Multi-Purpose Plywood Robot Prototyping Base

Why to spend your bucks on ready-made metal or acrylic robot bases when you can make one yourself! Yeah, so this instructable is gonna teach you how to make a plywood robot prototyping base platform. You surely need them when you are a beginner and want to get started with robotics or even when you are planning to prototype a bigger robot project first on a small scale. There is no way to make a cardboard base which will surely fall apart within a couple of projects or to buy acrylic bases which would be beyond your budget. So here is a cheap ye effective solution- Plywood. This can easily be worked upon, durable and will easily fit in your budget without any doubt. You just have to give some time for a little bit of drilling, sanding and cutting.

The instructable covers the entire process of preparing your plywood base, adding motors and wheels and even to make a DIY motor driver. At last, there is a basic project to check whether if everything is done correctly. In all, you will require a maximum of 3 hours to do the entire process. So this can also be a beginner project for taking the first step to getting started with robotics. After completing this project, you can then try some of the very basic robots such as these:

1. Simple Remote Controlled Robot (Wired) (Easy)
2. Wireless Remote Controlled Robot (Wireless) (Easy)
3. Line Follower Robot (Black or White line) (Medium)
4. Light Seeking Robot (Medium)
5. Obstacle Avoiding Robot (Medium)
6. Edge Avoiding Robot (a.k.a. Table Top Robot) (Medium)
7. Wall Following Robot (keeps following the corners) (Medium)
8. Gesture Controlled Robot (Hard)
9. Bluetooth Controlled Robot (Hard)
10. WiFi Controlled Robot (Hard)

(The first two projects do not require any microcontrollers while the last ones do. Rest all may or may not need it)

Update: Added a video of the robot in action (with a simple arduino project):

I will really appreciate if you vote for me in the Spectrum Laser & Plywood Contest. The prizes (especially the laser cutter) will help me greatly for my further projects. Actually, not having a laser cutter is the reason which prevents me from using acrylic or wood for most of my projects. Hope they can award me one :)

If you have any doubts related to this instructable, please mention it in the comment section below or you can drop me a mail at the address provided in my bio. If you are passionate enough to attempt the project, do post the pictures below. Please have a look at my new tech blog- SirKit Studio for more cool projects and updates. You can subscribe to my YouTube Channel as well....

Project Made in India, with Love! ;)

Step 1: Watch the Video

If you are too lazy to read all the instructions given in this instructable, you can watch this video with complete step by step instructions:

Please subscribe to my YouTube channel as well :)

You can even watch this video on making a solar phone charger in 10 minutes!

Step 2: Parts and Tools

Below is the list of parts, tools and materials for making this project. Please note that the list doesn't consist of parts that will actually be required to get your robot running eg.- microcontrollers or transceivers. These are the basic parts for making the base and adding motors + driver only.

Parts/Materials:

• Plywood plank (atleast 8" x 7" x 1/4")
• 2x Geared motors (recommended- 300rpm, although any one between 100-1000rpm should work)
• 2x Wheels compatible with your motors
• 2x Motor mounting metal clamps (you can even make them yourself)
• 1x Caster wheel (this can be salvaged from old toys)
• 2x Metal posts for mounting your caster
• 1x AA battery holder (with 4 compartments)
• 4x AA batteries
• 1/12" Nuts and screws as per your requirements

Optional (for motor driver):

• 1x L293d motor driver IC
• 1x 8 pin IC socket
• 1x Screw terminal
• Male headers
• Wire
• Perforated board

Tools:

• Soldering iron + wire
• Multi purpose rotatory tool (with Drill bit, Sanding drum, Cutting wheel, Grinder)
• Hack saw
• Screw driver
• Pliers
• Wire cutter
• Some double sided tape

Total cost of parts: $25 (1600 INR approx.)

Step 3: Mark and Cut the Base

Here we start by first cutting the plywood base to an appropriate size. If you already have a normal size board, you can straight away skip this step. Now when thinking about the right size, first decide whether you want the base to be rectangular or square shaped. For square shape, it should be quite easy as the ratio of length and breadth will be 1:1. However for the robot to look better, you should always go towards a rectangular base.

Ideally, the length should be 8" and breadth 6" which can vary as per your design plans and requirements. Make sure to keep the ratio of length to breadth approx 4:3. First mark, using a pencil the correct measurements and then cut the wood using a hack saw. While cutting, always ensure that you're moving the saw straight.

