If you are going to the trouble of filling a frame with epoxy then two things…
1) Why bother with the frame, just print a plastic mold and fill that. with epoxy. Then it will be the exact size and shape you need. 2) Don’t use epoxy as it is not very stiff, Mix the epoxy with glass fiber such that the fiber-to-epoxy ratio is as high as you can possibly make it. You don’t need expensive carbon fiber as you don’t care about weight. You want as much glass in the mix as possible. The usual way is to use woven glass, wet it with epoxy then use pressure from clamps or a vacuum pump to compress the part and push out as much epoxy as possible. But you can also mix chopped fiber with the liquid resin and make a paste. This is actually very low-tech and can be done with simple hand tools like paintbrushes and scissors. The problem is the same as with any new design, you have to make some prototypes and measure them and likey redesign them a few times. This is why people usually copy existing proven designs. > On May 20, 2023, at 11:28 AM, Gregg Eshelman via Emc-users > <emc-users@lists.sourceforge.net> wrote: > > You'd need to get a frame casting, set up indicators, then do some pushing, > twisting, and leaning on it to see how much it moves. > > What could stiffen it is filling all its internal space with epoxy. The upper > casting from one of these > https://china-highly.en.made-in-china.com/product/gSHxMeWyblRA/China-Hl-246-Long-Arm-Compound-Feeding-Super-Heavy-Sewing-Machine.html > could do the job since it bolts on from above it could be mounted over any XY > base you can build. > > Just might be workable for a wood router for sign carving. Z travel would be > limited to whatever vertical slide you mount, and if you space the arm up > higher. > > I'd expect that the really long ones with arms around 30 inches, would be > pretty well vibration damped in order to handle high speed sewing in heavy > materials like canvas. Sewing is mostly a short vertical motion. I'd assume > the main area of concern for adapting a long arm sewing machine to routing > would be resistance to bending sideways and twisting around the long axis of > the arm. > > > > On Saturday, May 20, 2023 at 11:00:22 AM MDT, Thomas J Powderly > <tjt...@gmail.com> wrote: > > I saw an overarm router recently > > and wondered if a sewing machine frame was stiff. > > Compared to a desktop gantry mill. > > > I imagined a makita router mounted on the over arm > > minimal Z travel ( 150mm at most) > > > I can find castings for industrial machines pretty cheap in qty 1 > > What i see are C frames, single casting, with base plate as long as over > arm. > > > Any thoughts? > > ( I don't have a sewing machine to lean on ;-) > > > _______________________________________________ > 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
