DIY : DIY Robotron Cabaret Arcade Machine – MrVectrex – Medium
This is a how-I-did-it type guide to building an homage to a Robotron Cabaret Arcade machine.
I had completed building my first machine — a bartop arcade cab based on the design of the classic Nintendo Donkey Kong arcade machine (read about that here: Building an arcade machine) — and decided I wanted to make something a bit bigger — something you could stand at.
I tend to build machines based on other existing arcade machine designs, as I feel I lack the imagination to come up with a design myself, and anyway, the original machines where so iconic.
So I chose Robotron — this is a Williams game that is close to my heart and one I play a heck of a lot on my other arcade machine by utilising both player 1 and player 2 sticks.
The original Robotron machines came in 3 sizes: full size, cabaret (mid-size) and cocktail. I loved the artwork, colour scheme and shape and size of the cabaret version so decided that was the one for me.
I stuck together loads of A4 sheets of paper to make one really large sheet, laid it on the dining room floor and got to work with pencil and ruler and a piece of string (to make the arc of the cut out where the screen is).
I traced this onto 18mm MDF and then got busy with the jigsaw.
I had purchased a router “copy-bit” which I then used to make another side as a direct copy of the first by laying another sheet of 18mm MDF on top of the one I had cut and using the router+copy-bit to duplicate it.
I then used the same approach as I did with the other arcade machine build and glued and screwed batons to the sides.
I’ve been a bit remiss with photos of this particular part of the build, but I hope you can get the gist of it from these pictures taken at a slightly later stage.
Things where coming together nicely so far, but there was still a very long way to go.
I wanted to make sure the screen was mounted at a sensible angle and hence easy to see when playing the game.
As you can see in the picture below, I glued and screwed some batons inside the cab at the angle I wanted the screen to go at.
Also in this picture is the control panel. This was not the final size, but at least gave me an idea of the sort of room it would take up, and the sort of angle.
Here’s a pic showing the screen in place, mounted roughly just to give me an idea of whether the angle would work.
I was not going to be happy with just having the screen attached to those wooden baton rails, so needed to come up with a plan for something that would allow me to mount the screen in a removable component. Thus I’d be able to take it out for maintenance or replacement at a later point.
I came up with the idea of mounting it in it’s own “box” made of aluminium “L” shapes with aluminium “U” shapes glued to it for the perspex to slide into. Kind of hard to explain, so here’s a completed picture so you can understand what I mean.
So, back to how I made this.
I cut out some more 18mm MDF, wide enough to fit in the cab and tall enough to take the height of the monitor, mounted in a landscape orientation as that’s my preferred choice. I cut the center out of it so that the back of the monitor could drop through and the screen would then be closer to the wood and stick up less. Also this gives access to the connectors and power for the monitor from the rear.
I got “L” shaped aluminium and made a frame by cutting corners and drilled holes so it could be screwed to the MDF. I then cut “U” channel aluminium and glued that with 2-part epoxy to the aluminium frame I’d made. Clamps held those pieces in place while the glue cured for 24 hours. It looks a little like a picture frame without the glass in at this stage!
I made sure that the top piece of aluminium was bolted to the wood rather than screwed. This would be the piece that would come out to slide the perspex screen cover into.
Here’s a close-up of my rather poor corner jointing. Much of this was corrected with sanding and filling to get the corners to fit tighter.
Some more pictures of the back of the monitor mounting, a bit later in the assembly:
Note that the monitor was completely disassembled from the plastic case (which was discarded) and all extraneous pieces, such as the USB connectors, removed.
Credit buttons and coin door
I spent a long time researching how expensive it would be to get a genuine arcade machine coin mech to fit to the machine. Sadly I decided it would be just too costly. So opted for my own solution.
I found a cheap metal coin box door that had nothing but a hole for the lock and a security padlock (the mountings for the padlock got cut off and sanded back as they where not needed).
I then found some excellent illuminated square buttons that could take a paper insert. I use Photoshop to create a design at the correct size and printed it on normal white paper — the bright LED bulbs shine through this perfectly.
These buttons had microswitches which I could wire up and assign as credit buttons.
I drilled holes in the metal coin door for these buttons to be mounted in. Check the picture below — also note the metal brackets on the door for the security padlock, these got removed, as mentioned above.
This was the handy tool I bought to cut the correct holes in the aluminium door:
Securing the screen and control panel
Another thing that initially gave me sleepless nights was how I would secure the screen and control panel in such a way that they would not move about if the cabinet was relocated, but could be removed for maintenance.
