CNC Platform
How to use a CNC machine to create the Scrapeboard platform.
Wood shell
Using a single piece of plywood and CNC machine, follow the phases below to carve out pockets to form the wood shell of the platform controller. Metal plates, rubber feet, hinges, wiring, and a microcontroller will be fastened to the wood to create the full controller.
CNC project
Download the ZIP archive (CRC32: 8966bf67) or get the individual files from the Git repository.
The CNC project consists of a sequence of vector files, each pertaining to a phase of the project. Each phase corresponds to one bit type and depth, so each can be performed as a single, uninterrupted run of the CNC machine. Follow the phases below in sequence to create the wood panels for the platform controller.
The ZIP archive Scrapeboard_Platform_Controller_CNC.zip contains the following files.
| File | Description |
|---|---|
README.md |
File that links to this wiki page |
CNC_Platform_v2_30x30.xcf |
GIMP project containing each run as a path |
Scrapeboard_CNC_preview.png |
Preview of what the GIMP project looks like |
01_BOTTOM_Wire_and_feet_pockets_0.1875in_depth.svg |
Vector of the 1st CNC run for wire channels and feet pockets |
02_BOTTOM_Microcontroller_pocket_0.3125in_depth.svg |
Vector of the 2nd CNC run for the microcontroller pocket |
03_BOTTOM_Connector_pockets_0.25in_depth.svg |
Vector of the 3rd CNC run for the screw connector pockets |
04_TOP_Plates_0.125in_depth.svg |
Vector of the 4th CNC run for the metal plate pockets |
05_TOP_Bore_holes_0.75in_depth.svg |
Vector of the 5th CNC run for boring screw holes |
06_TOP_Perimeter_outer_cut_0.75in_depth.svg |
Vector of the 6th CNC run for cutting out the platform |
GIMP
Open the file CNC_Platform_v2_30x30.xcf with GIMP to view the entire project on one canvas. Each phase is included in the project as a path. The image should be 30" x 30", which is 9000px x 9000px at 300dpi.
Supplies
30" x 30"or larger CNC machine with support for SVG files30" x 30" x 3/4"or larger high grade plywood. Sande plywood has worked well, and oak is also recommended.- Straight bits for CNC router. It's recommended to use a
1"bit for large pockets,1/4"bit for medium pockets, and a1/8"bit for small pockets.
Setup
The wood must be fastened to the CNC bed before starting. The CNC files measure 30x30", but the final platform is 28.5x28.5". The reason the files are larger is to give a buffer of 3/4" around the perimeter which can be used to fasten the wood to the bed.
Phases
Once the CNC machine has been started and calibrated for the 30x30" files, follow the phases below to create the wood panels for the platform controller.
Each phase corresponds to one bit and depth, so that each can be performed by a single, uninterrupted run of the CNC machine. The project is split into phases to be run on the bottom of the platform, followed by phases to be run on the top.
Bottom
Run the following phases on the underside of the platform, where the microchip, rubber feet, and wiring will be installed.
Phase 1
| Component | Value |
|---|---|
| File | 01_BOTTOM_Wire_and_feet_pockets_0.1875in_depth.svg |
| Side | Bottom |
| Bit type | Straight bit |
| Bit size | 1/4" or smaller |
| Depth | 3/16" (0.1875") |
On the bottom of the plywood, route channels for wires and carve pockets for rubber feet.
The wire channels are much thinner than the feet pockets, so an optimization could be made by splitting this into two phases with a small bit for wire channels and large bit for feet pockets.
Phase 2
| Component | Value |
|---|---|
| File | 02_BOTTOM_Microcontroller_pocket_0.3125in_depth.svg |
| Side | Bottom |
| Bit type | Straight bit |
| Bit size | 1" or smaller |
| Depth | 5/16" (0.3125") |
Carve a deep pocket which will house the microcontroller.
Phase 3
| Component | Value |
|---|---|
| File | 03_BOTTOM_Connector_pockets_0.25in_depth.svg |
| Side | Bottom |
| Bit type | Straight bit |
| Bit size | 1/4" or smaller |
| Depth | 1/4" (0.25") |
Carve pockets for nuts which will be fastened to machine screws, one for each metal plate. These pockets are used to connect the metal plates on top of the platform to the wires on the underside.
