Please Note: These instructions are a work in progress.

Components:

Your kit should come with the following components:

1. A Printed Chassis in your chosen color. 
   
   1. This may be on a “raft” (it connects the whole sheet of components together) The parts may also already be fully separate and ready to go.
   2. It should include 4 parts: The main chassis, A chassis lid, A wedge module, and a Wedge plate (note, in the newer kits we now include a heavier, TPU wedge plate, which will be more durable in combat)
      
      
2. A Battery
   
   
3. 2x N20 DC Gearmotors
   
   
4. A package containing 2x wheels. These may be the Pololu wheels below, or the newer Pyre Robotics PU wheels which are white, and have better traction (photo coming soon)
   
   
5. A package containing a Kakapo (the internal bot controller)
   
6. A package containing a pair of N20 Faceplate Mounts
   
   
7. A small baggie containing a few M3 Machine Screws (There should be 2x 10mm, 2x 25mm, and 4x nuts, as well as 2 more 6mm)
   
   
8. 2 Packages of JST Power Connectors
   
   

Required Tools

You will require a few tools and supplies to finish the build of the kit:

1. A small phillips screwdriver
2. A set of small metric allen keys/hex wrenches
3. A soldering iron
4. Some fine solder
5. A solder flux pen or flux paste (not absolutely required but helpful)
6. A small pair of wire snips/cutters and/or wire strippers
7. A small pair of tweezers, or fine tip needle nose pliers
8. A small needle file, or nail file (not absolutely needed, but useful for cleaning/adjusting fit on parts)
9. A Heat Gun (hot air gun), Hair Dryer, or a heat source such as a lighter, etc, for shrinking heat-shrink tubing. OR if these are not available, some electrical/sparky tape for protecting components once assembled.
10. Safety glasses

Additional Required Parts to use the Kit

You will also need a few additional bits to be able to the kit, these items are not included with the kit:

1. An RC Transmitter, which can communicate to an ELRS Receiver (or alternate if you've chosen a kit with a different receiver).
1. CRNZ Sells the RadioMaster Pocket Transmitter, which uses ELRS and will work out of the box with these kits
2. A Lithium Polymer Battery Charger
1. The charger needs to have a JST Connector, and must support charging a 2Cell LiHV or LiPo battery cell. CRNZ Currently sells affordable chargers which meet this requirement
3. A Lithium Polymer Battery Charging Box or Bag
1. This should be a fireproof container specifically designed for charging lithium batteries, and is an important safety consideration.
2. In a pinch, a simple steel tool box, or other non-flamable container will be sufficient for the small batteries in these kits.
3. Never leave lithium batteries unattended while charging

Build Steps

This procedure does not need to be followed in precise order, the steps are meant as a guide, to help you complete the build, but part of the fun of building a Combat Robot is figuring out how it goes together, and trying new things, so there is plenty of room for you to do your own thing, or try assembling in different order, etc.

It is recommended you read ALL these steps completely first, before starting. 

Preparation Steps

These steps are useful to prepare parts for assembly before going into the assembly in earnest

Prep the Chassis

Preparing the chassis will allow you to verify the chassis print is cleaned up, and ready to accept the other parts. Also to dry fit the components together to get a feel for how they fit together.

Because of the nature of 3D printed parts, it’s possible that some tolerances may be slightly out, resulting in some fits that are too tight, or too loose, or holes that are partially filled, etc.

Even if the chassis you received is already separated (not on a raft) it is still worthwhile to inspect the parts and ensure everything fits together.

1. You should wear safety glasses/goggles for this step, as small plastic bits may break off into the air, causing an eye injury risk.
2. First, if your parts are on a raft, you must remove the parts from the raft.
1. If you look closely, you will see the raft is made up of 2 layers. The very bottom layer is more coarse, almost a mesh, and the next layer is smaller (closer to the perimeter of the parts) and a bit more dense.
2. The raft should literally “peel” away from the parts like a sticker. Do this carefully, careful to peel slowly, and not damage the parts (the raft is sacrificial, damaging it is ok)
3. If any parts of the raft stick too strongly to the part, you can use some flat tool (a thin file, screwdriver, tweezer tip, etc) to wedge in between the part and the raft, gently pushing and twisting to work the raft apart slowly. 
4. It can be helpful to start with the larger main chassis first, as it’s the most sturdy/stable of the parts, and the raft should come off it most easily. This can let you get a feel for how the raft separates first, before working on the more delicate parts such as the wedge, or lid.