I experimented a bit, but the solution I came up with used adjustable latches — see the picture below.
With these mounted in place on the screen and the control panel I could be sure that they where not going to move, unless I wanted them to.
This is the bit I really do not enjoy doing when making these arcade machines.
The endless sanding and spraying, the realisation that I’ve made a mistake and there is a run in the paint and I have to sand it back and try again.
I am not sure if it was the unusually dry and hot weather or just bad luck but I had so many times when the black spray paint would have a white “bloom” to it when it dried — forcing me to redo it.
I chose black spray paint for the front, back and top, and the sides are actually emulsion that has been paint-rolled on using a very dense foam roller. A strange choice it might seem, but it was more about the colour match than anything else.
Everything got sprayed with grey primer — as was used in my other arcade build, and then gloss black (again, as used in my other build).
First I masked off the sides and sprayed the front, top and back.
Then I reversed the process and masked the black gloss so I could paint the sides with a small, dense foam roller and a specifically chosen grey emulsion.
The back was also painted black, and then some slots cut in the door, for show really, but also to let some of the bass sound out from the speaker system I had planned. I covered the slots with aluminium vents to complete the look. I also put a lock on the back door, again for visual effect more than security (and to hold the door closed!).
As with my other arcade machine build, I wanted to be able to support 2 players and also be able to use player 1 and 2 joysticks together for Robotron. I opted for a set of sticks and illuminated buttons this time — unlike before, I fancied the idea of having glowing buttons on the control panel.
I actually used Photoshop to allow me to experiment with the layout and positioning of the buttons and sticks and printed a template onto white A4 paper sheets that would allow me to drill the holes in the correct places.
As with my last arcade build I planned on using perspex over the artwork on the control panel to protect it and also make the surface more durable.
The control panel was sprayed black — I later realised this was a little pointless as there was going to be vinyl artwork over the top, but at least it gave a clean finish for the vinyl to stick to.
I’m jumping ahead a little with the picture below, but this is what the wiring of the buttons and sticks looks like — at this stage, I had already applied the artwork and cut the perspex to fit.
Here’s the business side of the panel, with power applied so the buttons light up. Again, note I’ve jumped ahead here and am showing the control panel with the artwork and perspex in place.
BTW, I made the artwork myself in Photoshop, based off original artwork I found on the internet, but adapted to fit my button layout and control panel size.
I went to great lengths to get the design and printing of the side art right. So when it came time to apply it to the sides, I was really, really worried.
The first task is to position the art in the right place, then tape it there with low-tack tape (you don’t want to pull the paint off the side!).
There are 2 sides to the vinyl, or rather there’s adhesive on one side, protected by removable paper which you take off first and carefully position on the cab, and then you peel the outer layer of removable paper off VERY slowly and carefully, making sure you do not pull the vinyl back off the woodwork as you go.
Here’s what the sides look like with the art applied. I could not be happier with how this turned out! It really is perfect and exactly what I wanted.
I wanted the sound for this machine to be as good as I could get it. So after buying a PC 5.1 sound system from someone at work, I set about wiring it in.
The best part about it is the bass bin, which sits in the base of the cab and really kicks out some serious deep sounds.
However I needed to mount the 2 satellite speakers up above the screen, facing down, so that the sound was nice and clear.
I sourced some black mesh grills from eBay which I think work really well and look good. The black of the area around the screen means that you don’t really see the speakers at all as it all sort of “blends in”.
See the image below for a view of the insides of the cab and the bass bin.
Sorry for the rather chaotic cabling situation in this shot!
Pulling it all together
So the next few images are of the latter stages of the build where I was putting the finishing touches to things.
The image below is showing the screen module in place, this time, complete with the bezel artwork and the perspex.
This next image shows the screen and control panel in place and the initial stages of setup of Retropie — the front end for MAME on the Raspberry Pi 3 that powers the machine.
You can also see the artwork for the marquee in place and the marquee lighting powered on.
Note also the illuminated credit buttons on the front of the machine.
Here’s a link to a brief YouTube video I did of the cabinet:
That’s how I built my Robotron cabaret cabinet, which is powered by a Raspberry Pi 3. It really did take my quite a long time to build (about 11 months of the occasional evening and weekend work), but I tried my best to make it as tidy and complete as I could and frankly, I’m very happy with how it turned out.
I am definitely no expert with woodwork or electronics, I am a “tinkerer”, but I think as a result, I’ve demonstrated that anyone can make one of these machines if they have the time and inclination.
Thanks for reading!