Introduction: Fully Functional 3D Printed BattleBot Using Tinkercad
Have you ever watched an episode of BattleBots and wanted to build one for yourself? Well, I have and that is what got me into building them! The video above is a my real life battlebot that fights in tournaments across the USA! The best part is, you could make one too!
Create an Antweight (1lb) combat robot, and let them take the foundation of proper design integrity and knowledge in this instructable, to use it for designing their own combat robot for a fun project. Just because you might not have a 3D printer at your disposal, or COVID-19 prevents them from using a Makerspace owned one, many low cost 3D printer service options are available if you love your design so much - you can build it!
All the informative resources that are needed to design a combat robot are included in this instructable, and electronics can be used from an R/C car, or found in my other instructable which goes through the electronics in more detail and has links for places to buy at an affordable cost.
By following through this instructable, you will have the power and design knowledge to build one and design it in Tinkercad, an online CAD (Computer Aided Drafting) program. Use this as a reference, guide, or exact outline for building and designing with distance from the physical classroom.
To follow along step-by-step, go to www.tinkercad.com and design your own custom robot based on this instructable.
This robot will be under 1lb, allowing for it to be entered in competitions across the USA, and a lot easier to transport!
Step 1: The Weapon of Choice
First off, choose between the three main weapon types! There is a short description of each below:
Horizontal Spinner - Uses a bar or disc that spins parallel to the ground, allowing for the blade to dish out and slice opponents from the side.
Vertical Spinner - Just like a horizontal spinner, a bar or disc spins at a high speed and uses the tips of the blade to deliver a blow to the opponent. But, (as you may have guessed) the blade spins perpendicular to the ground, allowing for the blade to hit the underside of the opponent, which is usually the least protected.
Drum Spinner - Capable of dealing out large amounts of kinetic energy, a drum spinner is basically a cylinder spinning at a extremely high RPM and the cylinders has small teeth (180 degrees across the cylinder) which “bite” the opponents armor and potentially even obliterating the opponents wheels. The drum spinner also spins vertically.
The robot in the instructable will be using a drum spinner, but if desiring a different weapon, feel free to experiment with the robots design.
Step 2: Sizing and Building the Base
After selecting the motors of choice, design the bottom of the robot. A appropriate thickness is 1/16” thick, but 1/8” will also be stronger, but heavier. Ensure that the size of the bottom can fit the motors, as well as the rest of the electronics.
Step 3: Creating Walls for the Foundation Structure
Create walls and armor panels for the robot by using the rectangle shape, the sizing them to the length of the of the bottom. Select a wall thickness of at least 1/8”, but 1/4” will ensure that if a large impact is taken, the frame will stand up to it better.
Put walls for all sides of the robot (using the same thickness) and group/merge the shapes together by selecting all the shapes, the hitting “Control/command G”.
This singe structure will hold the biggest part of the robot successfully together.
Step 4: Create the Housing for the Weapon
Since this robot is going to have a drum spinner attached on it, do not forget to have the two walls (in the front), extend out so that the drum spinner can be mounted.
How exactly is a drum spinner mounted??
A drum spinner can be created and mounted in a variety of different ways, but in this robot, the motor will be inside of the drum spinner, and the drum will have a bearing extended out on the opposite side that can also fit into the frame.
Step 5: Creating Holes in the Design
Why would you want holes in your design?
Holes are beneficial because this will be a functional Battlebot and because of this, the motors, electronics, and lids need to be mounted using screws. In Tinkercad, the "snapping" on the grid can be adjusted to 1/8", 1/16", 1/32", etc. So, use digital calipers to measure the exact distance between holes (and the hole size themselves).
Once the measurements are all properly recorded, the convert them to a fraction, and use the arrow key to move the holes away from each other the proper amount, or use another shape to show the distance.
As shown in the photo: the rectangle the representing the length that the holes need to be apart, and the holes can be spaced by lining up to the rectangle, or using the "align" feature.
Step 6: Group and Merge the Holes
Just as shapes can be grouped together using the "group" feature, merge shapes and insert holes by selecting the desired objects and holes, the clicking the group button.
Expert Tip: If you ever need a specific part of an object copied to another design, but don't want to mess up the entire design, select the entire object, click ungroup until the desired object is available, then copy. After that, click the undo button until the object is back to normal. Paste in the other file when needed.
