly into the sanded end of the battery tube. The fit will be snug. If you find it too hard to get the endcap assembly into the tube, you can use sandpaper to taper the edge of the endcap assembly to help guide it in straightly.

A small amount of acrylic cement can be applied between the rim of the endcap and the battery tube. Although the two parts are different types of plastics (so the cement won't bond well), it should soften both pieces to create a seal that will help prevent epoxy from leaking out during potting (which will be done later).

Once you've done this for both battery packs, you can set them aside (for the time being)

We're now going to build the endcaps for the electronics tube of the ROV.

Start out by removing the plunger from both syringes. We're going to cut the syringe tubes in two locations.

Make sure to set aside the plunger in a safe place as this is needed to seal the electronics tube.

Cut the syringes with a hacksaw just above its plunger stop as shown.

Then cut at the .16 mL mark as shown.

Use medium grit sandpaper to smooth the edges and square them up.

Using a razor, you can debur the inside edge of the syringe section, but be careful not to make any large gashes along the inside surface!

Remove any grit or dust left inside.

Now we're going to start cementing the endcap disks together.

Peel the backing from the acrylic and clean the disks.

Place the 6mm disc on top of the 3mm disc.

Insert the syringe so that the end with the plunger stop is facing down and is flush with the bottom surface of the 3mm disc as shown.

Make as much surface area between the two discs cemented.

A good technique for cementing the disks together is to insert the syringe needle between the top of the two disks while pinching the bottom as shown.

Allow cement to flow between the two disks so that it fills the gap between them from the bottom, up. (You may want to wear gloves, as some cement tends to leak out the bottom). Fill until the cement is about half way, then remove the syringe and squeeze the disks together so that cement is pushed across the entire interface between the disks.

You may want to rotate the disks about each-other slightly to spread cement around, but be sure that the two holes toward the edges of the disks are aligned before the cement sets.

Extra cement that drips out from the disks can be blotted up with a paper towel.

Make sure the cut syringe is flush with the surface of the inner disc (the 3mm disk).

Cement it in place if it isn't already.

Do the same thing for the other syringe, 3mm disc and 6mm disc.

You should now have two identical parts as shown.

Next, find the two 1.5mm clear discs with the flat edge.

Orient the flat edge towards you and place each one on top of the endcaps as shown.

The edges have been marked with blue to show the orientation.

Use the same technique as before to cement the 1.5mm disc to the 6mm disc.

Make sure the inside circle and the syringe are concentric as shown.

Now find the 6mm disc with the cut out.

Place them on top of the newly cemented 1.5mm disc.

Orient as shown. The edges have been marked in blue for clarification.

Try to keep the 6mm disc with the cut out concentric and cement it to the 1.5mm disc with the same technique as before.

After all the discs have been cemented together, allow a little more cement to run around the perimeter of each gap to make sure all the edges of the discs are well joined.

Congratulations! You have completed most of the electronics tube endcaps. Now, we'll check to see if they fit well in the main tube.

In these steps, we'll check that the endcaps make a good fit in the Main Tube.

Start out by beveling the inner edge of the main tube using a medium grit sand paper so that the o-ring will fit in the tube without getting damaged by the sharpness of the tube's inner edge. Wipe off all the dust left over from the sanding process when done.

We'll now place syringe plungers into the holes for each main endcap. These plungers seal the endcaps during use, but can be pulled out momentarily to relieve pressure after the endcaps get seated (which pressurizes the air inside the main tube)

The stem of each syringe plunger should be cut so that it is flush with the outer surface of the endcap as shown. (This way it will be held in place when the main tube is placed inside the shell of the ROV)

Place a #340 o-ring (the medium-sized, fat one) in the grooves ("o-ring glands") of both endcaps

Since the o-ring will make a pretty tight fit with the main tube when pushed out to the right diameter, it is recommended that a lubricant be used on top of the o-ring (we like to use a commonly available lubricant called "MagicLube" which is available at many hardware stores) to assure the o-ring gets seated properly

Place both endcaps into the main tube, and inspect to make sure that at least a 1mm-thick band of the o-ring is pressed against the inside of the main tube. Rotate the tube to make sure the o-rig engages along the entire interior perimeter of the tube.

