There are stepper drivers that can extract feedback for detecting missing steps, but they require parameters be set to match the particular motor. One such device is the TMC246 from www.trinamic.com See:
http://www.trinamic.com/index.php?option=com_content&view=article&id=171&Ite mid=302 I looked at basing a product around this concept but decided that it was not practical to offer a general purpose driver with this function because it would be too hard to support unless you sold matching motors. Steve Stallings > -----Original Message----- > From: craig [mailto:cr...@facework.com] > Sent: Sunday, November 25, 2012 10:58 PM > To: emc-users@lists.sourceforge.net > Subject: [Emc-users] Stepper response > > The post: > > " /Re: [Emc-users] Spindle position, direction and Index with > only one > channel.// > // > //On 11/24/2012 5:01 PM, James Boulton wrote:// > / > > /Has anyone on list used a stepper as an encoder like this: > > > > http://home.clear.net.nz/pages/joecolquitt/stepper_as_encoder.html > > > > James// / " > got me reconsidering something I thought about some time ago and laid > aside because I have the neither the expertise nor the time to > investigate it. > > What useful information can be extracted from sensing stepper voltage > and current responses? > > Are there useful differences in the waveforms for missing > steps? nearly > missing steps? > > If there are, the detection of such events could be quite useful. For > many application 1 or 2 missing steps before stopping might be quite > acceptable. > > If one could detect such things, one might be able to work > much faster > in materials with highly variable hardness/ resistance (e.g. knots in > wood). or be able to stop replace a dull tool and finish the > job still > within acceptable tolerances. > > Inexpensive sensors and microprocessors might be able to > implement the > needed feature extraction and pattern recognition at > relatively low cost. > > Has anybody seriously looked at this? > > Does anyone know of good models of stepper physics that could > be used to > guess what to look for? > > Craig > > > > > > > > > > > > > > > -------------------------------------------------------------- > ---------------- > Monitor your physical, virtual and cloud infrastructure from a single > web console. Get in-depth insight into apps, servers, > databases, vmware, > SAP, cloud infrastructure, etc. Download 30-day Free Trial. > Pricing starts from $795 for 25 servers or applications! > http://p.sf.net/sfu/zoho_dev2dev_nov > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
