On 2/21/2014 12:01 PM, dave wrote: > 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 please ignore rest of site - so out of date :) 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
Dave, Was your knee counterbalanced - for example: a Bridgeport Series 2 - or not? 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
