On Monday 29 September 2014 05:47:49 andy pugh did opine And Gene did reply: > On 29 September 2014 03:35, Gene Heskett <[email protected]> wrote: > >> Apart from the extra cost, what is the drawback? > > > > The requirement for a totally backlashless coupling between the > > screws? > > I would imagine that a symmetrical belt drive from a single motor, or > two motors (and square it in software) would work. > > > OTOH that does seem like an awful lot of work as I'd still have a > > sows ear lathe. > > > > Bolton has an 11x28 (23 between centers) with a variable speed motor > > that sells bare for about $3000 USD. The B290VF. Marked down some > > now. $2721 w/6" 4 jaw & backplate. What can this group say about it? > > Good or bad? > > At that price, it sounds like the ear of a bigger sow. > > If you want a decent lathe, buy a $50,000 one. Just don't buy it new, > or pay that price.
There is an old Porter, circa 1908 or so, sitting out in the weather at one of the local wheeler/dealers. About a 12" chuck, and at least 60" long. Rusty but everything thats left moves. Designed to be driven from an overhead shaft. He wants $500 for it. But decent screws that big would cost at least a grand, and I'd need to build a spindle drive with probably a 5hp motor, and likely make a bunch of missing stuff, including the tailstock. Then figure out how to map the bed wear & rust back out of it, just didn't seem like I'd have enough time at my age, or money to finish it. Something in the 10 x 40 range would make more sense if I could stumble onto one at that price I'd break the guy's hand. Modern treadmill motors can be had rea$onable at up to 2.5 to 3hp. One of those could be handled by Pico's pwm driver if the toroids were beefed up a bit. Or even by its matching controller with another $200 in big relays and another 100 lines of hal to do a clean reverse. Screws would be half the cost, and the rest of it generally is just put your head down and git-r-done now that I have a better idea of what it requires. But I haven't stumbled onto one such yet, they aren't exactly estate sale items in these here parts. 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) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ Slashdot TV. Videos for Nerds. Stuff that Matters. http://pubads.g.doubleclick.net/gampad/clk?id=160591471&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
