On Wed, 2014-02-19 at 21:26 +0000, Steve Blackmore wrote: > On Tue, 18 Feb 2014 20:59:08 -0500, you wrote: > > >Hi all; may be off topic, but am wondering about converting my Centec 2B > >mill to CNC. X,Y axes are relatively easy; Z is difficult. > > > >Is there any real need to convert the Z axis, assuming that the weight of > >the table will keep the backlash to a minimum, or am I way off base here? > > > >Thanks for any advice from those who may have gone down this path before > >me; > > Hi John - I had a Centec 2B with powerfeed and lots of horizontal > tooling. The important bits were tatty looking but in very good > condition under the grime. The X axis screw/nut design was pretty > appalling though. Getting the adjustment just right so it didn't jump > out of drive on reverse was a work of art. The table was heavy to raise > with lots of backlash in the bevel gears. I had the geared vertical head > too - that was very nice and had hardly been used. Some idiot had filled > the oil reservoir with grease and I had to strip it to clean. Getting > the bearing pre load correct after was difficult and I had to make a few > tools to do it. Fortunately the very expensive bearings were undamaged > and after fitting a new bottom oil seal it was fine. Guessing, I would > say that it leaked oil and to fix that they substituted grease! > > Although a very usable manual mill, I wouldn't attempt to CNC one. Not > an easy conversion. More importantly they are a bit "cult" over here and > fetch premium prices. I did renovate mine fully and repaint it before > selling it on and I made a hefty profit - you could buy a working second > hand Boss Bridgeport for what I got for mine! > > There are some details here. > > http://www.pilotltd.net/centec_2b_mill.htm > > please ignore rest of site - so out of date :) > > Steve Blackmore > -- Some years ago I put a servo on the W axis of my knee mill to substitute for a driven Z. At a geared half HP it was underpowered. I now have cobbled together a Z drive that is tight and repeatable. If I really wanted to fuss with it I would re-implement the W to set tool length, that way I would always have the full travel of the Z. At this point the Z has both a glass scale and an encoder just for confirmation and the W lives with a glass scale that has a display but no servo loop. Probably more than you waned to know.
Dave > > ------------------------------------------------------------------------------ > Managing the Performance of Cloud-Based Applications > Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. > Read the Whitepaper. > http://pubads.g.doubleclick.net/gampad/clk?id=121054471&iu=/4140/ostg.clktrk > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Managing the Performance of Cloud-Based Applications Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. Read the Whitepaper. http://pubads.g.doubleclick.net/gampad/clk?id=121054471&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
