Round performance pad ?

[MonsieurLam]

Hi guys,

I'm looking for a specific spare part : a round performance pad. Hard to find, as close to all MIDI controllers use square / rectangular pads (MPC, Maschine, Ableton Touch etc.)
Here's a quick drawing of what I'm looking for:

roundpad2.jpg

Just think of the beautiful child of an MPC Pad and an Arcade Stick button.

Any lead on this? Thanks for your help!

[the_bastet]

Round performance pads do exist, but they do tend to tear over time. I dont know the exact physics, but I think it has to do with the distribution of stress/force across the material.

[MonsieurLam]

Thanks for the feedback, didn't knew the shape could weigh on sturdiness

[padi_04]

Round performance pads do exist, but they do tend to tear over time. I dont know the exact physics, but I think it has to do with the distribution of stress/force across the material.

Care sharing an example of a device with circular pads that failed on you or a mate? Not trying to pick a fight, genuinely curious.

I would assume it would be the opposite since a cylinder would take the compression more evenly and quite a few gaming controllers have rubber round buttons too. Maybe the main reason they aren't popular is just that square ones have a larger action surface so it's quite easier to hit.

Regardless of shape rubber does degrade over time but it would be super interesting for someone with proper knowledge on the matter to chip in with info wether this would be a factor to alter it.

[the_bastet]

Care sharing an example of a device with circular pads that failed on you or a mate? Not trying to pick a fight, genuinely curious.

I would assume it would be the opposite since a cylinder would take the compression more evenly and quite a few gaming controllers have rubber round buttons too. Maybe the main reason they aren't popular is just that square ones have a larger action surface so it's quite easier to hit.

Regardless of shape rubber does degrade over time but it would be super interesting for someone with proper knowledge on the matter to chip in with info wether this would be a factor to alter it.

No devices that I have owned. Just something we found when 3D printing rubberized buttons. The square (rounded corner) buttons took a pounding, but the circular buttons would start to crack around the edges. I think it has to do with how the stress is applied to the general surface area. On the square button, there is more distribution across the base of the button where the circular button was applying more stress to the top ridge of the button.

When you look at the button, think about it in 3 dimensions. Im sure there is a way to adjust the design to make a strong rubber circle button, but that is beyond my current design level at the moment.

[padi_04]

gotcha

[MonsieurLam]

So I'm back to square one. I wish I could find a "rubberized" arcade stick button...

[nem0nic]

Maybe roll your own? You could get this done with a 3D printer, some mold-making items, and an FSR (like this one - https://www.adafruit.com/product/166). I would recommend silicon for the injection material.