VERY IMPORTANT: Because the tolerances of the pieces may vary slightly, it's possible that your endcap may not engage tightly enough with the main tube. (You can see an example of what this looks like in the second image).

Once you've tested the fit of your endcaps, put them in a clean place (like a zip lock bag) so dust and particles don't get on the o-rings.

Now we are going to arrange the motors in relation to the mounting base.

Start by removing the two set screws at the base of the motor.

Find the motor that comes off of the base the easiest and mark this one and use it as your vertical motor.

Rotate the motor in the base so the wires are coming out directly to the right of the screws, as seen in the third picture.

Insert the set screws back in and tighten them.

Attach the motors to the inner structure using M2 screws, lock washers, and nuts.

It is easiest to mount the vertical motor first. The motor leads should go to the left of the upside-down internal structure (which will actually be the right or "starboard" side of the right-side-up ROV.

The vertical motor should be the one that comes off the base the easiest (you should have it marked from an earlier step). Make sure when you are positioning it that the set screws are in the positions shown.

When attaching the horizontal motors make sure the M1.5 set screw is in an accessible position in case it needs to be adjusted later.

Now take the six auxiliary wires (each is 1 meter) that you cut earlier and mount them to the frame underneath the forward/backwards motors with a zip-tie.

Insert the internal frame into the outer shell, and using four large reusable zip ties, mount the battery tubes as shown.

Label the three-wire bundles coming from each motor. We use "P" for the port (left when upright) motor, "V" for the vertical motor, and "S" for the starboard (right when upright) motor.

Now label each of the battery packs. (We use "BP" for "Battery- Port" and "BS" for "Battery- Starboard". You'll also want to trace the longer wire on each battery pack (the one that goes all the way to the front of each tube) and label them "BP+" and "BS+", respectively, so that you can later identify the polarity of each wire.

Now we are going to do some wire management.

Strongly consider uncoiling the tether at this point to relieve its residual torsion so you can more easily unwind it during deployment. Follow these steps. It's easiest to do this before the tether is connected to the OpenROV, though you can also defer it and do it after.

First take the tether wire, the twisted pair of two colors, and run it so its length matches that of the wires connected to the motors. It should run in the middle by the handle, as seen in the picture.

Secure all of the wiring bundles with zip ties as shown. You can find small zip ties in the boxes for the Electric Speed Controllers. (Note that in this image, you can see I decided to point the bundle coming from the starboard motor downward instead of its original orientation where it was pointing to the left)

The collective bundle of wires (we'll call it the main wiring harness) should snake around in a loop as shown. This will make it so less precise measuring is needed when running the harness through the endcap, and will also allow for motors to be replaced more easily in the future.

Now we'll cement the shrouds in place.

Place one of the shrouds against the supports as shown. You can hold it in place with your finger.

Add acrylic cement to the points indicated in the picture.

Do the same for the other shroud.

Before routing the yellow mesh count the wires that you have in your bundle. There should be a total of 21: 9 motor, 4 battery, 6 auxiliary, and 2 tether.

Now we're going to route the yellow mesh sleeve material over the main wire harness. The sleeve material expands when it is compressed much like how a finger trap works.

Start by wrapping tape around the ends of all the wires in the main harness as shown. The purpose of this is to prevent the sleeve material from getting snagged as it is placed over the harness.

If only a few individual wires are left sticking out of the tape, and their labels are further down the wire, those ends can be snipped off.

Push the sleeve over the main wiring harness and slide it all the way down until its end goes past the bulkhead of the internal structure.

To keep the sleeve material from fraying (beyond what it will have already done while putting it on) wrap both ends with electrical tape where the fraying stops.

