Hello again and welcome back for our update on our Monster Book of Monsters Instructable! In our past Instructable we presented the steps of creating the exterior of our Monster Book of Monsters. While googly eyes and clay tentacles created a creepy critter, we wanted to elevate our monstrous design by giving our Monster Book of Monsters the gift of movement.
Using products from Digilent Inc.'s Box Monster kit and following the Box Monster Instructable as a guide, we updated some parts and put them all together to make a monstrous, moving, Monster Book of Monsters. So follow us as we embrace the books that many of us came to love with a project that channels the magic found inside us all.
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Step 1: Collect Materials
For those of you who followed our previous Instructable, you may have already completed your Monster Book of Monsters exterior design. If you did not have a chance to make your box yet, don't fret. There is always time to create your box after reading through our mechanical Instructable.
Eventually you will need a completed exterior box design, and the parts that accompany the Box Monster kit found here. These items include:
- a chipKIT uC32 microcontroller
- a USB A to mini B cable
- a GWS servo kit
- a battery holder that uses 4 AA batteries
- the 4 AA batteries for your battery holder
- some breadboard jumper wires (it might help to have red, white, and black colored wires)
- a 3D printer
- a small screwdriver
- craft wire and wire cutters
- a large zip tie
There are also some optional supplies you may want to find. These include:
- an x-acto knife
Once you have these supplies you can get started working on your updated monster box.
Step 2: 3D Print Revised Parts
We started this project by first printing new 3D parts that needed revision from the original Box Monster Instructable. The original project supplies a brass wire to connect the servo and servo horn, but we realized that this part would not be strong enough to support the heavily weighted Monster Book of Monsters lid with sustained use. To avoid the wire from collapsing we decided to print new parts with our 3D printer. You can find the gcode files for this step below, and we will update this Instructable with the STL files soon.
Step 3: Program the UC32
When programming our Monster Book of Monsters, we changed the code slightly from the original Box Monster Instructable. The original code can be found by clicking on the link to the original Instructable, or you can download our updated version attached below. We chose to delete part of the original code to help our Monster Book of Monsters appear more like the movie version, that opens the lid only slightly for a biting motion.
After downloading either the new or original codes provided, plug in your chipKIT uC32 using the cord provided in our materials list. If you do not previously have the MPIDE software installed on your computer, you will want to download that here. With your chipKIT uC32 plugged in, open your MPIDE software then click File->Open and choose the provided zip file. For more information on this step you can follow the links provided in the original Box Monster Instructable.
Once the file is opened in MPIDE, click the upload button in your program to complete the file upload to your chipKIT uC32.
Step 4: Connect the 3D Printed Parts
With all of your parts finished, you can now start to connect all of the smaller printed and provided mechanical pieces together. In this step we started with our servo by screwing on the arm piece provided with your GWS servo kit. Inside the kit you will find a few different parts that are interchangeable and can be screwed directly onto your servo with the provided screws. Pick the white piece that is shown in our photos and attach it to your servo so that it lies horizontal to the bottom of your servo. This should help your box work as intended.
Next, take your newly 3D printed push rod and attach it to your servo horn using the brass craft wire. Be careful when connecting these parts as they will need the ability to rotate around your brass wire. Our first picture shows how the pieces should be connected, with the 3D printed push rod placed around your servo horn. The hole closest to the edge on your servo horn should be lined up with the small holes on your push rod, and connected by craft wire to hold the two pieces together.
You can then attach the 3D printed servo horn in a similar fashion to the other end of your push rod (see picture 3). Although we used the second hole from our corner due to printing issues, the first hole is often better for rotating movements. When you have each piece connected by the wire, make sure you trim excess wire and bend towards the flat, planar surface of your push rod to eliminate obstacles when each part moves.
Step 5: Prepare the Servo
Before securing the servo with zip ties, you will need to organize your box and decide where the servo will be positioned. We placed our batteries in the back left, and the chipKIT uC32 in the back right of our box. This created more room for the servo to move when power was connected.
Since our box was very top heavy, we decided to position our servo closer to the front of our box. Placing your servo closer to the front will reduce torque and make the lifting job easier for your servo. When you have found a good place for your servo (i.e., close to the front and center of your box), draw a line to mark the place you will use an X-Acto knife to cut. Drawing a line will prevent larger cuts than necessary and help your box maintain a cleaner appearance. After drawing your line and marking your servo's correct position, cut the size to fit the plastic that extends from the bottom of your servo. Test your work by placing your servo through the newly cut hole, making sure it sits flat in your box.
Step 6: Plug in the Wires
Before attaching the servo with zip ties, you will want to test the movement by connecting all of the wires. We started by connecting one red and one black breadboard wire across from the red and black battery pack wires (see picture 1). The red wire was then connected to our chipKIT uC32 to the voltage input pin (VIN) and the black wire connected to the GND pin (see picture 2). With these connected, your chipKIT uC32 will turn on a red light to show that the board is receiving power. You may want to cut another hole in the bottom of your box now, similarly to how we did in Step 5: Prepare the Servo. Cutting a hole for your battery connection will enable you to turn your box on and off without damaging your project when the servo is fully connected and moving. After cutting another hole, you can push the breadboard wires connected to your battery pack through the hole.
The next step is connecting your servo to your chipKIT uC32. Like before you will connect the red, white, and black breadboard wires across from the same colors extending from your servo (see picture 3). The red and black breadboard wires will be connected to the power header on your chipKIT uC32. The black breadboard wire will be plugged in next to your other black wire in the second GND pin, while the red wire will be connected alongside the black wire in the 5 volt (5VO) pin (see picture 4). Finally you will plug in your last remaining white breadboard wire in the PWM/Digital header in pin 11 (see picture 5). This will start your servo motor working as it begins to push the push rod (and attached servo horn) up and down. If the servo is not pushing the push rod vertically up and down, you may need to readjust the white servo horn by unscrewing, adjusting, and screwing the horn on again once in the correct position.
Step 7: Make the Finishing Touches
When you have throughly tested the servo movements, you can attach it to the bottom of your box using a zip tie. Connecting the zip tie under your box will create a cleaner appearance but cause your box to sit unevenly on a flat surface. Instead we suggest that you tie your zip tie inside your box and cut off any excess tie that remains (see picture 1).
We then shoved our 3D printed servo horn under the popsicle stick contraption holding our clay jaws onto the top of our box. This allowed us to reopen our box, after everything was set in place, to correct anything that might needed adjusting. If you decide to attach your 3D printed servo horn to the lid of your box with glue or another adhesive substance, be careful to test everything as well as possible before applying the adhesive. Your box may tear with extended use.
Step 8: Watch Out! Your Monster Book of Monsters Is Alive!
With everything set in place, you are now ready to start your box and watch it magically come alive! With the added mechanics you now have a fully functional replica of the Monster Book of Monsters as seen in the Harry Potter movies.