Charles, I use LCNC on gantry routers and plasma machines with dual steppers on the X axis all the time. I simply slave the second motor in the HAL file with an inverted DIR signal. I have my motors driving on a Rack and Pinion setup always and I have a spring loaded motor plate to apply constant tension to the pinion. If need be one can just release the motors and place the gantry in a neutral position before homing. I found that if the machine is setup to be NOT close to it maximum performance, it will never give any problems. If the gantry has racked, I simply run it into the stops slowly and the slippage will correct the skew.
I have never had the need to run a router in joint mode so I dont have the problems that come with that. For my sake please explain the use of joint mode with the router. On 2014-02-18 01:19, Charles Steinkuehler wrote: > On 2/17/2014 4:47 PM, Steve Blackmore wrote: >> On Sun, 16 Feb 2014 16:51:06 -0600, you wrote: >> >>> On 2/16/2014 4:03 PM, Steve Blackmore wrote: >>>> On Sun, 16 Feb 2014 14:11:13 -0600, you wrote: >>>> >>>>> With the recent release and general popularity of the ShapeOko V2 >>>>> desktop mini-mill, I have several folks who are trying to use LinuxCNC >>>>> running on the BeagleBone as a control. If you are unfamiliar with this >>>>> machine, here's a link: >>>>> >>>>> https://www.inventables.com/technologies/desktop-cnc-mill-kit-shapeoko-2 >>>> Cant help with the best way to run that with LinuxCNC, but I'd be >>>> tempted to remove one stepper and run a cross shaft driving both belts >>>> with possibly a bigger stepper motor. >>> Sorry, but I don't consider changing the machine to fit the tool to be >>> an acceptable solution. >> Then your stuck with a known problematic design. I wish I had a pound >> for each complaint/query/moan I've seen and heard about twin steppers on >> a gantry machine. >> >> Other fixes include servos or closed loop steppers but keeping both >> sides in synch with software without any feedback is nigh on impossible. > Steppers are not the problem, the issues I mentioned apply equally to > machines with servos and encoder feedback. > > I'm asking for the suggested best way to configure LinuxCNC for > controlling a gantry system, that presents the user with the least > opportunity to "shoot themselves in the foot". For instance, how do you > avoid racking the gantry when jogging in joint mode? Do you have a > servo gantry config that avoids or minimizes this possibility you could > point me to? > > I know folks are controlling gantry systems with LinuxCNC, I'm wanting > to know how, and what are the pros and cons of each setup. > > > > ------------------------------------------------------------------------------ > Managing the Performance of Cloud-Based Applications > Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. > Read the Whitepaper. > http://pubads.g.doubleclick.net/gampad/clk?id=121054471&iu=/4140/ostg.clktrk > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- Regards /Groete Marius D. Liebenberg +27 82 698 3251 +27 12 743 6064 ------------------------------------------------------------------------------ Managing the Performance of Cloud-Based Applications Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. Read the Whitepaper. http://pubads.g.doubleclick.net/gampad/clk?id=121054471&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
