Small ball endmills are available for reasonable prices. See https://www.ebay.ca/itm/154526476320 and https://www.ebay.ca/itm/152182318115 for examples from a vendor with whom I've been happy. Of course tiny ones may have insufficient reach to get to the bottom of your threads.
-----Original Message----- From: gene heskett <ghesk...@shentel.net> Sent: February 13, 2022 10:14 PM To: Enhanced Machine Controller (EMC) <emc-users@lists.sourceforge.net> Subject: Re: [Emc-users] need gcode maker On Sunday, February 13, 2022 6:22:05 PM EST ken.stra...@gmail.com wrote: > 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. I hadn't considered that, but you may be right about the stress risers, and they would fit just fine. I have 1/8" ball nose tools to try a short test cut with, and its worth the try. I wasn't thinking far enough outside the box. :o( A 2mm (or 3mm) ball nose would be icing on the cake. Thanks Ken. > -----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 > . 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
