On Thursday 14 May 2015 22:35:36 Gregg Eshelman wrote: > On 5/14/2015 8:03 PM, Gene Heskett wrote: > > So, compared to a timing belt (not actually needed, my encoder is on > > the load side of any slippage), the space for the input pulley is > > restricted to something just under 2" in diameter, how would the > > smallest 5 groove 12.7mm wide pulley/belt combo compare in terms of > > how much power it could move, when compared to the just barely above > > the KT boundary tooth profile the OEM pulleys and 10mm wide belts > > can move? > > I'd definitely do the mod to cap the bottom of the headstock to > convert it to a splash lube. > > Why buy a complete headstock instead of just new bearings and the > metal gears to put in the original while you mod it for oil bath? > > 'Course you'll also want an easy to access drain plug. :)
Yup. With a spare new one, I can take my time & do it a lot better than OEM. > If you want a more rigid connection to the bed, see if there's enough > metal in the hole-less corner to drill and tap a 4th hole. That will have to wait till I can inspect the bed under it. There is metal enough in the head casting I believe. I would suspect there wasn't room for the head of the cap screw when the 400 watter was in that pocket under the bed. Now my jackshaft assembly occupies that space so there is lots of air available now. > The 7x lathe not made by SIEG Industrial (formerly Shanghai Import > Export Group) is/was better in several details. > > Four headstock bolts instead of three. A heavier, rectangular saddle > instead of SIEG's H shape. Way wipers. A thicker apron with dual ball > bearings on the hand crank shaft. A locking adjuster nut on the right > end of the lead screw. Longer bed - prompting SIEG to offer longer > beds, including one even longer than the competition, which LMS sells > as an upgrade kit. > > The rest of it, pretty much identical to SIEG's 7x. > > That manufacturer also was using PWM motor control boards while SIEG > was still using a more primitive SCR chopper. Grizzly 7x10 #346 I > owned had a *very* primitive and quite buzzy control board, no > integrated circuits. One large resistor had been hot enough to > unsolder itself at one end. A little hit with an iron and it was back > in action. Quite poor low speed torque. > > The better lathe costs more and most importers that started with it > (like Homier) either switch to a SIEG version or quit selling a 7x > lathe. My first metal lathe was a Homier "Speedway" 7x12, chuck to > tailstock, between centers was 14". Unlike the common 7x10 which is > only 8" chuck to tailstock. The LMS bed upgrade stretches out to 14" > chuck to tailstock. > This one was a Homier "Speedway", purchased in middle of the '90's. Everything I've touched was a CF originally. I'd be hard pressed to call it a sow's ear as that would have been too high a complement. Since my chuck is a 5" 4 jaw now, I am not sure how one would measure the bed, but with this chuck at least an inch deeper than the OEM 3", it would be using a rubber tape measure to get it past the 12" mark from chuck to a live center in the tailstock. Its for sure not rigid enough to stretch it, not to mention I'd have to get another, 60-65mm longer z screw. But that doesn't answer the question re: is a polygroove belt better than this ancient timing belt? With the limited diameter of the drive pulley, I am tempted to make a larger polygroove pulley 5" or so in diameter, and use the space occupied by the change gears drive gear to mount the much larger polygroove pulley and drive it direct, taking the backgear shaft and gears plumb out of it. That too will be investigated, but it will take a bigger lathe than this one to make that pulley. Getting the spindle encoder remounted would be chapter 7 or so of this story... Thanks Greg. 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> ------------------------------------------------------------------------------ One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
