[sdiy] I can print knobs!

[rsdio at audiobanshee.com]

Another idea used by a local Seattle 3D-printing shop is to print one mold that is the inverse of the desired item, and then mass produce by pouring into the mold. This allows ceramics (with powder-printed molds) or other materials. It's also much faster and more dependable than 3D printing, where a single glitch in the middle of a printing session can ruin an entire part.

For plastic knobs you'd need a mold that wouldn't melt when you pour liquid plastic into it. Maybe a ceramic mold made using the above process. Another challenge is that you'd need at least a two-piece mold to get the knob exterior and the space for the shaft. That's easy when 3D printing each individual item, but the quality always looks 3D printed. The molded technique allows the creation of items that don't look 3D-printed, but you then need to learn how to design multi-piece molds.

Personally, I find the rough texture of 3D-printed items to be distracting. It looks cheap and wrong. I wouldn't put a 3D-printed knob on a vintage synth because it wouldn't match. But a molded knob could easily get close enough to original that it might go undetected.


On Apr 29, 2017, at 1:49 PM, Vladimir Pantelic <vladoman at gmail.com> wrote:
> when you need precise dimensions you can also use the 3D print for the rough size and then post process it. e.g. I usually print holes undersized and then drill them to final size later. so e.g. if you need a press fit on a round shaft, print to 5.5 and drill to 5.9 for a 6mm shaft.
> 
> On 29.04.2017 20:52, Andre Majorel wrote:
>> Very interesting. Looking at the lack of detail in 3D printed
>> objects, I've always thought that 3D printers would be useless
>> for parts that must have precise dimensions... like press-fit
>> knobs.