Another possibility would be to make a good approximation to the desired buttress thread using a ball endmill. Mount the stock horizontal on your 4th axis and make multiple passes with the ball endmill with each pass being deeper and nearer to the vertical wall of the buttress thread. Of course the root of the thread would be semi-circular rather than sharp but that is probably a plus to reduce stress risers.
-----Original Message----- From: gene heskett <ghesk...@shentel.net> Sent: February 13, 2022 5:46 PM To: Enhanced Machine Controller (EMC) <emc-users@lists.sourceforge.net> Subject: Re: [Emc-users] need gcode maker On Sunday, February 13, 2022 1:32:05 PM EST ken.stra...@gmail.com wrote: > Thread milling would be a good approach except that I doubt that Gene > has 18-inches of Z-clearance on his small mill to thread the length of > his desired screw plus spindle clearance to mill to the table might be > an issue. Yes, one of the reasons for the tiny harmonic drive is the clearance for the gantry to pass over it. The drive is mounted coaxial to the motor on the other side of the motor mount bulkhead of the assembly, and the gantry bottom clears it by about 1/8" going by. Only 85mm in diameter. That won't be a problem in this instance as the drive will actually be bolted to a shelf stuck to the rear of the base frame, with only the chuck projecting over the bed, ditto the tailstock stuck to the front of the base frame left of the Y motor at the same x offset. That should leave room for a hard maple stick around 21" long to carve into a bolt. Final length TBD of coarse. All driven by the relatively low bending moment on the stick from a 20k rpm bit vs a shaped bit in the sheldon turn at 250 rpms. That would demand a much sharper tool, probably not maintainable for one full sweep the length of the stick. Thanks Ken, take care & stay well. > -----Original Message----- > From: dave engvall <dengv...@charter.net> > Sent: February 13, 2022 1:20 PM > To: emc-users@lists.sourceforge.net > Subject: Re: [Emc-users] need gcode maker > > Other options for buttress. DIN | ANSI .. Either grind a tool out of > M2 or equivalent or go shopping for inserts on the web surplus sites. > They won't be cheap but a bit less hassle. Single point thread mill?? > Lathe sound easier than milling it. > > Dave > > On 2/13/22 9:37 AM, ken.stra...@gmail.com wrote: > > Alternatively one can tilt the stock rather than the head which I > > believe is Gene's plan. > > > > -----Original Message----- > > From: Robin Szemeti via Emc-users <emc-users@lists.sourceforge.net> > > Sent: February 13, 2022 12:26 PM > > To: Enhanced Machine Controller (EMC) > > <emc-users@lists.sourceforge.net> > > Cc: Robin Szemeti <ro...@redpoint.org.uk> > > Subject: Re: [Emc-users] need gcode maker > > > > If you can tilt the head at an angle, then something as simple as > > "G1 > > X300.00 B30.00" will do it, depending on how you have configured the > > B axis. If you can't tilt the head, no amount of GCODE will help > > you. > > > > I'd just do it on the lathe ... > > > > On Sun, 13 Feb 2022 at 16:54, gene heskett <ghesk...@shentel.net> wrote: > >> Greetings all; > >> > >> I have composed a simple butress thread in OpenSCAD, which can save > >> many formats besides the .stl's I feed cura with. Those choices are > >> shown in this list: > >> STL > >> OFF > >> WRL > >> AMF > >> 3MF > >> DXF > >> SVG > >> CSG > >> PDF > >> image (png) > >> > >> The latter being what you see in the attached png images. > >> > >> What is out there that can make gcode out of one of those formats, > >> assuming I can do some creative editing to make the bolt code carve > >> an 18" bolt from a hard maple 2x2 being spun by a B axis as Y > >> slowly advances with aux tables to make the Y axis long enough on > >> both ends on my 6040 mill, and I till use a 60 degree engraving > >> mill in it with a 30 degree wedge under the motor mount to tip it > >> to make the 0 degree load face of the thread with the side of the > >> tool's V. I intend to make the wedge as a hinge if I can print it > >> rigid enough. > >> And PETG seems like it could be the Right Stuff. > >> > >> The target of all this tom-foolery is a wood workbench vise screw. > >> The 2nd half nut is about half done on my BIQU HX printer as I send > >> this. So its beginning to look do-able. > >> > >> I faintly recall that inkscape had a gcode generator plugin at one > >> time, does anyone have a clue how well it works or if it even > >> exists > > > > today? > > > >> Synaptic does not look promising but I installed inscape and > >> friends anyway, and of coarse pycam, and I just found dxf2gcode, so > >> that got installed. > >> > >> Does anyone else have a better idea? > >> > >> Thanks All; > >> 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, 1940) > >> 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 > > > > _______________________________________________ > > 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 > > _______________________________________________ > 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 > . 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, 1940) 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 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
