On Wednesday 19 February 2014 15:40:19 John Alexander Stewart did opine: > Jon; > > OK, so you want to rig the Z drive to the quill, or the > > > knee? > > Knee. Apologies for responding before the coffee had kicked in, and my > ability to put thoughts down in text not cranked up. > > > I already > > addressed the knee part, so I can pretty much see the quill > > drive > > looks like a rack and pinion system. These typically have a > > LOT of > > backlash, and so are not a good choice for a live axis. > > I agree with this - the thought was to just lock the quill, and use Z by > the knee only. > > Interesting point about the Bridgeport quill arrangement; the Centec one > is more basic. > > I'll (attempt to) do some tests to see how well the knee moves this > weekend. As mentioned, generally, it's just locked into place and left > until it needs moving again (which can be months) > so I'm not experienced in using it for actually dialling in a cut. > > Thank you again - John.
Generally that movement is limited to a foot to 18" or so, and a big ball screw positioned under its rough center of gravity, and a couple heavy thrust nitrogen lift struts on each side of the screw to help it going back up, ought to get it to the point where a turning nut driven by a nema 34 should be able to do it as long as the speeds expected weren't too unreasonable. I can just barely make 34 ipm on my toy, moving the much lighter head up and down the square post with a clamped down quill with a nema 23, 425oz rated running the turning nut, but the motor psu is only 28 volts. 45 volts would make a huge diff. Bear in mind that you would need buckets of torque at driving a big drill bit at machinery handbook speeds though unless you also put something on the quill rack just for drilling holes, so the nema 34 should probably be at least a "double stack". And of coarse the turning nut means that nema 34 is hanging on, and is part of the weight of the knee to move. On my toy of coarse, I'm out of spindle power with only a 1/4" drill doctor sharpened 1/4" in the chuck. Sniff... But I can drive it cutting thin strips the first 3/4" deep before I start pecking & clearing. Just sayin... ;-) > ------------------------------------------------------------------------ > ------ 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.cl > ktrk _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene -- "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> NOTICE: Will pay 100 USD for an HP-4815A defective but complete probe assembly. ------------------------------------------------------------------------------ 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