Add one non-locking M5 nut to each end of each threaded rod, about 1cm in from each end.

Insert one threaded rod into the rear-most set of holds on the bottom of the shell and the other rod either all the way forward, or the second hole in from forward.

Placing the rod in the furthest-forward set of holes is best for ROV balance and strength, but may interfere with the field of view of the camera later on. It's easy to switch this if you change your mind!

Attach locking nuts to the ends of the threaded rod. The locking nuts are the ones with the white nylon inserts inside of them instead of just being all metal.

To prevent your ROV tether from getting twisted in the motors add a zip tie to the circular hole in the handle at the back of the ROV. Do not cut the zip tie.

Wrap the ROV tether around the zip tie.

Wrap the zip tie and tether with electrical tape.

Now that your ROV is complete, take one of the OpenROV stickers and place it on the back of the ROV!

Use scissors to cut off left over frayed ends of the sleeve material up to the electrical tape.

Thread the wiring harness through the Port endcap. The harness should go from the outside of the endcap, inward. You can make sure you're going through the correct endcap by placing it in the position as shown. In this position, the flat edge of the endcap should face toward the port battery tube.

During this step, we'll measure out the right length of the wiring harness so that it is not too tight or too loose when the end cap is in place. Adjust your wiring harness and end cap so that they resemble the photo above.

Once the tension of the main wire harness looks good, you can cement the white endcap cover onto the endcap. Be sure the endcap cover is pressed firmly against the endcap near where the harness passes through the assembly.

You'll also want to cement the other white endcap cover onto the other (Starboard) endcap.

Apply hot glue around the part of the endcap the wire harness enters through (the side with the rectangular opening- not the side with a circular opening). This hot glue will form a barrier that will prevent epoxy from leaking out when the endcap is potted.

The other (starboard) endcap can also be prepared for potting at this time. Create a barrier of hot glue at the end of the endcap channel to hold the epoxy in.

Apply a glob of hot glue to the end of each of the six auxiliary wires, then after each glob has hardened, bundle the ends together and apply hot glue to the bundle.

Now, we're going to prepare the endcap to be potted. To start, we'll want to bundle the wires coming out of the endcap together.

We'll also pot the two battery tubes during this period. The tubes can be dangled over the edge of a table from the internal structure as shown (so that the epoxy they are potted with doesn't flow out the hole it is injected into)

You can now start potting the endcap. It is important that all the gaps between the wires in the harness get filled with epoxy. When potting the harness, periodically insert the epoxy nozzle between random sets of wires and move the tip of the nozzle around. Also be sure to inject epoxy under the channel the wires pass through in the endcap.

To help remove voids in the epoxy filing the endcap channel, move the harness up and down (like a toilet plunger) and from side to side. This may cause the level of the epoxy to fall (as it fills voids). More epoxy can be added as needed.

Now we pot the aft battery endcaps. To do this, we'll insert the nozzle from the epoxy cartridge into the small hole on the edge of the endcap. Injected epoxy should flow in both directions around the perimeter of the endcap, then into the channel leading toward the leadwires and out to the channel's two ends. Some may also ooze out the center.

Finally, you'll also want to fill the hole of the Starboard endcap with epoxy. Just as for the Port endcap, epoxy should come up to just below the rim of the endcap hole.

If you have epoxy left, you can apply some to the shroud as shown in the picture for added strength.

While the potting on the endcap and the battery tubes is drying, we are going to move on the the electronics.

The first step is to build the Electronics Chassis (also known as the E-Chassis). For this, you'll need the 15 parts shown here (note that if you are building from a kit, the two crescent-shaped blinder pieces in the lower right of the photo may be in a different bag)

The relationship between the sides and the main plate has a certain orientation as seen in the second picture.

Attach the four Braces (two for each Endplate) to the E-Chassis and the side pieces and cement all in place. Also make sure to glue the side pieces to the main platform.

