[Emc-users] Y-axis calibration problem
Hello to all the gurus, I am facing a problem with my new built CNC platform. Before I describe my platform let me share a bit about my design. The platform is about 40x40 square using the ABEC7 bearings from CNCRouterParts (http://www.cncrouterparts.com/product_info.php?cPath=21products_id=33) to run the X and Y axis. The bearings run on 1/4 thick steel. I have a single lead screw driving the Y-axis that is positioned in the middle. I noticed that when I cut a 6x3 1/8 thick aluminum from sheet, the squares are are off by at least 1 degree that lends me to believe that my Y-axis deflects when cutting. My question is, can this deflection be removed if I move to round linear ball bearings running 45 on a 20mm shaft? I am trying to hold back on running my Y-axis using 2 lead screws one at each end and using 2 stepper motors. Any thoughts/opinions highly appreciated. Sam. -- This SF.net email is sponsored by Make an app they can't live without Enter the BlackBerry Developer Challenge http://p.sf.net/sfu/RIM-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Y-axis calibration problem
I have the X-axis of my gantry mill running on 600mm x 20mm round silver steel rods spaced about 3in apart using round linear ball bearings and, while it is acceptable for light routing, I get unacceptable deflection when drilling - I'm currently trying to think of ways to beef it up. I'm not too sure whether my problem is play in the bearings (they seem tight enough) or bending of the rods. Ian Shaffin Bhanji wrote: Hello to all the gurus, I am facing a problem with my new built CNC platform. Before I describe my platform let me share a bit about my design. The platform is about 40x40 square using the ABEC7 bearings from CNCRouterParts (http://www.cncrouterparts.com/product_info.php?cPath=21products_id=33) to run the X and Y axis. The bearings run on 1/4 thick steel. I have a single lead screw driving the Y-axis that is positioned in the middle. I noticed that when I cut a 6x3 1/8 thick aluminum from sheet, the squares are are off by at least 1 degree that lends me to believe that my Y-axis deflects when cutting. My question is, can this deflection be removed if I move to round linear ball bearings running 45 on a 20mm shaft? I am trying to hold back on running my Y-axis using 2 lead screws one at each end and using 2 stepper motors. Any thoughts/opinions highly appreciated. Sam. -- This SF.net email is sponsored by Make an app they can't live without Enter the BlackBerry Developer Challenge http://p.sf.net/sfu/RIM-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.851 / Virus Database: 271.1.1/3082 - Release Date: 08/19/10 19:35:00 -- This SF.net email is sponsored by Make an app they can't live without Enter the BlackBerry Developer Challenge http://p.sf.net/sfu/RIM-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Y-axis calibration problem
2010/8/20 Ian W. Wright watchma...@talktalk.net: I'm not too sure whether my problem is play in the bearings (they seem tight enough) or bending of the rods. I am sure that it is the bending of the rods. At least it was the cause for the similar case that I know of. Why don't You use more rigid structure - something like these profiles + supported slides? http://www.worldofcnc.com/products.asp?recnumber=81 That way the construction would be much stronger, and I think that existing structure of the router would require only minor adjustments. Viesturs -- This SF.net email is sponsored by Make an app they can't live without Enter the BlackBerry Developer Challenge http://p.sf.net/sfu/RIM-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Y-axis calibration problem
Viesturs Lācis wrote: 2010/8/20 Ian W. Wright watchma...@talktalk.net: I'm not too sure whether my problem is play in the bearings (they seem tight enough) or bending of the rods. I am sure that it is the bending of the rods. At least it was the cause for the similar case that I know of. I strongly agree with that ! I came to the same conclusing when experimenting during the construction of my gluing machine. If you need something rigid, I suggest you use supported rods like these (or bigger ones, of course) : http://cgi.ebay.fr/linear-bearing-slide-unit-2-SBR16-770mm-4-SBR16UU-/250518266038?pt=LH_DefaultDomain_0 -- This SF.net email is sponsored by Make an app they can't live without Enter the BlackBerry Developer Challenge http://p.sf.net/sfu/RIM-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Y-axis calibration problem
Shaffin Bhanji wrote: I noticed that when I cut a 6x3 1/8 thick aluminum from sheet, the squares are are off by at least 1 degree that lends me to believe that my Y-axis deflects when cutting. Are you sure your axes are truly orthogonal? The easiest way to check is to get a known-square machinist's square and lay it flat on the table. You align it with a dial test indicator until moving say the X axis shows no change in dial reading along the entire length of one arm of the square. Then move so the indicator can check the other arm of the square. You should again see no change in reading. If there is a change, then you need to move the travers of one axis relative to the other and recheck. Repeat until you get no deviation on either arm of the square. This will mean having to adjust the mounting of the rails. Of course, on such a large machine, you may have deflection. Taking one last finish cut with very small depth of cut may reduce the deflection. But, cutting a small piece out in the middle of your table, deflection would be much more likely to cause size error rather than cutting at an angle. Jon -- This SF.net email is sponsored by Make an app they can't live without Enter the BlackBerry Developer Challenge http://p.sf.net/sfu/RIM-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
