On Tuesday 26 November 2019 04:37:37 Chris Albertson wrote: > On Tue, Nov 26, 2019 at 12:47 AM Gene Heskett <[email protected]> wrote: > > Based on that, I have hungrily looked at the BS0 type devices, and > > wondered why no one has put a stepper drive on the index shaft, with > > sufficient geardown to resist cutting forces, > > I have a much lower price rotary table from LMS. But I think all of > them use worm gears and 72:1 reduction. The worm can't be back > driven so the motor has no cutting force to resist. Then you also > have a built-in 1:72 torque multiplier. You can use a small motor. > > But if you try that the motor sticks out way to far. It becomes more > compact if you use a timing belt and pulleys. and "fold" the motor > back 180 degrees. The design of this device is easy to make if you > already have the rotary table with 72:1 worm reduction. The belt > drive means no need for a flexible coupler or flexible motor mount. > amazon.com/Milling-Rotational-Dividing-Tailstock-Reducing > <https://www.amazon.com/Milling-Rotational-Dividing-Tailstock-Reducing >/dp/B07MDJNDNJ/ref=pd_day0_hl_147_6/140-1288918-2096269?_encoding=UTF8& >pd_rd_i=B07MDJNDNJ&pd_rd_r=1e9db8f9-bb53-4b4d-af6c-20b5d39b6f70&pd_rd_w >=3jOqX&pd_rd_wg=Ofpll&pf_rd_p=0501877d-5f8c-4ec8-9861-e0476eecc53e&pf_r >d_r=GFZ6P181ZWTHT3X6ZA1F&psc=1&refRID=GFZ6P181ZWTHT3X6ZA1F>
I already have a similar but scaled down design of a 4th axis. Came with the 6040. Its also fixed in a horizontal position. It has enough power to cut wood, and possibly delrin type plastics. Its also probably accuracy limited as I can turn it at about 20 rpm or more. I have equipt it with a home switch, so its the first, fastest homeing axis on my 6040. Not heavily used for anything but sharpening HSS lathe tools so far, very slowly as the spindles absolute maximum is a 1/4" shank, and no one makes a CBN wheel with a shank that small. I have one CBN wheel, but its a 5" diameter cup for a tool grinder. Not even close to ideal even in the 3k rev G0704 spindle. Diamond against HSS is a waste of time and diamond. So I wind up doing it on a bench grinder with a carbide wheel, slowly with a glass of water handy. Precise? Donbesilly. 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) 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