Next, cement the Servo Mount to the same side of the Main Chassis the Braces are on.

Now we'll start making the camera platform. Start by cementing the two pieces for the Camera Mount arms together. The round bases of each piece should end up being concentric, but to aid with cementing, it may be easier to stagger the pieces initially. Of course, be sure to align them before the cement sets!

Next, you'll want to cement the Camera Mount arms to the Camera Platform with the smaller of the two pieces on each arm facing outward (make sure to double check that you have it correct).

When cementing these in place make sure they are at a 90 degree angle to the main piece.

Finally, attach the white blinders to either side of the camera hole.

Now it's time to attach the ESCs to the OpenROV Controller Board. In each ESC box, you'll find one ESC, two zip ties (which you probably used earlier), and a bag with shrink tubing and double-sided adhesive. You'll want to keep the zip ties and bag, so put them aside for now.

We'll want to cut the thick lead wires from the ESC down in preparation of stripping and tinning the wires. Cut below the colored heat shrink first, then cut the power and ground wires to similar length.

Next we will want to strip and tin the wires. Here is a quick tutorial on how to do both like a pro. Practice on spare white wire you might have first to get the hang of it. http://www.instructables.com/id/Strip-an...

Strip wires 4.5cm from base exposing as much wire as possible WITHOUT removing the insulation entirely just like the tutorial mentions. Then tin the wires.

You should end up with five wires that have been tinned throughout most of the exposed wire.

Now we will solder the ESCs to the controller board. Place your wires through the appropriate holes. Place the controller board on an ESC box to keep it level with the length of the ESC wires you'll be soldering.

Solder on the wires to the board.

Cut off any excess wires with diagonal cutters once done soldering.

Now you have both parts of the E-Chassis and a controller board that's ready for external electronics. Nice job! Next, we're going to attach the lights and camera to the Camera Platform.

Start by soldering the two light panels together. To do this, you'll want to create a small solder blob on the pads on the far left and right of one of the light panels, then attach the leads from the other light panel so that the red wire you're attaching is on the same side as the red already-attached wire (and the same for black).

Apply a small amount of super glue between the two notches in the Camera Platform and place a light panel there. The light panel should be positioned so that its leadwires are aligned with one of the notches, and it should be centered vertically.

Now you'll want to take apart the Genius F100 webcam so it can be mounted to the Camera Platform. Start by pulling the camera off of its stand (a strong tug should do the trick)

Next, remove the plastic piece still attached to the camera by unscrewing the small Phillips-head screw that goes through it.

Using small zip ties (you'll have found two of these in each box the ESCs came in), attach the webcam to the Camera Platform as shown. You'll need to double up the zip ties in order for them to reach around the assembly.

You can use scissors or a diagonal cutter to remove excess zip tie material. You'll want the zip tie heads to be positioned so that they don't bump into the E-Chassis main platform when the Camera Platform is looking all the way up or all the way down.

Once everything is secure, you can set the Camera Platform assembly aside for later.

Now we will work on the ROV side Ethernet conversion.

First, pry apart one of the Homeplug adapters using a flathead screwdriver. It's easier to pry using a twisting motion then a lever motion. Keep in mind that one of the four walls of the enclosure is attached to the top piece, so prying wont work on that edge.

Once you've opened the Homeplug enclusure, pull the top circuitboard (the one with the power wires going to it) off of the communication board below it. You can discard everything but the communication board.

Attach the ethernet jumper (the one that came in your electronics bag, not the one that came in the Tenda box) to the communication board as shown.

Place the communication board on the controller board using two 6-pin reciprocal headers. With the ESCs mounted, it will be a tight fit go get everything on, but with a little finagling, it will all fit.

Attach the nylon standoff to the hole toward the center of the controller board using a nylon M3 screw as shown.

Lay the ESCs down on the Controller board as shown. You should be able to tuck the capacitor for each of them under the wires to keep them out of the way.

