Since the start of the lockdown, I have started a build project to keep my sanity 🙂 . I am building a digital pinball machine. To make the experience as close to the real deal as possible, the machine will have the shape and size of a real machine.
There have been several different shapes and sizes over the decades, but the one I know from my youth are the Williams solid state machines. Since my old cabinet was based on a wide body machine from that era, the new one will be a wide body also. Keep in mind that the term ‘wide body’ refers to the playfield part and is not a standard. Different manufacturers had different sizes for their machines.
The cabinet of my first machine was made out of MDF, particle board. Nice and soft, so easy to work with. But this time I have decided to go with plywood for two reasons:
- Dust. The particle board is soft and all but it creates lots and lots of very fine dust. I don’t want in my lungs while making it, especially when using a router. Also, the soft material means it dents easily once the machine is manhandled when played.
- Weight. MDF is very heavy. About 750 kg/m3, whereas plywood is about 500 kg/m3, so a third lighter. Different plywood have different weight of course, but it is always lighter then MDF. Not only makes it easier to handle while building. But it also means it is more realistic to nudge and tilt the machine when playing, since pinball machines are also made of plywood.
This machine will be made of 18mm plywood with 12mm in a few places since I have that lying around.
Now, before we go any further, these posts are not going to provide a step-by-step guide to build your own machine. But Michael Roberts, maker of the Pinscape controller board, provides a very detailed build guide on his website. It contains all the info you need to make your own machine and I have used it as a reference several times during the build of this machine.
Next up was making a cutlist. It is a sketch or plan on how to cut down a sheet to smaller pieces that you can then use to build the cabinet. A standard size sheet is 244cm x 122cm, or 8′ x 4′ for the Imperialists 😉 Even though a pinball machine is not made of only rectangles, the cut list does only specify rectangles so you end up making only rip cuts (length wise) and cross cuts (width wise).
If you want to make your own cut list, have a look at cutlistoptimizer.com. It is an online tool that helps to calculate your cut sheet based on the sizes of rectangles you need. You enter the stock you have, the pieces you need and width of the blade or margin you want to keep, and the tool calculates the best way for you to cut your sheets down with either fewest cuts or least waste.
I ended up with these cut lists to break town two sheets of plywood:
When building your machine, I suggest you spend a good amount of time thinking about your own cut list. Here is why:
- It helps to visualise the cabinet and its parts. You can even do it in a 3D program like Sketchup. This way you can start to think about some details that determine the way you will build your machine.
- For example, in the cutlist above, the cabinet bottom it too wide to be fitted between the four sides if 18mm material is used. That is because I want to route slots in the sides for the bottom to fit in.
- Also, think about how to join edges and corners in particular. You can put two sides squarly together, leaving you with a slightly uneven edge, maybe even a seam but it does not require to make miter cuts. If you do want mitered edges, I would suggest to cut the panels down to slightly oversized dimensions, and later on make the mitered edges to size. Again, MJR’s build guide has a great section on building the cabinet body and explains all of this in great detail.
- I wanted to keep the “waste” parts as large as possible as I was not entirely sure on how much I would need for remaining parts such as the playfield board.
Time to rip!
With the cut list in hand, it was time to start ripping and (cross) cutting. I do not have a wood shop, and you don’t need to. I used a circular handsaw, DIY straight cut jig and a framing square (not even a cross cut jig). Put down a reasonably flat surface and go to town.
I made sure to save just about every piece of scrap that I could find so that I had some spare material for mounting stuff later, or redo a piece if I messed up along the way.
As a non-woodworker, cutting down these two sheets this way took me the better part of a saturday. My motto was “measure
twice thrice, cut once”. And as I did so, I learned a few things about working with plywood:
- The top layer of veneer is extremely thin and splinters very easily. Not a big problem for a pinball machine as it gets painted and/or art work on it, but it makes for an uneven surface.
- Use a blade with many teeth to make the cuts as smooth as possible.
- When putting pencil marks on the stock, put it on the exact size you need it to be. With a straight edge jig lined up, it will cut exactly that line
- The side that you put the straight edge jig on top of, will splinter a lot less than the other side.
- If you are not an experienced woodworker, visualise the cut you are about to make. Yeah yeah, I know, I visualise a lot. But, in several occasions the power chord turned out to be too short to finish the cut because it snagged on the corner of the board or something.
And then, after a weekend’s work, I ended up with a pile of smaller plywood panels. The playfield and backbox side panels have diagonal edges, so I cut those as well and finally added some mitered edges for the vertical edges on the cabinet and left it at that.
Next up is cutting some grooves for trim pieces to fit in and since I want to make this machine a big light show; route slots for led strips. Lots of led strips. More on that in the next post.