Parametric arcade pushbutton

Introduction

Most 3d-printed arcade pushbuttons seem to rely a design where the button cap is only held in place by the stem that the switches cross-shaped connector slides into and is held there only by friction. I'm not very fond of this design as due to the shape of the connector the stem has to be printed in a bad orientation resulting in a fairly weak piece due to layer lines. Also it is somewhat difficult to get the measurements right so the cap stays in place during fierce gameplay.

This pushbutton design solves the issue by placing the button cap inside the button housing. The cap still fits on the cross-shaped connector on the switches as this way the caps stay in the middle of the button housing. This greatly reduces the friction between the housing and button cap. The housing also restricts how far up the button cap can raise and as such it is possible to create buttons where the pre-activation travel is shorter than in buttons where the button caps are only connected to the switch.

This design uses regular sized keyboard switches. The most usual button sizes in arcade fightsticks are 24 mm and 30 mm but this design can be used to create buttons of other sizes as well. 24 mm is the smallest I've tested but it might be possible to make 23 mm buttons work. There is not much sense going smaller than that anyway as with round buttons the switch itself restricts how small the parts can be made. The largest button I've tried is 40 mm and while it didn't feel as nice as a 30 button it was still serviceable. This design might be for you if you want to make a controller with one or more very large buttons.

For the threadings I've used code from quickthread.scad by Arpruss that can be downloaded
from their github page.

To get reliable and easy to solder connection this design uses Outemu switch sockets. Other brands might work as well but the sockets might be loose or not fit into the holes. The sockets are not 100% necessary but they are much easier to work with and with them you don't have to solder the wires directly into the switches which means that it is easy to swap switches if you want to.

Printing instructions

I've prepared stl-files for 24 mm and 30 mm buttons. For other size buttons you will have to render the pieces in Openscad yourself. The comments in the .scad file provide information on the few variables you can change. I'd recommend checking them out even if you only want 24 or 30 mm buttons. The pre-rendered pieces have 1.0 mm of cap restriction which should work with most keyboard switches. For a complete button you will need the following pieces:

1. cap
2. housing
3. fill
4. bottom
5. ring
6. socket holder and 2 pcs 2x5 mm screws to attach it (optional but recommended)

The ring part tightens the button in the panel it is attached to. While doing this it also keeps the whole construction of the button together. Because of this you will have to choose the right ring-file depending on your panel thickness. It is better to use variant that is for slightly thicker panel than what the panel actually is because it is more important that the button construction is tight than how tightly the button fits around the panel. The ring is the only piece which changes in size based on the panel thickness so it is easy to create a ring stl with the .scad file if you need a ring for some mid-sized panel (like 2.5 mm for example).

All the parts can be printed without supports as long as your printer can handle 45 degree overhangs. As the housing part contains some very thin walls use a 0.4 mm nozzle (or finer).

I don't have a resin printer and I have no experience of using one so this design is intended for fdm-printers. I don't see why this design wouldn't work with resin printers but maybe I'm missing some detail on how they work.

Assembly instructions

1. Attach the button cap to the switch.
2. Push the switch into the fill-piece.
3. Attach the switch socket into the bottom part.
4. Carefully align the switch pins with the socket's holes and push the pins into the socket. You will likely have to hold the socket in place while doing this.
5. Push the housing part through the hole in the controller's panel.
6. Place the whole assembly into the button housing.
7. Screw in the ring so the ring is keeping all the other pieces firmly in place. Note: At this point the button should also be fairly tightly around the controller's panel. If it is not tight enough adjust the PANEL_THICKNESS variable and reprint the ring-part.
8. (Optional.) Attach the socket holder to the bottom of the button so it holds the switch socket in place. This piece also has holes for the wires to go through. Use two 2x5 mm screws to attach the socket holder.
9. Solder the wires into the socket holder.

The included pictures also contain an image that shows an exploded view of the button and in which order the pieces should go together.