Plug the other end of the Ethernet jumper into the BeagleBone Black as shown. Ultimately, the Ethernet jumper wire will snake around the side of the Homeplug adapter board near the standoff.

Press the BeagleBone Black onto the extended header set on the Controller Board as shown. Make sure the header pins on each board are aligned with each-other properly!

Secure the BeagleBone Black to the nylon standoff using an additional nylon M3 screw.

Make sure the PWM wire and the switch for each ESC is accessible as shown in the last picture

Attach the Controller Board to the E-Chassis using M3 nylon screws and nuts as shown. To orient the board, assure that the three rectangular cut outs on the E-Chassis are aligned with the three groups of solder joints from ESCs on the Controller board.

Take the two-arm servo control horn (in the same box as the HS-81 servo) and cut off one of its arms using a diagonal cutter.

Also use the diagonal cutter to remove the corners from the cut-off portion of the horn. This will allow the arm to fit inside the hole cut out in the Camera Mount arm.

Before mounting the servo to the E-Chassis, make sure the horn (white plastic part) is centered.

To do this gently rotate it back and forth to its extreme left and extreme right. You can remove the horn and then adjust how the horn is placed on the servo so that it centered between the extremes. (see diagram).

Loosely attach the servo to the E-Chassis using a set of M3 screws and nuts as shown. You'll need the nuts to be just barely threaded onto the screws at first so that the Camera Mount arms can be put into position before being secured. (Make sure the arm is centered - lined up with the camera mount semi-circle.)

Place the Camera Mount Assembly onto the E-Chassis so that the top of the webcam (the side without the webcam mounting stand tabs) is facing up with servo on the right when the camera is facing toward you.

Attach the arm on the side without a servo to the E-Chassis using an M3 screw and nut.

After assuring the servo arm is seated inside the cavity of the Camera Mount arm, tighten the two screws holding the servo in place until they are snug.

Plug the servo and ESC plugs into the J20 and J21 headers as shown. The signal wires from each (the white wire on the ESCs and the yellow wire on the servo) should face inward.

The Port ESC (the furthest ESC from the J20 headers- labled as ESC-1) should plug into D6, the Vertical ESC (the middle ESC, labled ESC-2) should plug into D7, and the Starboard ESC (closest to J20) should plug into D8. The servo should plug into D11

The black and red leads from the lights need to be attached to the controller board. The connections should be at J1 with the black wire going to P1- and the red wire going to P1+.

Now is a good time to update the firmware on your Beaglebone. If you bought the OpenROV kit from our webstore, the Beaglebone has an image pre-loaded onto it. This image, while functional, may have a more current version that is available. This is an optional but recommended step.

The newest BeagleBone image is found on Github. Follow the link and directions HERE.

Next, you can plug in the USB connector for the webcam. You'll want the cable from the connector to bend in the direction toward the DB-25 plug.

To keep the USB cable for the webcam out of the way, we'll wrap it around the main platform of the E-Chassis. Because the Electronics Tube will have to fit over the entire assembly, it's important that the wraps of cable are side-by-side and do not stack on top of each-other.

Depending on where the end of the doubled-up cable ends up (that seems to vary every time we build an E-Chassis) you can use the velcro strip that came with it, some tape, or a small zip tie to hold it in place.

The resulting bundle should lay flat against the E-Chassis platform, but be pushed to the side enough so that when the camera platform is pointing all the way up or down, the camera doesn't collide with the cable.

Now that the epoxy in your endcap has had a little time to cure, we can get ready to add the DB-25 connector to the end of the wiring harness that passes through the endcap.

Start by removing the tape that was used to hold the bundle together.

Next, measure a distance of 17cm from the inside surface of the endcap, and cut one of the wires from the bundle at that length. Measure twice, cut once- you don't want the harness to be too long or too short by more then about 1cm! Before you cut the wires make sure that the labels are below the cut line.

