On Mon, 8 May 2017 06:15:10 +0100 Luke Kenneth Casson Leighton <l...@lkcl.net> wrote: > On Mon, May 8, 2017 at 2:07 AM, <do...@mail.com> wrote: > > I apologize for DOS'ing the list, I can only get online about once a > > week. > > > > On Sat, 29 Apr 2017 12:42:29 +0100 > > Luke Kenneth Casson Leighton <l...@lkcl.net> wrote: > >> > >> On Sat, Apr 29, 2017 at 6:08 AM, Luke Kenneth Casson Leighton > >> <l...@lkcl.net> wrote: > >> > http://rhombus-tech.net/community_ideas/micro_desktop/news/ > >> > >> ok, ouch, onto the fourth revision of the corner-pieces already, and > >> some minor changes to the plywood are needed as well. this really > >> would have been awkward if someone else did it. > >> > >> the anycubic 3d printer is holding up well. the higher-quality PLA > >> from the company i found on aliexpress seems reasonable so far (the > >> "standard" quality definitely isn't: it literally crumbles under > >> pressure). > > <snip> > > > > Luke, (I can call you Luke, since you sign your name that way, right?) > > PLA stands for Poly-Lactic-Acid and if they are selling you something > > else you can complain, if not sue for false advertising. That's why we > > label things, so that we know what they are, right? So one PLA aught > > to be the same as any other. Aluminum is aluminum, titanium is > > titanium, why is PLA not PLA? > > it's partly down to where the lactic acid comes from: like any > chemistry you get a different yield and a totally different > composition depending on the process, the purity and the ingredients. > > most companies use corn for the raw materials, and they don't process > (purify) it properly. the result is that the PLA gives off acrid > fumes, deforms under pressure, does not adhere properly (to itself... > which is kinda important) and is generally completely fucking useless > for well... everything to do with 3D printing. Is there a way to tell how good a company is with their PLA? Price would not seem to make a big difference since companies can just charge lots of moo-la even with a poor product.
<snip> > ok, i'd like you to do a test. take a small piece about 5cm long and > bend it very very fast, as quickly as you can, making the loop as > small as you can (8mm or less if you can). > > good PLA will snap. > > shit-quality PLA will discolour, going light-coloured. > > another test - a really really important one - is to make a long > rectangle (35mm high x 5mm x 10mm would probably do) - the height is > important - then clamp one end to a desk. on the other end suspend a > weight tied with string as close to the end as possible. make the > weight... let's say.... 0.5kg or so. not very much. now leave it for > a month. <snip> Like this? +-+ <--- Rectangle | | +DESK++-+W <--- Weight | | | | | | Thanks, David _______________________________________________ arm-netbook mailing list arm-netbook@lists.phcomp.co.uk http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook Send large attachments to arm-netb...@files.phcomp.co.uk