We need something really strong and durable, and the Cheetah fits the bill.  Not as good as NinjaFlex but still great.  I printed a sheet of NinjaFlex two layers thick, and I've yet to meet anyone who can tear it or break it.  So, we're trying it on the bolt (which is not really just a bolt: it is a bolt and a cleat all printed as one item) On 5/15/2020 6:13 PM, nop head wrote: > Why do you want a flexible bolt? > > I often have problems with flexible prints wobbling. I think it needs > a dual filament machine so it can print a solid core that could be > dissolved out if the result needs to be flexible. >

The smallest I have printed so far were M4 fasteners. M4 with a standard 0.7mm pitch is approximately a size 8-36 in imperial. I have done them before in PLA. The fasteners in the attached picture are M4 and M6 printed in generic PETG on a Prusa MK3 with a 0.4 hardened steel nozzle. Slic3r-PE 2.2 with a 0.5mm layer height, 100% infill. They all work fine right off the print bed and mingle well with actual steel parts. Regards, Jan <http://forum.openscad.org/file/t2836/DSCF6031.jpg> -- Sent from: http://forum.openscad.org/

Impressive but is "0.5mm layer height" a typo? Looks more like 0.05mm. On Tue, 19 May 2020 at 02:17, MostlyHarmless <jan@wi3ck.info> wrote: > The smallest I have printed so far were M4 fasteners. M4 with a standard > 0.7mm pitch is approximately a size 8-36 in imperial. > > I have done them before in PLA. The fasteners in the attached picture are > M4 > and M6 printed in generic PETG on a Prusa MK3 with a 0.4 hardened steel > nozzle. Slic3r-PE 2.2 with a 0.5mm layer height, 100% infill. They all work > fine right off the print bed and mingle well with actual steel parts. > > > Regards, Jan > > <http://forum.openscad.org/file/t2836/DSCF6031.jpg> > > > > -- > Sent from: http://forum.openscad.org/ > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >

Very impressive, I would suspect there is a really well set up system behind this. Cheers, RobW On 19 May 2020 7:10:04 pm AEST, nop head <nop.head@gmail.com> wrote: >Impressive but is "0.5mm layer height" a typo? Looks more like 0.05mm. > >On Tue, 19 May 2020 at 02:17, MostlyHarmless <jan@wi3ck.info> wrote: > >> The smallest I have printed so far were M4 fasteners. M4 with a >standard >> 0.7mm pitch is approximately a size 8-36 in imperial. >> >> I have done them before in PLA. The fasteners in the attached picture >are >> M4 >> and M6 printed in generic PETG on a Prusa MK3 with a 0.4 hardened >steel >> nozzle. Slic3r-PE 2.2 with a 0.5mm layer height, 100% infill. They >all work >> fine right off the print bed and mingle well with actual steel parts. >> >> >> Regards, Jan >> >> <http://forum.openscad.org/file/t2836/DSCF6031.jpg> >> >> >> >> -- >> Sent from: http://forum.openscad.org/ >> >> _______________________________________________ >> OpenSCAD mailing list >> Discuss@lists.openscad.org >> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >>