Use the one wire that you've cut as a guide to cut all the remaining wires in the bundle to the same length

Now you can get ready to solder the DB-25 connector to the end of the newly trimmed wire harness.

Start by stripping off about 3mm of insulation from the end of each wire. If you strip off too much the wires can make contact and cause the system to fail.

Because each stripped wire will just barely fit in the solder cups for the DB-25 connector, it's easiest not to tin the wires before inserting them into their respective positions.

Look on the back of the DB-25 connector (the end with the solder cups) and identify pin 1 (labeled with a faint imprint in the plastic for the connector).

Use the guide shown to attach wires to the DB-25 connector. Be sure that battery polarity is correct by measuring for continuity between the forward (positive) terminal in each pack and the other end of the wire it goes too.

There should be four pins that are left empty (TP22-TP25).

Now, we're going to build the "Topside Adapter" box which will convert your two-wire tether back into standard Ethernet which can be plugged into your computer.

Start by removing the communication board from the Homeplug adapter in the same way as shown for building the E-Chassis. The Homeplug Communication Board and Adapter Board mate together as shown.

It is possible to put the housing for the Topside Adapter backward. To avoid this, start out by doing a test fit with the pieces shown to make sure the Ethernet and USB jacks are aligned with their respective holes on the housing wall.

Cement the three pieces shown. Be sure the long, skinny side panel is cemented with the flat side facing away from the side with the Ethernet and USB holes

Once the first set of three panels has been cemented, the other set of three can be put together.

Now that the two side-panel assemblies have been cemented, the paper backing can be removed, and the pieces can be slid together.

Tape can be used to keep the pieces from coming apart. Make sure the tape is towards one side so you can still see the lights in the middle of the board.

Attach the topside adapter to the other end of the tether.

Start by stripping the ends of the twisted pair.

While holding the orange tab in the rear position, insert the bare copper of each of the tether wires into the green circular holes.

Let go of the orange tab to secure the tether wires in place.

If you have an ROV with a serial number less than 1400 then follow these steps. If you have an ROV that is 1400 or greater then move to the next step.

Next, we'll glue the disks for the forward endcap. For this step, we're going to use a motor shaft as a centering pin.

Slide the larger forward endcap disk (28mm diameter) over the motor bell. Then slide the smaller one (24mm diameter) on. It will be a very tight fit.

Take another large forward endcap disk (28mm diameter) and sandwich the smaller 24mm diameter disk. Cement it in place.

Attach and cement the outer forward battery endcap disk (the one that is has the two notches on the outside).

Sand a corner of the button terminal (any corner of the button terminal - on button side).

If you have an ROV with a serial number that is 1400 or greater, then follow these steps. If you have an ROV that is less than 1400 skip this step as you assembled your front battery endcap in the previous step.

We'll glue the disks for the forward endcap. For this step, we're going to use a motor shaft as a centering pin.

Start by sliding the outer forward battery endcap disk (the one that is has the two notches on the outside) onto the shaft.

Next slide on the smallest disk (also the thickest) onto the shaft and cement it in place.

Finally, slide the forward endcap disk (28mm diameter) over the motor bell and cement it in place.

Sand a corner of the button terminal (any corner of the button terminal - on button side).

Using the same method as for the spring terminal, apply a glob of solder to the sanded area of the button terminal.

Sand the bottom of the button terminal as well as the surface of the endcap that it will be bonded to.

Using superglue, fasten the button terminal to the forward endcap assembly (it should be against the circular endcap disk, not the flange disk that has nubs on it)

Using a medium grit sandpaper sand the front edge of the endcap in order to add a chamfer. Make sure not to sand the grove where the o-ring will sit.

The next time you are using epoxy (you'll need to use it to attach the propellers to each motor bell, and to pot the outside cavities of the endcaps), you'll also want to fill the alignment hole on each battery endcap with epoxy.

