John: Thank you again for the rapid response. You're right I left out some important information. Your guesses were dead on though, 5TPI lead screws, 2:1 reduction, and 200 step/rev motors.
It sounds like I'd have some 50% buffer in step generation under these conditions. This sounds good to me so I'll go with the 10 ustep Geckos. I can get add on step multipliers if we're terribly wrong but I should be OK. Thank you again. I'll let you know how it works out. On Sunday August 5 2007 4:17 pm, John Kasunich wrote: > To figure this out you need to convert inches per minute to steps (or > microsteps) per second. To do that you need to get the machine data > and do some math. > > I think in your last post you said it was a Bridgeport (or clone). That > probably means 5 tpi screws. You also said something about 2:1 ratio > between motor and screw. So that gives you 10 turns of the motor per > inch of travel. > > I'm assuming you have 200 step/rev motors. At 10 turns per inch, that > means 2,000 full steps per inch. With 10x microstepping drives, you > will need 20,000 microsteps per inch. Forty inches per minute is 40/60= > 0.66 inches per second, or 13,333 microsteps per second. Fifty inches > per minute is 50/60=0.83333 inches per second, or 16,667 microsteps per > second. > > > The computer is a 1.0 GHz Pentium III with 386 Mb memory. I suspect > > it'll be OK at these speeds but would like someone to confirm this > > before I buy the drives. It is now running EMC without problem. > > I suspect that PC will handle a BASE_PERIOD of 20,000nS without a > problem. In theory you could get up to 25,000 steps per second with > that base period. In practice it will get a bit ratty at the top of > the range, but 16,000 or so should be fine. > > Regards, > > John Kasunich -- Hugh Currin Klamath Falls, OR USA ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