1. Once the parts are removed from the raft, each should be inspected for excess plastic in the holes, or openings.
1. Look for extra strings or stray filaments which noticeably stick out, and carefully remove them
2. Try dry-fitting the parts together, to see if things fit. If they don’t you can clean up a bit with a file, snips, or tweezers to clean up as needed until things fit well
3. Parts should be snug without requiring too much force to assemble. They shouldn’t fall apart on their own, but also shouldn’t require excessive force to disassemble.
2. Do a final dry-fit assembly of the entire chassis, including using the M3 Screws, and confirm you are happy with the fit
   
   
1. The 2x 10mm screws are used to secure the wedge plate to the wedge module.
   
2. The 2x 25mm screws are used to secure the lid to the chassis
3. 2 nuts go into the recesses on the bottom of the chassis, these can be secured with a drop of superglue if needed, or left loose, this is up to preference
   
   
4. 2 more nuts are recessed into the angled channels in the bottom of the wedge module to retain the plate.
5. It can sometimes be helpful to use one of the 25mm screws as a "handle" of sorts, thread it a few turns into the nut, and use that to place the nut correctly, then unthread the screw when done. Or you can use tweezers to fit the nuts into the angled recesses first, then use the screws to tighten them into place once they are aligned properly.
   
   

This is what the final assembly should look like at this stage:

Prep the drive modules

The motors get mounted to the Faceplate Mounts by soldering. It is helpful to complete this step on it’s own as it can be time consuming to get the soldering technique right.

1. Open the package of faceplate mounts, and remove the mounts, and their fasteners.
   
   
2. The faceplate mount attaches to the front of the motor, there is a tiny collar/lip around the shaft of the motor which should fit perfectly into the centre hole on the faceplate mount.
   
   
3. Temporarily screw the plate onto the motor
1. With the shaft in this hole, there should be 2 more holes which line up with screw holes on the motor. One of these holes will have gears close behind it, the other will have a larger gap. 
2. You may have a version of the faceplate mounts with longer or shorter screws. If you have the one with several short screws, then skip this step. Otherwise, Attach 2 nuts and thread them all the way onto one of the M2 screws. These will act as a spacer
3. Use 2 of the M2 screws to attach the plate to the motors using the one with the nuts/spacer on the side with the closer gears (if you have the one with the longer screws, as this will allow you to tighten the screws down without damaging the gears with the screws).
4. The screws don’t need to be tight, just snug.
   
   
4. Place the mounting plate in some kind of tool to secure it in place allowing you to work, oriented so it is parallel to the ground, with the shaft of the motor pointing down and the body of the motor pointing up
5. Locate the copper pads which align with the edges of the front brass plate of the motor gearbox. 
6. If you have any flux available, it can help with this step, apply a bit to the motor plate around the edge (do not get any in the gears), and on the copper plate on the PCB.
7. Set your soldering iron on high (or if it has a temperature setting, a high temp like 400C is helpful) and let it pre-heat
8. Ensure the tip of the soldering iron is clean and tinned
9. Heat the pcb and motor along the edge, it helps to get the soldering iron in the “valley” formed by the lip of the motor along the pcb, so it is contacting both parts with as much surface area as possible.
1. Note: the motor can absorb a lot of heat, it will make heating this joint adequately difficult, and may take a bit of time
2. It can help to have a bit of melted solder on the tip to increase the surface area in contact with the parts.
10. Keep trying to apply the solder to the PCB and motor at the joint, once it is at an adequate temperature, the solder should melt, allowing you to effectively solder the joint.
11. Repeat this for each corner of the motor, so that it is sufficiently soldered down.
12. Be careful not to apply too much solder, you don’t want a lot of blobbing. Just enough to firmly hold the motor in place, see the photo for an example.
13. Be careful at this point as the motor and plate will be very hot to the touch and may burn you. Do not touch it with your hands until it’s fully cooled.
    
