Tamiya 1/35 Renault UE Carrier - finally completed

[Tim Marlow]

Looks great Dave. A fun little vehicle I think.

[Dave Ward]

Gonna show my ignorance of 3d printing now, but what causes it to degrade ?

Polylactic Acid ( PLA ) can degrade through absorbing water, UV rays & temperature change ( apparently some bacteria can affect it as well ). It's produced by bacterial fermentation from corn starch, cassava roots, or sugarcane, is sustainable & renewable.
I've stupidly bought some old ( cheap! ) filament that was beginning to go off - it becomes inconsistently brittle - unusable. You store it in the dark, with silica gel sachets & kept cool & dry. New, it comes vacuum packed with silica gel
Dave

[Graeme C.]

Very nice Dave!:thumb2:

[Neil Merryweather]

I don't think it degrades much,if at all, after printing, Dave. I've been using it for about 10 years at work and I'm not aware of any of our models doing that

[langy71]

Polylactic Acid ( PLA ) can degrade through absorbing water, UV rays & temperature change ( apparently some bacteria can affect it as well ). It's produced by bacterial fermentation from corn starch, cassava roots, or sugarcane, is sustainable & renewable.
I've stupidly bought some old ( cheap! ) filament that was beginning to go off - it becomes inconsistently brittle - unusable. You store it in the dark, with silica gel sachets & kept cool & dry. New, it comes vacuum packed with silica gel
Dave

Thanks for the explanation Dave, I'd seriously got no idea why this happened... :thumb2:, doe's this happen with all types of filament ? or are the 'more expensive brands less liable to this happening ?
(Only concerned as the Mekon model I'm about to build for the tv GB has 3d printed arms)

[Dave Ward]

doe's this happen with all types of filament ? or are the 'more expensive brands less liable to this happening ?
(Only concerned as the Mekon model I'm about to build for the tv GB has 3d printed arms)

Neil, has much more experience with this - 10 years vs 10 weeks!, so I wouldn't worry too much about it!! I don't know about resin printed parts, that may be different again
Dave

[Neil Merryweather]

Neil, has much more experience with this - 10 years vs 10 weeks!, so I wouldn't worry too much about it!! I don't know about resin printed parts, that may be different again
Dave

The early SLA resins (circa 2000) were very prone to degradation, even after curing - so much so that standard practice in industry was to mould the printed parts immediately and cast in a polyester or polyurethane resin.
Alot of work has been done in the meantime to eliminate this, and to develop resins to mimic industrial plastics like ABS. Remember that the process was originally known as Rapid Prototyping.
The modern resins are entirely different, chemically, and are cured with different light types like uv, so I don't think it's likely to be a problem nowadays - especially with something sold commercially.

[grumpa]

Very nicely done Dave, even at 1/35 those smallish vehicles are a bit too fiddly for me at my age, but you pulled it off
superbly.

Jim.