Top
Flip the platform over the Y-axis, making sure the platform is fastened to the bed in the same position as it was for the bottom phases. Run the following phases on the top side, where the metal plates will be attached.
Phase 4
| Component | Value |
|---|---|
| File | 04_TOP_Plates_0.125in_depth.svg |
| Side | Top |
| Bit type | Straight bit |
| Bit size | 1" recommended |
| Depth | 1/8" (0.125") |
Route pockets where the metal plates will be inset into the wood. It's important to make sure the depth is precise in this step because the metal should be as flush with the wood as possible.
Phase 5
| Component | Value |
|---|---|
| File | 05_TOP_Bore_holes_0.75in_depth.svg |
| Side | Top |
| Bit type | Straight bit |
| Bit size | 1/8" or smaller |
| Depth | 3/4" (0.75") |
Use the straight bit to bore holes all the way through the wood. These holes will be used for insetting threaded inserts which will be used to fasten the metal to the platform. One smaller hole per plate will be used for a machine screw which will connect the plate to wires on the underside.
If the plywood does not have any wood underneath itself on the bed, the depth must be adjusted so that the router does not cut into the bed. The holes do not necessarily have to go all the way through the wood, just close to the edge.
Phase 6
| Component | Value |
|---|---|
| File | 06_TOP_Perimeter_outer_cut_0.75in_depth.svg |
| Side | Top |
| Bit type | Straight bit |
| Bit size | any |
| Depth | 3/4" (0.75") |
This cut carves the platform itself out from the buffer of plywood around the edge. Set the CNC machine to do an outer cut, and cut along the path in this file.
If the plywood does not have any wood underneath itself on the bed, the depth must be adjusted so that the router does not cut into the bed. If necessary, perform this cut once on the top side, and then repeat on the underside.
Mounting
The metal plates, microcontroller, wires, rubber feet, and hinges can now be fastened to the wood panels.
Metal plates
The details on how to fasten the metal plates are available in Improved Platform. However, there are a few important updates.
The project is now designed to use slightly smaller #10-24 x 5/8" machine screws. The screws are fastened using threaded inserts rather than nuts. The threaded inserts should be inserted into the holes under the metal before placing the metal plates.
For each plate, there is one screw hole which is slightly smaller than the rest that has a pocket on the underside of the platform. That smaller hole is intended for the original #12-24 x 5/8" machine screw and corresponding nut. This screw is used to connect the metal plate to the wires.
Also, the platform has been updated to use 1/8" thick aluminum sheet metal. Therefore, instead of countersinking the wood under the metal and pulling the metal inward, countersink the metal itself, which is now thick enough to be countersunk for the machine screws.
Microcontroller
This version of the platform controller is designed to be used with a built-in micro Arduino fastened to the underside of the plywood. The circuit is same as described in Electronics. In this version, all the components are mounted to a protoboard, which is mounted to the plywood in the channel created in bottom phase 4 and wired to the metal plates.
This is an image of an earlier prototype. In the final build, the channel is larger, and the microcontroller board is rotated 90 degrees to the right and mounted to the left side of the channel.
The USB-C port of the microcontroller is what connects to the computer running Scrapeboard. Insert a USB-C cable (to USB-A, unless the computer uses a different port) to the port and run it through the channel going out the front of the platform. The cable should be looped and clasped to the wood with small screws, otherwise it may pull out of the port during gameplay.
Hinges
This step is optional. The platform is designed so it can fold in half, and it can be cut down the middle, for example using a table saw or jigsaw.
If cutting the platform in half, small hinges should be fastened along the X-axis on the underside of the platform, so the front half of the platform will fold onto the back half of the platform.
Wires
Use the channels created in phase 1 to run four wires to the screw terminals contained on the microcontroller, one wire for each metal plate.
It is recommended to use 20 gauge wire, rather than the 16 gauge wire previously used. The wires are now much shorter because they don't need to reach outside the platform. There are instructions on how to strip the wires and attach them to the metal plates in Improved Platform.
Rubber feet
Rubber feet should be fastened in the channels created in phase 1, one foot in each channel, making 16 feet total.
If the platform is being folded along the X-axis, the feet should be staggered so that when folded, each foot will fold in next to its corresponding foot on the opposite side of the X-axis. For example, if fastening a foot in the top half of the top left channel, the foot in the bottom left channel should also be fastened to the top of the channel. This way, the feet won't collide when the platform is folded.
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