    
14. Repeat the entire process for the second motor.
15. Let both motors cool fully
16. Install the Wheels on the motor shafts
1. Open the package of wheels
2. Carefully snap the tyre onto the rim
3. Press the wheel (with the protruding side of the wheel hub sticking towards the motor) onto the D shaft of the motor. Ensuring you leave a couple mm of clearance between the faceplate and the wheel
   
17. You have now assembled your two drive modules

Prepare the wire lengths

It is helpful to prepare the lengths of wire you’ll need so you can easily assemble the circuits later in the process

Note: When referring to JST connectors, the Male Connector is the one which has an outer housing and 2 pins inside, while the Female Connector is the one which plugs into the male (it has 2 holes which the pins go into, but the plug itself fits inside the male).

1. First open one of the packages of JST connectors. The Male connector will be used for Battery Input, and the Female for Power Output (to an ESC for a weapon module). From both the male and female wire, cut a length off the wire that is approximately the length of the back of the bot chassis (slightly shorter is ok, but not too short). As shown:
   
   
2. You should now have leftover a pair of connector ends that are approximately this length (depending on exactly how long the wires in your kit are, it's ok if your connector ends are slightly shorter):
   
   
3. Strip off about 5mm of each exposed wire end (both ends of the long pieces, and the wire ends on the connectors), then tightly twist the exposed wire so that it is neat (no fray wire strands sticking out).
4. Now we will "Tin" the tips of these wires, which will make soldering easier in later steps. This basically means we'll pre-apply some solder to the exposed wire.
   1. First heat the soldering iron up until it readily melts the solder if you touch a small amount of solder to the tip.
   2. Clean the end of the soldering iron so the tip is clean, and then apply a small amount  of solder to it, which will help heat transfer.
   3. Now, with the wire held securely (preferably not in your fingers, as the wire may get hot), apply the soldering iron to one side of the wire to heat the wire up, then gently touch the solder to the other side of the wire, when the wire is hot enough the solder should melt into the wire readily like water being soaked up in a wick.
   4. When done, your wires should look something like this:
      

Main Assembly Steps

Assemble the Kakapo/Wire Harness

1. First open up the Kakapo package, and remove the protective foam (if present):
   
2. Once unwrapped, the Kakapo should look like this (the one shown here has the pre-soldered ELRS receiver attached, there are other variants as well, but this is our default for the kit):
   
   
   
3. The Kakapo should be secured in something suitably heat resistant. In these photos I'll be using a "Helping Hands" which is an articulated set of alligator clips, but anything that holds it securely in place so you can work with both hands will do. At this stage it should be secured with the back side (With the text showing Kakapo 2A and the labels on the solder tabs showing, but with the other side accessible as well if possible)
4. We're going to start with the far right side Motor 1 connection (labelled M1). Start with one of the black lengths of wire with both ends stripped, and insert the end of the wire up from the other side through the hole in the right most pad as shown:
   
   
5. It should have it's insulation flush against the bottom, and stick up a couple mm above the top facing side as shown above. You can apply a bit of a bend pulling the wire slightly towards yourself to keep it secure in the hole. Ideally this should be able to stay there on it's own (if you can hold it with something, in my case I used one of the other clips on my helping hands for this step).
6. Now using the hot soldering iron, apply the tip in a way it tries to fold over the end of the wire, holding it against the side of the hole and into the pad if possible as shown: 
   
7. Now that heat is being applied to the wire and pad, gently touch the end of the solder to the pad, to apply some solder. It should flow freely onto the pad and into the wire, creating a strong joint that looks something like this:
   
   
8. Now using the same technique, let's add one of the red wires (of similar length) to the next pad (the one labelled M1), and the result should look like this:
   
