What I like about linear motors is the non-contact, low maintenance, no backlash, high speed, and high accuracy. It may be overkill, but I like that. The extra speed may be useful for thin soft materials and reducing slew time when cutting lots of holes. The extra accuracy may be helpful in doing just a little better than typical waterjets. The main problem with waterjets is the water and the fine mist of abrasives that travels into the bellows. Other problem are inaccuracies in the width of the cut (kerf) due to abrasive flow, speed changes, cutting head offset above the material (usually about 1/16 inch), and vibration of the table and part. Add it all up and you are soon wishing for no backlash and infinite accuracy from your motion system just to gain some sanity. Since I don't want a 16ft ballscrew or belt drive system on the long y-axis I am designing, I think a rack and pinion would be my next best option. I don't want to take a chance that this would wear out quickly and start showing backlash. Does anyone know what the difference in price between a high accuracy rack and pinion and a low accuracy linear motor would be (+/-.0005 inches or better)? If I had enough incentive, it wouldn’t be too late to reconsider a cheaper drive system with adequate specs. John
> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > Stuart Stevenson > Sent: Saturday, September 29, 2007 10:14 AM > To: [email protected] > Subject: Re: [Emc-users] linear motors with EMC > > Why would you use liinear motors on a waterjet? The speed > and accuracy needed would allow you to use a much less > expensive drive system. > I ask this to educate myself. I have never used a > waterjet. I am sure I don't know and understand the waterjet gotchas. > I understand doing it because you want to. > thanks > Stuart > > -------------------------------------------------------------- > ----------- > This SF.net email is sponsored by: Microsoft Defy all > challenges. Microsoft(R) Visual Studio 2005. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.488 / Virus Database: 269.13.33/1036 - Release > Date: 9/28/2007 3:40 PM > > No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: 269.13.33/1036 - Release Date: 9/28/2007 3:40 PM ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
