This is the assembly instructions for the Tiny Tank from Rocket Brand Studios. This is a great little robot kit, and can be purchased as a complete kit or as a rolling chassis, ready for the micro controller of your choice --Arudino Uno, Duemilanove and Nano, Picaxe 28 board, or Gadget Gangster Propeller Board. The Tiny Tank comes in lots of super-duper colors (and colours!) so be sure to stop by the website to see what is available.
Step 1: Prepare
You will need:
Soldering iron and small solder
Now, lets go ahead and talk about the elephant in the room... The laser-cut acrylic has a distinctive smell. The good news is that most of that funky goodness is in the paper backing of the plexi and not the actual plexiglass. Unwrap all the pieces by peeling off the paper plastic and get it out of the house. The smell will go with it, I promise.
Step 2: Assembly 1
- Start by soldering a capacitor and one red/black wire to your motor (see photo)
- Attaching the 2 motor mounts to the motors themselves with (2) 2-56 x 1" screws and nuts.
- Place the motor's cross member between the 2 motor mounts and place this assembly on the bottom plate
- Secure this assembly with (2) 2-56 x 3/8" screws and nuts
Step 3: Assembly 2
- Attach the 2 rear wheel supports to the rear cross member (note: this is similar to the motors)
- Place this assembly on the bottom plate
- Attach this assembly to the bottom plate with (2) 2-56 x 3/8 screws through the bottom plate
Step 4: Assembly 3
- Find the top deck and note the fact that there is one hole off-center (I am pointing to it in the picture). This hole is for the battery wires and must be on the left side when looking at the top of the deck
- Install the servo using (2) 2-56 x 3/8 screws
- Install the (4) 20mm stand-offs
- Route the servo wire through the front cross-member, then through the center hole of the top deck
- Route the motor wires through the center hole of the top deck
- Secure the top deck to the bottom assembly --Note the little needle nose pliers to help you sneak the nuts into where they need to go
Step 5: Assembly 4
- Prepare the battery pack. Find the (2) 2-pin leads and connect the 2 black wires to the black wire coming out of the battery pack --solder it and tape or shrink tube it. The red wire from the battery pack and the (2) red wires from the leads will be left disconnected for now, until we install the battery holder.
- Feed the battery wires through the battery wire hole in the top deck.
- Secure the battery pack to the top deck with (2) 2-56 x 1/4 flat head screws (they are the black ones)
- Install the 2 switches on the switch plate. You can place them so they switch vertically or horizontally
- Solder a small jumper between the two switches (see picture)
- Place the switch plate on to the top deck
- Solder the rest of the battery wires to the switches. The red wire from the battery pack gets added to the short jumper connecting the switches. This will send power from the battery to both switches.
- Of the two 2-conductor wires, one red wire of each will go to each switch (see picture)
Step 6: Assembly 5
- We need to decide what kinda brain we plan on using. If you did not purchase the full kit and/or are not using the Nano and Nano UnderShield, you need to use the rectangular plate. Place your microcontroller board onto this plate and determine which holes you will need to use to mount your board. Install any stand-offs or spacers you will need.
- If you purchased the full kit and/or are using the Nano and Nano UnderShield, use the funny-shaped plate. Install the (3) 10mm spacers.
- Pull the servo wire and the motor wires through the plate
- Mount the plate you have chosen to the robot on top of the (4) 20mm stand-offs
Step 7: Assembly 6
- Locate the (4) small circles and note that there are (2) biggies and (2) littles
- Place the axle bolt through the center hole of the rear wheels (the rear wheels have round holes --no "flat") --Also note that the "teeth" on the wheel point outward
- Place the metal washer on the axle bolt
- Place a small circle on the axle bolt
- Place a big circle on the axle bolt
- Attach this assembly to the robot and secure with the nut
- Repeat on the other side
- Press the front wheels on. Be very careful here, support the motor when pressing the motors on. Slide them on until they are "in line" with the rear wheels
- Stretch the tracks on.
Step 8: Assembly 7
- Assemble the sensor bracket by simply attaching the upright piece to the base piece with (2) 2-56 x 3/8 screws
- Hold the servo horn up to the sensor bracket and note what holes (in the horn) will be used for mounting
- Enlarge these holes with a small drill bit or (more easily) by spinning the tip of an Exacto Knife within the hole.
- Attach the servo horn to the sensor bracket
- If you bought the complete kit and/or are using a Sharp sensor, we need to prepare the pigtail wire. Find this 3-conductor wire and the small "servo-style" plastic end. Slide the wires of the pigtail into this connector (they will "click" when they go in the right way --If they are placed incorrectly, they will simply pull right back out when tugged) --The order of these wires MUST go White --> Red --> Black
- Plug the small white JST connector into the sharp sensor
- Attach the sensor to the bracket using (2) 4-40 screws, spacers and nuts
Step 9: Assembly 8
- Double check that you know which (2) red/black wires are from the switches and which (2) are from the motors. Loosely route these wires so they sorta point to where they will eventually connect.
- Pull the servo's wire forward and/or to where it will connect to your particular board
- Mount your microcontroller board making sure you don't pinch any wires between the brass stand-offs and the board
- Connect the 2 pwr wires. Ground is on the bottom. If you are using (4) alkaline batteries, use the connection on the end of the board. If you are using rechargables, use the connections at the edge of the board. (See the instruction manual for more info)
- Connect the 2 motor wires. It does not matter which way they go, you can determine the motors' direction during coding.
- Connect the servo wire --Note, ground is closest to the edge of the board and the signal wire it closest to the chip
- You may plug in your sharp sensor to one of the ADC inputs if you would like or you can wait and do this after the servo has been centered and the sensor bracket is attached.
- I personally like to run a "big-ol" cap (capacitor) on my power lines. I have found that microcontrollers are much happier with this little "boost" of power when it need it (when motors kick in, etc) --If you see any "funny" behavior from your little bot, you may want to add this cap as shown in the pictures.
Step 10: Assembly 9
At this point, you got yourself a robot. Now, all you gotta do is add some code. I am currently putting the finishing touches on some Tank-specific tutorials but the beauty of the arduino (or whatever motor controller you use) is the fact that the magical internets contain many, many tutorials. As a run-down, and highlights, here are a few things to have on your radar:
- There is some example code included with this step
- Run test code for each "sub-system" one at a time. Test the sharp sensor, servo, motors, etc before trying to "put them all together"
- Center your servo (through code) before mounting the sensor bracket.
- If the motors are not moving the correct direction, simply unplug one or both, flip the connector and plug it back in. This is much faster and easier than changing a lot of code.
- There are some more tutorials available here. Although for a different robot, they cover a lot of basic stuff, will translate well to what you are doing and include video walk-thoroughs of the code.
- Don't forget the Arduino Page
- Don't hesitate to shoot me an email --Can be found through the "contact" link at Rocket Brand Studios