Step 7: Create a Custom Motor Mount
This robot uses a micro metal gear motor. But, the mount for this motor can reach up to $5 each! Save money and create one for yourself inside of the robot. Use the digital calipers again and measure the dimensions of the motor, then create a hole in Tinkercad the same side, then take out 1/16" from each side. Once the 3D printer completes the frame (while the print is still hot and moldable), push the motor into the hole meant for the motor and the plastic should slightly mold to the motor, ensuring a secure press fit.
Step 8: Subject Switch - Electronics
Before the next few parts in the design, it will be very beneficial to understand how the electronics work. Since this part is a little tricky, try checking out some of my other instructables, or put a question in the comments.
Drive motors to Drive Controller connection
Gather one drive motor, one drive controller, and 2 wire connector blocks with 2 spaces. On a wire connector block, lift up the lever, and slide a red wire from the drive motor in one space, and either a purple or blue wire from the drive controller. Repeat with the other wire connector block and 2nd wire of the drive motor and drive controller. Now repeat the same process with the second drive motor and drive controller. Drive Controller to Main Wire Connector Blocks and Receiver Take two, 5 space wire connector block, the receiver, and a drive controller. Lift all levers of both wire connector blocks and put a red wire from the drive controller in one connector block, and the black wire into the other wire connector block. Repeat with the second drive controller. Take the last wires of the drive controllers (with the black square on the end) and plug into the receiver in channels 1 and 2.
Weapon Motor to Weapon Controller connection
Take the red weapon motor, the brushless ESC, and 3, two space wire connector blocks. Plug each of the three black wires from the weapon motors into a separate wire connector block. Do the same with the brushless ESC. Now, take the red wire from the brushless esc and plug it into the 5 space wire connector block that has a RED wire plugged into it already. Now take the black wire and plug it into the wire connector block with the BLACK wire already plugged into in. Take the black and white wires and plug into channel 3 of the receiver. Plugging Battery into Power Switch Take the battery and plug the red JST connector and plug into the red JST connector from the power switch (male and female JST connection). Now take the black wire and plug into the black terminal block, and red into red terminal block.
Congratulations! The hard part is done!!
Step 9: Make the Drum Spinner
For these next steps, measure THREE times, cut once!
In Tinkercad, create a cylinder, then create a second cylinder as a hole. As shown in the picture, measure the bearing that is going to be used in the drum, then make the cylinder that is a hole, the exact same size.
Align the two cylinders (the hole and the solid one) and group the two. Then, add another smaller cylinder about 1/4" that is parallel to the ground. This will allow for a set screw to hold the bearing in place. Align and group when finished.
Step 10: Motor "Press Fit" Casing
Just like the mount for the bearing, follow the same steps and create a housing for the brushless out runner.
For the outside size of the motor and bearing housing, the size depends on the material that will be the "shell" of the drum. For this robot, a piece of strong tubing was cut-to-size and used, and the inside of the tubing was 1.43" , so that is what the Tinkercad-made housing is sized to on the outside. In this case, if unsure exactly, it is better to make it slightly bigger than needed because if too small, the motor will slip, but if slightly big, you may be able to press it in with a drill press or hammer.
Step 11: Print and Make the Drum Spinner
After printing all the parts for the drum spinner, put them into the tubing/material for the shell.
For a drum spinner to "catch" another robot and do damage, it needs teeth. In this case, rivet inserts that are threaded will allow for the screws, which will be the teeth for the drum. A rivet insert tool is needed to complete this step, but if one is not available, use the screw and two bolts to put it in. With no rivet tool, safety double lock the screws in with the following arrangement:
• Drill hole into the drum shell
• Put a nut on the screw
• Insert the screw (with a nut on it) into the hole
• Take the second nut and screw it on the inside of the drum shell
Step 12: Finished Drum Spinner
At this point, the drum is ready for a little dazzle effect. Spraypaint will stick to tubing nicely and showcase the hand built drum!
Step 13: Add Lid Holes
As shown in the photo, add small 1/8" holes for the lid. Small M3 screws will self tap themselves the plastic and in Tinkercad, duplicate the hole pattern and the "floor" of the combat robot, group the two, and print it separate to have a lid.
Step 14: Happy Building
From here, the sky is the limit! (Literally, try to use this drum spinner robot and hit a scrap piece of wood, I have reached a record of using the robot to send a can 15 feet in the air with a similar robot).
If you liked this instrucatable, feel free to ask any question or post in the comments, check out Tinkercad for yourself (easy and free CAD software), and Vote for this in the Robots Contest!
Happy Building Everyone!
Judges Prize in the