   
9. Now we'll move onto the battery input. For this we'll use the Male end of the JST connector that we prepared earlier. For this process, take special note that you have the correct connector (Male, not Female, see earlier note about telling them apart for JST connectors... Male has the pins in it). Also note that the order of the wire is opposite for the battery input. So we'll start with the red wire on the right, then the black wire on the left, using the same technique we just used for the prior 2 wires:
   
   
10. Now we'll move onto the Weapon Output, this is the connector that we will plug another ESC into if we're using a weapon module. It passes through battery power, switched by the main power switch. For this we'll use the FEMALE JST connector, this is the one without the pins. It uses the same wire ordering that the battery input does. Let's start with the red, then the black wire, using the same technique as we have been using for previous wires:
    
    
11. Lastly, we'll now add the other motor's wires, using the last 2 lengths of wire we prepared earlier. First we'll start with the red wire, putting it on the right hand side tab labelled M2, and then finally the black wire to the leftmost (and final) tab. Again using the same technique for these:
    
    
12. Your finished Kakapo wire harness should look something like this:
    
    
13. At this stage it's useful to coax the wires into a slightly different position as they will need to be to fit into the chassis (bending the M2 and Weapon Output wires 90 degrees to the left when looking down on the top of the kakapo, keeping them as flat to the kakapo board as possible):
    

Connect the Drive Modules

1. Connect the two assembled Drive modules to the kakapo circuit by soldering the free end of the Motor Wires onto the terminals on the motor.
2. Red wire goes to the marked + terminal (it is stamped on the back of the motor, can be hard to see without good lighting)
3. Black wire goes to the other terminal
   
4. It can help to pre-tin (apply some solder to) the motor terminals first as shown here:
   
   
5. Then solder on the wires as shown:
   
   
6. You should now have a finished assembly that looks something like this (After doing both motors):
   
   

Assemble the Components into the Chassis:

1. First slide the two motor faceplates down into the slots on either side of the chassis. And place the kakapo down into the well at the back side of the chassis where the holes in the bottom are as shown:
   
   
2. Now flip the chassis over, you should be able to align the kakapo so the 2 screw holes closest to the back are aligned to the integrated nuts on the kakapo, as shown:
   
   
3. Now secure the Kakapo in place using the 2x M3x6mm screws from the kit as shown:
   
   
4. It should now look something like this from the top:
   
5. Now is a good time to ensure the JST connectors are accessible You will need them (at the least the Male) to plug in battery, and/or ESC. Also note the 3 pin header on the Kakapo below, that connector is a servo output for connecting a weapon (either servo, or an ESC).
6. Also ensure the twist switch on the kakapo is in the OFF position (partially unscrewed) by turning it about one full turn Anti-Clockwise:
   
   
7. Note, this twist switch is the main power switch for your bot, Clockwise until tight, is ON, and Anti-Clockwise until loose (about one full turn) is OFF

Some quick tests to ensure everything is ready to proceed:

1. Test the circuit
   1. using an ohm meter you should check that there is not a short between the +/- pins on the JST connector for the battery or weapon
   2. If an ohm meter is not available, simply inspect your solder joints to ensure no inadvertant connection is made between a +/i wire/pad.
2. Ensure the twist switch screw on the bottom of the Kakapo is partially unscrewed (the “OFF” position)
   1. Install the battery, by plugging it into the power circuit input, carefully observe for smoke or puffing of the battery for a few moments.
      
      
   2. If the battery appears ok, then proceed to turn on the power, by twisting the twist switch screw in all the way, this should engage the “ON” position.
   3. The LEDs on the Kakapo should now illuminate to indicate power is on.
   4. Turn the power back off, and remove the battery
3. Install the wedge module by sliding the dovetails into the slots in the front of the chassis.

