On Thu, 2013-06-13 at 00:43 +0100, andy pugh wrote: > On 13 June 2013 00:22, Kirk Wallace <kwall...@wallacecompany.com> wrote: > > > If I may, my vote would be to restore the Rivett back to the original > > condition. It seems to me to be the shortest path to having something of > > value. If you need a CNC lathe, sell the Rivett, and buy an HNC or CHNC > > which would be a much better CNC project, but I'm biased. > > I already have a CNC lathe, though I mainly use it for one-off and > experimental style work. In fact the CNC aspect for me is mainly an > extension of conventional power feed that returns to the start point > and takes another cut until completed. I do 95% of the things I do on > the lathe just using the same 6 macros. > > So, I have concluded that what I need is a conventional lathe, with a > large spindle bore, a set of rests, and that will fit in a small > space. In fact what I need is probably a Harrison M250, or better > still the M280 CNC trainer version. > > I only really bought the Rivett because they have fascinated me since > I saw them on the lathes.co.uk page. I paid £120 for it, which at the > moment isn't a great sum of money to me. I spent £99 on a ballscrew > for my milling machine only a week ago. > > However, I do want to make the Rivett useful and usable again. It was > bought as "for parts or not working" and I am determined that it won't > leave me in the same state. > It needs a motor and drive system, and underdrives always look neatest > to me with the flat-bed lathes, so that is decided. > > I don't have any of the changewheel or screwcutting gearbox parts > (other than the quadrant). Finding the parts seems unlikely, certainly > at a sensible cost. > > What would make a lot of sense would be to replace the original > changewheel arrangement with an electronic leadscrew drive. (this > could easily be a second motor inside the cabinet, and a toothed belt > drive, and would be effectively invisible. This could be nothing more > than an Arduino with an LCD display. Add three gear-tooth sensors > inside the backgear cover, and the machine suddenly becomes quite > useful. (Though I am also short of a threading indicator) > > Hi, In a mild fit of madness I thought about offsetting the spindle and the tailstock several inches in X and an inch plus in Y to emulate a slantbed. Thinking back on the whole project I should have just built a lathe with a decent bore and very responsive Z and X designed to do threading on (rifle) barrel shanks. Ah! Hindsight is such good stuff. ;-)
Taper, etc can be done nicely on a standard lathe. Dave dave ------------------------------------------------------------------------------ This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
