It is not the epoxy that is so hard. It is the filler they mix with the epoxy. Many times it is a kind of glass, not unlike what they use to make sand paper. Other times they mix finely ground bits of steel.
I used to use a brand of epoxy that sold bottles of pure resin and cans of filler. I could mix what I needed for the job. Sometimes I'd use "micro balloon" filler these are tiny hollow balls of glass. A gallon tub of them weights about as much as an empty tub. Mixed to a thick paste, it cures to a foam you can and with a sure-form rasp. But if you mix the same resin with chopped fiberglass or chopped kevlar fiber it is as hard as stone and you'd need an angle grinder to smooth it down. I was building small boats and canoes. Yes epoxy can be damaged by UV light. If doing a gunstock, put 4 or 5 coats of exterior marine varnish over it. The marine stuff has UV blockers (sunscreen) in it. On Sun, Feb 13, 2022 at 4:20 PM gene heskett <[email protected]> wrote: > On Sunday, February 13, 2022 2:58:02 PM EST dave engvall wrote: > > With current technology wood glues ( epoxy ) are often stronger than > > the wood which allows one to machine short sections and glue them > > together for a composite piece that is as strong as a contiguous > > part. I think Gene is talented enough to make a live axis for his > > lathe that would do a bang up job of making those threads. Going thru > > the pain to do that is left as an exercise for the local shop. ;-) > > Nothing is impossible for the person that doesn't have to make it > > work. > > > > Dave > > There is another side to the epoxy glue story, well known in gunsmith > circles, the hardness of well cured epoxy dulling tools rapidly is well > known, something I found in the middle 1960's while finishing a laminated > walnut gunstock. It even plays hob with 600 grit wet-r-dry, wet. I had > to apply, and power buff to scratch it so the next coat would stick, 18 > coats of a clear epoxy gel coat intended for water ski's before I didn't > see the glue lines in the finish gloss. Now, nearly 60 years later, that > gel coat has turned pissy yellow, ruining the original tasty milk > chocolate color of the walnut under it. I've shot it a bunch, and after 4 > barrels chambered for Ackley-06, is now wearing a Bartlien SS 6.5mm about > 30" long chambered for Creedmoor and doing groups better than I can see, > sub inch the first time at the range. > > > On 2/13/22 10:32 AM, [email protected] 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. > > > > > > -----Original Message----- > > > From: dave engvall <[email protected]> > > > Sent: February 13, 2022 1:20 PM > > > To: [email protected] > > > 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, [email protected] 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 <[email protected]> > > >> Sent: February 13, 2022 12:26 PM > > >> To: Enhanced Machine Controller (EMC) > > >> <[email protected]> > > >> Cc: Robin Szemeti <[email protected]> > > >> 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 <[email protected]> > 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 > > >>> [email protected] > > >>> https://lists.sourceforge.net/lists/listinfo/emc-users > > >> > > >> _______________________________________________ > > >> Emc-users mailing list > > >> [email protected] > > >> https://lists.sourceforge.net/lists/listinfo/emc-users > > >> > > >> > > >> > > >> _______________________________________________ > > >> Emc-users mailing list > > >> [email protected] > > >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > _______________________________________________ > > > Emc-users mailing list > > > [email protected] > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > > > > > > _______________________________________________ > > > Emc-users mailing list > > > [email protected] > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > 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 > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