Pair the Transmitter

This procedure is for the ELRS Transmitter and Receiver, if using an alternate transmitter/receiver type, you will need to follow appropriate directions for that receiver

1. Install the battery into the bot
2. Power on the Transmitter
3. Configure A Binding Phrase on your ELRS Transmitter (if you already have a binding phrase set on the transmitter which you remember you don't need to do this again):
   
   1. On the transmitter, long press the menu button to enter System menu, which should show you the Scripts list. Press Select on the ExpressLRS App, which will open the ExpressLRS Menu
   2. Scroll down to "Wifi Connectivity" and enter that menu
   3. Then scroll down to "Enable Wifi" and click/select on that option
   4. Once wifi is enabled, on your mobile phone or laptop, connect to the wifi access point named "ExpressLRS TX" And connect to it. It's password is "expresslrs" all lower case, no quotes.
   5. Once connected, open a web browser, and browse to https://10.0.0.1/ to access the ExpressLRS Web UI
   6. When the page has loaded, you will scroll to the Runtime Options section, and add your binding phrase:
      
      
   7. Enter a phrase that is at least 8 alphanumeric characters, and which is unique to you (and which you will remember).
   8. Ensure you save your settings (scroll to the bottom of the page), and then you can exit wifi mode on the transmitter, and power off, then back on the transmitter to ensure the binding phrase is being applied.
4. Now set the binding phrase on the Receiver
   1. Power on the bot, the LED on the ELRS receiver should be blinking slowly indicating it is unbound.
   2. Wait 1 minute. The LED should begin blinking constantly, and very rapidly to indicate it has entered wifi mode.
   3. Follow the same steps you did for the Transmitter, this time connecting to the wifi access point called "ExpressLRS RX", with the same password ("expresslrs"), and set the same binding phrase that you chose on your transmitter. 
   4. Save the settings, and once saved, power off the bot.
   5. Now when you power the bot back on, with the transmitter already powered on, the LED should blink slowly for a moment, then switch to a solid LED to indicate it has connected, and your Transmitter should show RSSI signal to indicate the receiver is connected.

For any further help with the ExpressLRS Web UI, please look at: https://www.expresslrs.org/quick-start/webui/

As it has details of exactly how the Web UI Works and all the other settings, etc.

Final Assembly & Close up the bot

Now you can safely tuck all the electronics into the electronics compartment, and make sure the lid securely bolts down with the battery installed. If need be, manipulate placement of the wires so everything works, and you can easily get the battery in and out.

If you have a weapon module, now you can install it, and wire it's ESC to the Weapon Power Output, and 3 pin signal pins on the Kakapo.

Install the wheels by pressing them onto the shaft (note the wheels have a hole with a flat to match the D shaft on the motors, make sure you line it up correctly. It can sometimes help to use a small amount of glue to secure the wheels onto the shafts if the press fit isn't tight enough.

When done the bot should look something like this: (note this photo has the old wedge, the newer TPU wedge looks different than this, otherwise the bot is the same):

Configure/Calibrate the Kakapo

To calibrate the kakapo, ensure the transmitter is turned on, and armed (left switch flipped up). And then power on the bot. 

It may be helpful to perform this procedure with the lid off the bot so you can see the LED indicators on the Kakapo board (though they are usually visible through the chassis as they are quite bright)

For completion of the calibration routine, please refer to the instructions for the Kakapo from CB-Tech at the following link:

https://github.com/cb-repo/P033-KAKAPO-2A?tab=readme-ov-file#calibraiton

(Note: this page also has other great technical info on how to use the kakapo)

These instructions may evolve over time, so that will always refer to the latest version of the instructions.

Balance the Bot

It is important that once you’ve fully assembled and calibrated the bot, and added any additions/modules/customizations, that the bot is balanced.

Since it runs on 2 wheels, you want the center of gravity to be slightly forward of the wheels. This will keep the front from lifting up (wheelie) when driving forward as you’ll want your front wedge to stay on the ground to prevent opponent bots from getting under you.

You also don’t want ALL your weight forward, as this will reduce your traction. Finding the “sweet spot” for balance will take a bit of trial and error.

The kit is designed so that there is a small compartment behind the wedge which is enclosed with the wedge installed. This area can take weights (coins, nuts, or other metal bits to add weight). So that you can balance the bot. It is suggested you secure it in place with tape, or some kind of glue (hot glue works). Then cover with the wedge once done, securing the wedge in place with the 2 10mm screws and matching nuts in the recesses behind.

Ideally your final weight is as close to 150g as possible, while still being under the limit (this will optimise your traction and pushing power).