On the IRC emc-dev channel there has been some discussion of the work being done, I believe by "micges", do incorporate gantry homing into EMC2 as a standard option. There is a branch of the source code that has some work already done in it but I haven't tried it out yet. I need to do the same thing in late February, which is getting near so I need to get on it soon.
Dave On 1/11/2010 1:16 PM, Jeff Ottesen wrote: > Arnold, > > I have not solved it but I think I know the direction to go. After digging > though the mailing list archive I found one thread that addressed homing of a > dual servo gantry. It looks like it will take some work in HAL - I have > included an excerpt of the thread below that sums it up fairly well. Other > than this, the info I have found has been for steppers or solutions that > handled gantry squaring outside of EMC2 by mechanical means or though the > servo drives themselves. I would be surpised if someone has not figured this > out given the number of large format machines running EMC2. I am 6 to 9 > months away from having a gantry to test with but I would be happy to work > with you on this if someone doesn't chime in with a solution. This is > something that should become a native element of homing in EMC2 as it is > fundamental to the operation of a dual drive gantry. > > > > Jeff > > > > Re: [Emc-users] syncing two motors to one axis > From: Jon Elson<el...@pi...> - 2009-04-01 17:28 > > Len Shelton wrote: > >> So let's say you have two drives, two motors, and two home switches on the >> same axis (gantry type machine). The problem with this arrangement is >> synchronization. The control needs to be aware of the two motors and needs >> to home both at the same time. While homing, we need to bring both motors >> towards the home switches together then independently home each motor when >> it reaches the home switch. >> >> How can this be done in EMC2? >> >> > We've gone over this a dozen times, at least. It would take about 10-15 > lines of HAL and several HAL components to perform the logic. > Basically, you make the two motors run at the same rate. As each motor > hits the home switch, it stops. When both have touched home, they move > together again to complete the precision home sequence to the encoder > index pulse. EMC2 already has features in HAL to handle tandem axes > like this, once homing is done. You feed the lettered axis (as in "X") > position to two numbered "joints" as in zero and one. So, the only > detail up in the air is how to do the homing. > > Jon > > > >> Message: 9 >> Date: Sun, 10 Jan 2010 11:32:40 +0100 >> From: Arnoldritercnc<arnoldriter...@gmail.com> >> Subject: Re: [Emc-users] Homing dual drive gantry >> To: "Enhanced Machine Controller (EMC)" >> <emc-users@lists.sourceforge.net> >> Message-ID:<4b49acc8.7050...@gmail.com> >> Content-Type: text/plain; charset=ISO-8859-1; format=flowed >> >> I have the same problem. Jeff, have you solved it? >> Any help will be very appreciated >> >> Thanks >> > > _________________________________________________________________ > Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. > http://clk.atdmt.com/GBL/go/196390709/direct/01/ > ------------------------------------------------------------------------------ > This SF.Net email is sponsored by the Verizon Developer Community > Take advantage of Verizon's best-in-class app development support > A streamlined, 14 day to market process makes app distribution fast and easy > Join now and get one step closer to millions of Verizon customers > http://p.sf.net/sfu/verizon-dev2dev > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