Step 4: Sand the Edges

After cutting wood, it is always important to sand the corners to eliminate any sharp edges that may hurt you. Using a sand paper or a rotatory tool, cleanly sand the entire side portion and corners. This also helps to make non-uniform cuts smooth.

Step 5: Mark and Drill Holes for the Caster

After you've prepared the wooden base, you'll now have to start mounting all the peripherals, one of them being the caster wheel. Although you may already have guessed the purpose of it by simply looking at the shape, it acts as a support for the front part to move freely with less friction thus eliminating the need to add four motors to the robot.

Here you just have to mark two holes for the wheel at the correct position and drill them using a 1.5 mm drill bit. Please be accurate with the markings as you will not be able to add the screw in place.

Step 6: Fix the Wheel in Place

Now after drilling the holes, check if you've done it all correct and then using some screws, fix the wheel in place. For balancing the robot you may also need to add metal posts as I have done so that the feel is mounted at a height.

The wheel you bought would possibly not be the same as mentioned above so you've to do it all on your own. Please don't stick to the picture.

Step 7: Solder Wires and Add Clamps to Your Motors

For easily connecting your motors to drivers/shields, it is always a good idea to solder the wires before mounting them. So what you have to do is to take two female to female jumper wires and cut both of them into half. Then solder both the halves to both of the motors. Secure the connections by adding some hot glue to the joints.

Next, attach the clamps to both of your motors with some long screw and nuts. If you didn't get a clamp, you can even make one using aluminium or wood. If not, then you can simply glue it later.

Step 8: Mark Holes for Mounting the Motor

Also this may seem easy, you have to be very accurate here else you will have your robot not moving perfectly straight. With your clamps mounted, place your motors exactly at the place you want it to be. It is better to take the wheel and check if it remains within the base. I also decided to place the motor a little more towards the centre so that the wheel is directed inwards which makes it look better.

Along with mounting atleast two holes for each motor, mount a rectangular part to be cut out for the wheel to be mounted a bit inwards. The part to be cut should have length a 0.5 cm more than the diameter's wheel while the breadth should be half of the thickness of your wheel. Mark everything darkly with a pencil and twice check everything.

Step 9: Drill Again

Drill the respective holes for each of the motors with the same drill bit that you used before. After drilling, check if you have done it all correctly and the screws can pass through easily.

Step 10: Cut Excess Wood for Wheels to Move Freely

Now comes the messy part. You have to now cut out the rectangular pieces of wood for the wheels to fit in the motor and move freely. Start by cutting along the breadth using a hacksaw. Now the remaining length can't be cut using that so you will probably need a cutting plate to do this.

Set the speed to maximum and with a tight grip and good control, you will be able to easily do it. Be very accurate as it may look a bit ugly of not done correctly. Please wear a dust mask and proper safety equipment while doing this if you didn't use it previously as there might be a high risk of the disc breaking off. After successfully cutting it off, sand all the edges properly to avoid any injuries. Lastly, check if a wheel can easily accommodate in and doesn't touch the edges.

Step 11: Mount the Motors

Using two screws and nuts for each motor, mount them at their respective places and tighten the screws with a screwdriver. At the end, check if it's all good.

Step 12: Add the Wheels

You won't need a detailed description for this one. Just place the wheels on the motors and you'll now see your robot standing perfectly. If there are any height problems, be sure to rectify them here itself.

Step 13: Giving a Better Design (Optional)

One more thing you can do with your robot base is to smoothen the two front corners and give them a circular shape. This will not make anything better but only the looks thus not mandatory. I decided to do it just because the shape was looking a little weird.

All you have to do is, first mark the shape with a pencil and then shape the corners with a grinder. After you're done, make the shape a little smoother by sanding it.

Step 14: Yet More Drilling

Now you'll have to drill two more holes for the motor wires to pass through to be connected to the driver circuit later. The holes have to be a little bigger for the female headers to pass through. You can even make a single hole for all the four wires to pass through.

Step 15: Solder the Motor Driver Circuit (Optional)

If you believe on doing everything yourself, then you may also consider making the motor driver circuit on your own instead of buying a ready made one. Don't worry, it's not a very complicated thing to make. You just need some basic soldering skills and this single step itself will teach you how to.

Start by cutting small rectangular piece of perforated or protoboard. Solder all the parts as mentioned in the schematic above. Be sure to use an IC socket for the driver chip to reduce the risk of burning it. If you want to make the process more simple, you can even etch your own PCB instead of using wires for connections.

