On Mon, 12 Nov 2012, Tom Easterday wrote: > Date: Mon, 12 Nov 2012 19:13:15 -0500 > From: Tom Easterday <tom-...@bgp.nu> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Subject: Re: [Emc-users] Floating plasma torch - asking to share experience > > > On Nov 12, 2012, at 5:56 PM, Yishin Li wrote: > >> On Tue, Nov 13, 2012 at 1:06 AM, Marius Liebenberg >> <mar...@mastercut.co.za>wrote: >> >>> >>> I have seen many alternative solutions that all end up being scraped and >>> redone to floating head. >>> It is my opinion that the only good and maybe better alternative is the >>> capacitive sensing THC system. The simpler the solution the lesser the >>> troubles:) >>> >>> The plasma head we worked with is rigid type. We use the torque feedback >> of the Z-axis servo motor to decide if it is hitting the plate. We called >> it analog probing. It is useful for underwater plasma cutting. Here's the >> video: >> http://youtu.be/amnozqEhRYE > > > Very nice. This is a feature of Granite servo drives > (http://granitedevices.com/index.php?q=servo-drive-vsd-e). It is called > homing to a hard stop. We use it on our plasma machine to home the X and Y > axes which are driven by Granite VSD-E drives . We have it torque limit the > servo motors and slow the velocity until the axis runs into a door stop > (literally) that we placed at the end of travel. When the ferror reaches a > settable max it then backs up to the index pulse of the encoders. Very > accurate homing, no switches/wiring required. I never thought of using it to > do touch off for the torch, but why not? > > -Tom >
It should be noted that this should be possible with any torque mode servo and some HAL magic. Peter Wallace Mesa Electronics ------------------------------------------------------------------------------ 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