While the epoxy is still fluid, you'll want to attach propellers to the motor bells for each thuster. Start by sanding the shaft of each motor bell using a medium-grit (we used 150-grit) sand paper.

Cut off three 8mm long pieces of the adhesive-lined shrink tubing that was also used on the motor leads. These will be used to keep the shaft concentric with the mounting hole in the propeller.

Slide one of the pieces of shrink tubing down to the root of each shaft and shrink it down until it is secure using a heat gun.

We'll now do our second set of potting

The first thing we'll pot is the two forward battery endcaps we just built. To do this, simply place the nozzle of the epoxy cartridge into the top of the alignment hole and inject epoxy into the hole until you can see it spreading out across the bottom of the button terminal.

Sometimes enough of a seal is created around the button terminal that pressure will build up and push epoxy back out the alignment hole after it is injected in. If this happens, use a small wire or toothpick to sort of 'plunge' the epoxy back and forth to fill the hole.

Next, we'll also fill the back side of the main endcaps around the protruding parts of the syringe sections.

Be careful not to allow epoxy to over-flow into the hole of the syringe as this will need to be clear for the syringe plunger (which acts as a pressure relief valve)

The last thing we'll apply epoxy to is the propellers (which each get mounted onto a motor bell).

Place the tip of the mixing nozzle firmly into the hole of a propeller and fill the hole with potting compound until it overflows. There may be some air that needs to escape for the potting to fully fill the hole. It's okay for some potting to overflow onto the surface above the hole.

Using a rotating motion, press the propeller down against the motor shaft. You'll need to sort of screw the threading onto the shrink tubing on the shaft for it to go on all the way without scrunching the tubing.

Do these steps for all three motor bells and place them somewhere where they can point directly upward. A wire shelf or a crack made between two books can allow the bottom side of the shaft to be out of the way.

If you have an ROV with a serial number of 1400 or greater, you will have three propellers that are all different.

Add a chamfer to the front inside of the battery tubes. Using a medium grit sandpaper sand the inside edge.

Attach the forward battery terminals to each battery pack. This will be done in a very similar way to how the rear spring terminals were wired.

Using pliers (since the wire will likely get quite hot) hold the wire lead against the solder blob on the battery terminal and heat the terminal until it accepts the wire.

Hold the wire in place with the pliers until the solder cools and hardens.

This is a good point to trim off excess hot glue from around the main endcaps so that they engage with the main tube cleanly. Use pliers or a razor blade to remove any glue that will keep the inner surface of the endcap flange from mating with the edge of the main tube.

Now is a good time to talk about which batteries you plan on using for your OpenROV. We recommend the Batteryspace Li-FePO4, which are available on our webstore.

If you plan on using other batteries such as the Trustfire 26650 Li-Ion, you can skip this step.

If you plan on using the Batteryspace Li-FePO4, you will need to build a battery tube adapter. The how-to on this is found HERE.

The two battery packs are wired in parallel to the OpenROV Controller Board.

Place three fully-charged batteries in each tube, positive end forward.

Take the o-rings for the battery tubes and apply a small amount of lubrication to them. Then slide them over the front of the endcap.

Close the tube and secure it with an extra 157 O-ring.

Using a digital multimeter, measure the voltage across each battery tube at the DB-25 connector. You should have around 12 volts dc.

The batteries can be left in the battery tube safely and without being drained because the OpenROV is turned "on" by plugging the mini-USB cable into the Topside Adapter. (We will do that later).

You can also now attach the motor bells with propellers to their motors. You want the two aft props to be counter rotating. Make sure when attaching the motor bells that the inside magnets are free of debris for this can prevent the motor from spinning smoothly

If you have an ROV with a serial number less than 1400 then follow these steps. If you have an ROV that is 1400 or greater then move to the next step.

Your vertical propeller will be the one that you have left over. If it is not moving in the correct direction, you can reverse it in the cockpit settings under the "Diagnostic" panel.