Quest for the Ideal Fret Button Feel

I’ve spent a LOT of time and energy understanding the Guitar Hero fret buttons.  Different guitars have different dimensions. Not much different, but different enough. I try to balance fit, feel, weight and strength to get the best fret button feel I can.

35 Flavors

I’ve identified 35 measurements and parameters that fully define one fret button. I measure all 5 fret buttons, and take the average of the dimensions. I enter these into a spreadsheet, then import into my model in Fusion 360.

Even with my best efforts, the fit was never ideal. I wanted a design where the fret button was restricted to up-and-down only, so the fret couldn’t lean to one side and get stuck in the guitar neck. I needed to figure out how to engage the two rectangular holes on the top of the fret switches, but I could never guarantee exact-enough dimensions to have a one-piece fret button that will fit the requirement.

Two is Better than None

I considered one-piece frets, frets with shims, hollow frets you fill with something, longer frets, short frets, flat-bottom frets. I settled on a two-piece, glue-together fret button that solves the problem by engaging the keycap holes at the top of the actual switch, this ‘keycap’ will be super-glued to the fret button, and this locks the bottom of the fret so there is no side-to-side movement, only up-and-down.

One ‘keycap adapter’ is placed on each fret switch.

NOTE: The little black ‘keycap adapter’ is cemented/glued to the underside of the fret button, NOT glued to the fret switch.

Why Two Parts Instead of One?

This goes back to the difficulty of ensuring that the little keyboard switch is placed precisely in relationship to the hole in the neck, for all 5 switches, for all possible production variations in the guitars. I don’t have precise guitar design specs, I have to reverse engineer with the small sampling of guitars I have access to.  Close enough is good enough in this case.

The two part method allows for variations in dimensions and ensures an ideal fit between the neck and the fret and the switch.

Part 2 (yes, glue now)

8.  Test the ‘feel’. Ideally you want the fret switch to be pressed-in about 1 mm when the fret is NOT being pressed.
   The fret button should be held neatly in place by the spring within the switch.
   If the fret buttons feel too loose (e.g. they are not in contact with the keycap adapter, you can print keycap adapters of different heights until you get the feel you want.
   See the red asterisk in the drawing above. This dimension an be altered as necessary.
9. Press the frets to ensure movement without binding.
10. Remove the rubber bands or screws and separate the guitar neck.
    Remove the circuit board and fret switches, ensuring the keycap adapters are still attached to each fret switch.