2009/12/9 Martin Pinkston <[email protected]>: > Stepper motors use step, direction and enable. Chop drives use pulse, pulse, > pulse, pulse. That 4 pulse signal is fed into the drive cards.
(Skip through this until you get to something you don't know...) Stepper motors generally have 2 sets of windings, and are made to rotate by running through a repeating pattern of excitation. I was going to tabulate some examples of unipolar and bipolar excitation pattern tables, but realised I don't know them. :-) There is a lot of basic info here though http://www.solarbotics.net/library/pdflib/pdf/motorbas.pdf Generally we use stepper drivers to work out the step sequence, we pass across step and direction signals, and the driver card converts that to individual winding excitations. It is possible that your original setup oflloaded the step table sequencing to the PC software. However, EMC can also drive the phases directly. In fact you could drive a very, very, small stepper directly from the parallel port. More typically you would amplify the mA parallel port signals to several A of drive current with external hardware, which is why stepper drives are sometimes called amplifiers. If you look in the HAL configuration that Stepconf has produced you will see that it has created a bunch of Type = 0 stepgen modules. If you look at http://linuxcnc.org/docs/html/man/man9/stepgen.9.html you will see that type 0 is only one of many possible configurations, one of which might suit your drives. The tricky bit is working out what your drives need. Frankly, though, things have moved on in the last 20 years. You could probably replace your driver cards and get significantly better performance and something with documentation and spec sheets. Even the cheap quad driver boards from eBay would be a useful upgrade. Two possibilities, cheap and cheerful: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250544095826 and more expensive but very easy: http://www.geckodrive.com/product.aspx?c=3&i=14469 -- atp ------------------------------------------------------------------------------ Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
