It's not that odd at all. Accretion of material in the nozzle, wear and tear on mechanical parts, stress on parts from repeated heating and cooling, temperature and humidity differences between prints, the shelf life of materials, and the basics of probability theory and random distributions explain what we observe. Our g-code programs result in consistent instructions fed to a machine whose state is expressible only as a probability distribution function. Expecting results only in the "acceptable" part of the function's range is akin to entering a casino with pocket change, hoping to exit with life-altering wealth. ;-P On Tue, Aug 23, 2022 at 8:56 AM nop head <nop.head@gmail.com> wrote: > I print most plastics on glass by using a very hot bed temperature for the > first layer and then dropping it below Tg after that. 100C for PLA first > layer, 130C for ABS. I do need glue for PCL and Nylon though. > > Ny nozzles are mostly J-heads more than 10 years old and the > aperture doesn't get bigger, it gets smaller over time due to the build up > of carbon glaze and has to be reamed back to size with a drill. > > I can't really polish the nozzle because the carbon glaze won't just rub > off, even when hot. I would have to abraid it off and it would soon reform. > > It is very odd but in the 3D printing world nobody seems to get the same > results. Especially with bed materials and preparation. I have had no luck > with recommended hair spray or pledge polish and numerous other bed > materials. > > On Tue, 23 Aug 2022 at 12:52, jon <jon@jonbondy.com> wrote: > >> I print PLA on my Prusa all of the time. I use their textured print >> surface sprayed with hairspray. >> >> Jon >> >> On 8/22/2022 11:53 PM, edmund ronald wrote: >> > I believe nozzles are precision parts but cheap. >> > I got a prebuilt Prusa. It worked out of the box with PLA but not >> > especially well - prints came unstuck, spaghetti etc. >> > I learnt to wash the base board with hot water and detergent, did some >> > calibration, that improved things but the prints were never really >> > nice and the thing was temperamental . >> > >> > And then for some reason I decided to print PETG. I got a textured >> > baseboard and some PETG from Prusa, and ran a calibration, the prints >> > are wonderful,l it just works. All I can say is the thing seems made >> > for printing PETG, it is rock solid printing PETG, which by the way is >> > the material is a lot of its parts are printed from. I just printed a >> > part after the printer had been idle for 3 months and it printed >> > perfectly. >> > >> > Moral of the story - I think one should get a printer that does a >> > certain job well and is known for it, and just do that one thing, do a >> > calibration, lock down the settings and forget about changing >> > materials etc, that is a recipe for endless fidddling. >> > >> > Edmund >> > >> _______________________________________________ >> OpenSCAD mailing list >> To unsubscribe send an email to discuss-leave@lists.openscad.org >> > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org >