On 19 May 2020 7:10:04 pm AEST, nop head <nop.head@gmail.com> wrote: > > Impressive but is "0.5mm layer height" a typo? Looks more like 0.05mm. > Yes, 0.05mm of course. On Tue, May 19, 2020 at 5:35 AM Rob Ward <rl.ward@bigpond.com> wrote: > Very impressive, I would suspect there is a really well set up system > behind this. > The most important factors for this in my experience are proper belt tension, correct extrusion amount, slow speed and a level, very solid surface. I measure filament with an electronic caliper every now and then and adjust the thickness in the slicer. The printer is sitting on two 16x8x2 inch concrete pavers on a level drawer. All that together makes for precise walls with little oscillations and no bumps. As was said in this thread before, things get trickier as the screws get longer. I don't remember having printed an M4 longer than 20mm so far. The original question talking about a 5/16'' diameter I think anything up to 2'' length should work. Best Regards, Jan > Cheers, RobW > > On 19 May 2020 7:10:04 pm AEST, nop head <nop.head@gmail.com> wrote: >> >> Impressive but is "0.5mm layer height" a typo? Looks more like 0.05mm. >> >> On Tue, 19 May 2020 at 02:17, MostlyHarmless <jan@wi3ck.info> wrote: >> >>> The smallest I have printed so far were M4 fasteners. M4 with a standard >>> 0.7mm pitch is approximately a size 8-36 in imperial. >>> >>> I have done them before in PLA. The fasteners in the attached picture >>> are M4 >>> and M6 printed in generic PETG on a Prusa MK3 with a 0.4 hardened steel >>> nozzle. Slic3r-PE 2.2 with a 0.5mm layer height, 100% infill. They all >>> work >>> fine right off the print bed and mingle well with actual steel parts. >>> >>> >>> Regards, Jan >>> >>> <http://forum.openscad.org/file/t2836/DSCF6031.jpg> >>> >>> >>> >>> -- >>> Sent from: http://forum.openscad.org/ >>> >>> _______________________________________________ >>> OpenSCAD mailing list >>> Discuss@lists.openscad.org >>> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >>> >> _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org > -- Jan Wieck Principal Database Engineer

Did a little more testing. Credit where credit is due first: I am using Dan Kirshner's theads.scad v2.5 (found here: https://dkprojects.net/openscad-threads/). Printing even M4 in 0.1mm layer doesn't reduce functionality, but very much improves strength. The attached pictures are an M6x40 bolt with a 30mm shank (usually that sort of bolt has a shank). Best Regards, Jan On Tue, May 19, 2020 at 9:05 AM Jan Wieck <jan@wi3ck.info> wrote: > On 19 May 2020 7:10:04 pm AEST, nop head <nop.head@gmail.com> wrote: >> >> Impressive but is "0.5mm layer height" a typo? Looks more like 0.05mm. >> > > Yes, 0.05mm of course. > > On Tue, May 19, 2020 at 5:35 AM Rob Ward <rl.ward@bigpond.com> wrote: > >> Very impressive, I would suspect there is a really well set up system >> behind this. >> > > The most important factors for this in my experience are proper belt > tension, correct extrusion amount, slow > speed and a level, very solid surface. I measure filament with an > electronic caliper every now and then and > adjust the thickness in the slicer. The printer is sitting on two 16x8x2 > inch concrete pavers on a level drawer. > All that together makes for precise walls with little oscillations and no > bumps. > > As was said in this thread before, things get trickier as the screws get > longer. I don't remember having printed > an M4 longer than 20mm so far. The original question talking about a > 5/16'' diameter I think anything up to > 2'' length should work. > > > Best Regards, Jan > > > >> Cheers, RobW >> >> On 19 May 2020 7:10:04 pm AEST, nop head <nop.head@gmail.com> wrote: >>> >>> Impressive but is "0.5mm layer height" a typo? Looks more like 0.05mm. >>> >>> On Tue, 19 May 2020 at 02:17, MostlyHarmless <jan@wi3ck.info> wrote: >>> >>>> The smallest I have printed so far were M4 fasteners. M4 with a standard >>>> 0.7mm pitch is approximately a size 8-36 in imperial. >>>> >>>> I have done them before in PLA. The fasteners in the attached picture >>>> are M4 >>>> and M6 printed in generic PETG on a Prusa MK3 with a 0.4 hardened steel >>>> nozzle. Slic3r-PE 2.2 with a 0.5mm layer height, 100% infill. They all >>>> work >>>> fine right off the print bed and mingle well with actual steel parts. >>>> >>>> >>>> Regards, Jan >>>> >>>> <http://forum.openscad.org/file/t2836/DSCF6031.jpg> >>>> >>>> >>>> >>>> -- >>>> Sent from: http://forum.openscad.org/ >>>> >>>> _______________________________________________ >>>> OpenSCAD mailing list >>>> Discuss@lists.openscad.org >>>> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >>>> >>> _______________________________________________ >> OpenSCAD mailing list >> Discuss@lists.openscad.org >> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >> > > > -- > Jan Wieck > Principal Database Engineer > -- Jan Wieck Principal Database Engineer