PLA for a control knob?
Hey everyone,
I'm looking to print some knobs for a guitar pedal. I want these knobs to last as long as a regular store-bought knob, many of which I believe are molded in ABS plastic.
I'd like to use a matte filament, and I see several matte PLA's available. I'm hesitant to use PLA for this though - I don't know how long the knob would last (doesn't PLA decompose?) and could be exposed to UV, moisture, etc.
RE: PLA for a control knob?
It would really depend on the rate of exposure, but it should last for a good amount of time, and you could coat / spray some clear coat on the knob to help keep out moisture but it would not be absolutely 100% sealed. You could run a test print with current PLA to check the fit and perimeter and infill settings to check to see if they would fit correctly before you go out and purchase filament for the project.
Shane (AKA FromPrusa)
doesn't PLA decompose?
Yeeeee eees - but not quickly. In a *hot* compost heap a typical print decomposes in two or three years. In cold compost or ordinary soil it doesn't show any degredation for many years. Ultraviolet light damages it quickly but kept sensibly PLA parts have a similar working lifespan to other plastics; I have some over ten years old.
The big plus is that PLA does, eventually, decompose and so does not contribute to the long-term plastic burden of the planet. That said, I expect a few PLA parts to become antiques in due course.
Cheerio,
RE:
I've done simple press-on control knobs on the I3 using PLA and in everyday use they hold up quite well.
I see no reason why ABS (or PETg or ...) could not be used.
Knobs that use a set screw will probably be more tricky, and many of the commercial ones of this type have a brass insert.