I think it would work fine, you can set the torque and velocity quite low. I think I could touch off on cardboard if I had to :-) -Tom
On Nov 12, 2012, at 8:14 PM, John Thornton wrote: > But not practical for touch off on thin material... > > > On 11/12/2012 6:30 PM, Peter C. Wallace wrote: >> 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 > > > ------------------------------------------------------------------------------ > 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