Apart from the IC, you need to solder 2 pair of male headers, each for a motor. 2 more pairs for the input signal for each motor. A pair for +5v and Gnd supply to the IC and lastly, a screw connector for powering the motors. The two additional headers beside the screw terminal are simply connected to it to get an output supply from the battery connected. Please note that the battery connected will only be used to power the two motors. The driver IC will get a separate 5v for it's inner workings.

Step 16: Mount the Circuit on the Base

After soldering the circuit, now you have to mount it on the robot base. For this, you can use either 1 or 2 screws and it would be just fine. For this, you will have to drill a hole both on the PCB as well as the base. Then just use a screw and nut to mount it.

If you're too lazy, you can even use double sided tape or hot glue to temporarily attach it.

Step 17: Connect the Motors to the Circuit

This step will be very easy if you already have female headers attached to each one of the motor wires. Otherwise, you will have to solder them to the circuit. So all you have to do now is connect the wires as per the following:

• Right motor (as seen from the back) +ve (white) ---------- Pin 3 of motor driver IC
• Right motor -ve (black) ----------- Pin 6 of IC
• Left motor +ve (white) ---------- Pin 14 of IC
• Left motor -ve (black) ---------- Pin 11 of IC

Step 18: Mount and Connect Your Battery Pack

This is basically the last step to complete the building process of your DIY robot base. The next two steps are just for checking if the project is ready to move and has all the corrections correct. Here, you have to mount your battery pack that will be used to power the two motors.

Before that, you may face some difficulty in selecting the battery pack. I used the simplest option- 4 Ni-Mh rechargeable batteries to produce approx 5-6v which is more that enough. You may also use Li-ion or lead acid battery packs as I did in my previous instructables.

First you have to drill a hole if you're using a zip tie like I did. Using the tie, keep the pack in place and make it tight enough to not fall off. You may also need to remove it sometime so don't make it overtight.

Step 19: First Try: Make the Connections

So now you're finally done with making the base and adding the necessary parts. This step is to optional and is to basically check that of everything is ok. I will be using an arduino as the brain to make the robot first move forward and then right, left, backwards. For this, first you have to make all the connections from the arduino board to the motor driver. You can use UNO, Nano or any compatible version. Use jumper wires to make the connections as this will only be a temporary project.

• Arduino Vcc -------- Battery +ve terminal
• Arduino 5v --------- Pin 1, 9, 16 of motor driver IC
• Arduino Gnd -------- Pin 4, 5, 12, 13 of IC & Battery -ve terminal
• Arduino Digital pin 5 ------- Pin 2 of IC
• Arduino Digital pin 6 ------- Pin 7 of IC
• Arduino Digital pin 9 ------- Pin 10 of IC
• Arduino Digital pin 10 ----- Pin 15 of IC

After making all the connections, mount your arduino temporarily to front vacant part of the base using some double sided tape. Before that, you should make sure that there are no screws or metal parts exposed. If yes, then insulate all of them with some tape before mounting your board. In case you are using arduino Nano, you may need a shield or anything similar for making the connections with jumper wires as in my case.

Step 20: Upload the Code and Check

After you're done with making all the connections, the next thing you will have to do is to upload the code provided below. First select the correct board and serial port on your IDE and then download and upload the code present in the ino file below.

Finally, connect the battery snap to your mounted pack and you should see the LEDs on your arduino light up. Now immediately leave the robot on a smooth floor and you would see the robot hovering as per the following:

• Forward for 3 sec. at decreasing speed
• Right for 2 sec.
• Left for 2 sec.
• Backward for 3 sec. at decreasing speed

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Troubleshooting:

Q1: Robot moving left or right when it should move forward?

A1: Try swapping the connections of the left or right motors to motor driver. After a bit of experimenting, you should finally get it right.

Q2: Robot moving backwards when it should move forward?

A2: Swap the connections of both the motors.

Q3: Robot not moving at all but LEDs on arduino are glowing?

A3: Check all the connections again or check if your driver circuit is soldered correctly.

Q4: Nothing working, even the arduino?

A4: Check if your batteries are connected properly or if they are fully charged.

Step 21: The End

The fact that this instructable ends doesn't mean that your creativity does! So this is just the beginning for you. Now you can try some basic projects given in the introduction part. Be sure that you make good use of this thing. There are a lot of other ideas that can pop up in your mind.

This was probably the last instructable before my board exams end. However, you can drop a comment below if you have any question.

Don't forget to have a look at my new blog: SirKit Studio

That's it for this instructable, thanks for watching :)