On Monday 26 October 2009, Hubert Bahr wrote: >Gene > From the drift in this thread it sounds like you have an X2 using >stock screws. In my case I abandoned the stock screws and went with >lower cost rolled ball screws. I decided the X2 wasn't rigid enough to >justify precision screws. Of course at 5 tpi I get plenty of >longitudinal motion without super high rotating speeds. I used .625 >inch screws. I did have to remove some metal for clearance on the >table, saddle and base. I chose to move on to an X3 as it would provide >more rigidity and X, Y and Z motion. There, I am still using the stock >screws, just until I get some other things under control, like emc2 >control of spindle speed and change to belt drive for greater speed >range. I already have the screw stock and nuts on hand, It is just >things are working well enough that the other changes take higher >priority. I did find the X3 much easier to convert although the Z axis >takes a much larger motor. I guess I am confused at what kind of speed >you would have on the Y axis with less than 4" of travel that would >cause bearing noise.
I don't believe its bearing noise, but the screw chattering in the nut. And I have, with the LMS table kit, about a 5.25 by ~12" motion envelope, so it can do its current G0 speed of 25.2"/min with less than a 3 turns of the motor accel ramp. I re-designed the z axis completely, and with a 425 motor on the z screw with a 17/42 belt reduction, I can now put 155 pounds on a drill bit, whereas with a 262 on the original setup, the head gibs bound and locked at about 5 pounds. Screws behind the post are a very bad design unless the z ways are 2 or 3 times longer. But you are right about the rigidity, its rather sorely lacking, as one would expect in a sub 100 pound machine. With all my mods, it might weigh 100 lbs now, but the basic frame is still as flexible as ever. Thanks Hubert -- 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) The NRA is offering FREE Associate memberships to anyone who wants them. <https://www.nrahq.org/nrabonus/accept-membership.asp> Monday is an awful way to spend one seventh of your life. ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
