[sdiy] Looking for model:samples rubber buttons

[Ben Stuyts]

On 26 May 2026, at 14:22, Ingo Debus via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
>> Am 26.05.2026 um 13:38 schrieb Ben Stuyts <ben at stuyts.nl>:
>> 
>>> Could this possibly be 3D-printed, maybe with TPU? That material can be quite flexible.
>> 
>> Not with an FDM printer (filament). If you can get it to print, it won’t be pretty and consistent.
> 
> Huh? Do you mean, TPU cannot be printed with a FDM printer in general?
> Or is there something special about these button mats that makes them difficult to print?

Apologies if I didn’t make myself clear. TPU can definitely be printed with an FDM printer. I do so quite often, so I have a bit of an idea of its limitations. TPU, TPE (or in general any flex) material is available in various shore hardness grades. Shore 95A is quite hard, and shore 60A … 82A are more elastic. The latter would be more suited for such a button. But it is also way harder to print than 95A. I have never been able to successfully (or repeatedly) print anything lower than 82A using various Prusa printers. The problems are things like:

- visible layer lines, and printing with lower layer height is not straight forward with flex on FDM
- buckling of the filament where it enters the hot end, or it wraps around the gears of the extruder (there are special hot ends / extruders to mitigate this)
- lots of under- / over-extrusion, you often have to tune your settings (temperature, speeds, retractions) per model
- stringing (lots of small strings of filament where the hotend crosses the printout). Can be removed afterwards but often leaves zits on the model.
- and in the end if you succeed, it’s prone to tearing and has a low life expectancy.

The more elastic the material, the more difficult it becomes to solve these problems.

Perhaps an SLA or SLS printer can pull it off, but I have no personal experience with that. It will look better, but I’m not sure how resistant it is to tearing or what the life span is.

Ben

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