First, It bears repeating that the printer I’m using is Not a “normal” one. Stratasys Dinension Elite, can’t print pla because it burns it up while loading and clogs the nozzle with carbon, works best to print ABS with hot end temp at 275C, runs enclosure temperature at 75C, and uses a proprietary Stratasys slicer. The non-interchangeable nozzle is about 0.2mm. Raster width options are from 0.35mm to 0.95mm. Layer height has 2 options: .17mm or .25mm.
So yes, layer height on this printer is always less than line width. Maybe it works due to the hotter-than-normal hot end temp? It’s a big, old, one-trick pony but it does that one trick really well; consistently print dimensionally accurate ABS parts. > On Jun 2, 2020, at 4:58 PM, Chris Albertson <albertson.ch...@gmail.com> wrote: > > I don't think "squashed" is the word. That would mean the line width is 2X > wider. The way it works is a 0.4mm nozzle flies maybe 0.2 or 0.1 mm > over the surface and the gape is filled with hot plastic that is metered > out at exactly the same speed the nozzle flies. It should not print wider > then the nozzle width. But I think it does a tiny bit. > > This is one reason not to use 0.2mm nozzles, the layer thickness would have > to be 0.1 or less and then the line width is only 1/2 as wider. It would > take days to make a print. > >> On Tue, Jun 2, 2020 at 1:58 PM Thaddeus Waldner <thadw...@gmail.com> wrote: >> >> I think your end mill cutter analogy is useful. What I would add is that >> in order to get good layer adhesion, the actual width of the 3d-printed >> track needs to be slightly “squashed” by the nozzle as it is placed. A >> good rule of thumb in my experience is to use somewhere between 2-3 times >> the nozzle diameter and no less than 1.5 times the nozzle diameter. >> >> My experience might not be universal, since I’m using an old Stratasys >> with a heated build envelope and print mostly ABS. AND I can’t change out >> the nozzle. >> >>> On Jun 2, 2020, at 3:37 PM, Chris Albertson <albertson.ch...@gmail.com> >> wrote: >>> >>> I just printed a set of 3mm pitch GT3 timing pulleys with my 0.4 mm >> nozzle. >>> They came out just fine. >>> >>> The final profile of the pulley tooth is not determined by the >>> nozzle diameter it is limited by the step size on the printer. My >> pulley >>> fit the belt well enough that tooth shape is not the limiting factor. >> On >>> my case it is runout, not tooth shape that will cause the greatest error. >>> >>> Think of an end mill cutter. I can make sharp corners with a 12mm >> diameter >>> end mill. What I can't do is make less then a 6mm inside radius. Same >>> with the nozzle but backwards. A 0.4mm roud nozzle can make at best a >> 0.2 >>> radiu corner while the 0.2 nozzle can print a 0.1mm radius. But the >>> printer steps are that size and introduce a larger error than the nozzle. >>> In any case what you really care about is error in motion transfer >> between >>> the pulleys. Runout matters but a tiny radius error on an outside >> corner >>> does not change how the belt sits in the pulley. >>> >>> There is a big disadvantage to 0.2 nozzles (1) they clog up and need >>> cleaning and (2) printing is about a lot slower. >>> >>> Your first step before printing pulleys is to print a cube. Use CAD >>> software so you know the exact dimension you specified, run it trough the >>> slicer, print and measure all sides and angles. Get those >>> measurements good enough. >>> >>> When designing with plastic, you have to make stuff bigger. Use the >>> largest pulleys that will physically fit and this keeps the percent error >>> down. >>> >>> I any case my A6 primer is the same as your Ender except mine uses ground >>> steel rods for track and yours uses extrusions, But everything else is >> the >>> same all down to the Merlin firmware. My 3mm pitch by 9mm wide GT3 >>> profile pulleys came out pretty good. I had to make the flanges >> wider >>> as the aluminum pulley design has tapered flanges that came to a point. >> I >>> made them thicker and blunter and used a 20mm center bore. Odd that I >>> could print the tooth profile just fine but not the flanges. >>> >>> >>> >>> >>> On Tue, Jun 2, 2020 at 10:26 AM Gene Heskett <ghesk...@shentel.net> >> wrote: >>> >>>> On Tuesday 02 June 2020 12:50:54 Karl Jacobs wrote: >>>> >>>>> Gene, just make it executable and run the appImage. I use Cura to >>>>> slice for a Delta-printer and use LinuxCNC (actually, Machinekit on a >>>>> Beaglebone) to drive the hardware. Marlin on Arduino hardware works >>>>> nicely too, of course. Good luck with 3D-printing, just needs the >>>>> usual learning curve. >>>>> Karl >>>>> >>>> Which for my ancient 85 yo wet ram seems pretty steep, but I think I >> have >>>> the top of this hill in sight. That 3d cat is printing now... :-) Ought >>>> to be done by dinner time. >>>> >>>> I think I need to find some .2 nozzles before doing any XL timing >> pulleys >>>> though. Thats about next. Then I suppose I'll appreciate the speed its >>>> doing now. >>>> >>>> Thanks Karl. >>>> >>>> Cheers, Gene Heskett >>>> -- >>>> "There are four boxes to be used in defense of liberty: >>>> soap, ballot, jury, and ammo. Please use in that order." >>>> -Ed Howdershelt (Author) >>>> If we desire respect for the law, we must first make the law >> respectable. >>>> - Louis D. Brandeis >>>> Genes Web page <http://geneslinuxbox.net:6309/gene> >>>> >>>> >>>> _______________________________________________ >>>> Emc-users mailing list >>>> Emc-users@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>> >>> >>> >>> -- >>> >>> Chris Albertson >>> Redondo Beach, California >>> >>> _______________________________________________ >>> Emc-users mailing list >>> Emc-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> >> >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > > > -- > > Chris Albertson > Redondo Beach, California > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
