Charles, I think you know my vote.
1) Never assume the user is anything other than a complete amateur. We are putting tons of these machines in schools now. 2) I believe this is the right way to do this. If the BBB cannot do this, we will be forced to add a secondary microcontroller in the pulse stream to apply the logic that we need to do this. Seems kinda silly since the software could do it. If I only knew more about LCNC programming, it already would. This is the one thing that's preventing us from moving all of our machines to the BBB immediately. 3) I am really surprised that this works at all without blowing the drivers. You cannot guarantee that both motors are identical. >Len On 2/16/2014 7:47 PM, Dave Cole wrote: > > > If you can control the current settings on the stepper drives, lower the > torque settings and drive the gantry axes steppers > together into the hard stops, set the axes to home, then reset the > torque settings to normal. > > Dave > > On 2/16/2014 3:11 PM, Charles Steinkuehler 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 >> >> Invariably, one of the first questions I get is how to setup a >> configuration to deal with the gantry setup of the ShapeOko. I know of >> at least three different ways to control a gantry system with LinuxCNC, >> each with it's own pros and cons: >> >> 1) Use gantrykins, and hope users are intelligent enough not to rack the >> gantry when moving around in joint mode. >> >> 2) Use trivkins and setup HAL to turn one axis into two by craftily >> combining the commanded motion with the homing switch states. This is >> easiest if HAL is doing software stepgen (just mask the step pulses in >> the base thread), but I'm pretty confident I can make this work pushing >> the logic in front of the PRU drive step/dir component (as a bonus, this >> setup would also work with Mesa hm2 cards and other hardware based >> controllers). >> >> 3) Ignore the gantry complexity, and just drive both servo motors from >> the same stepper driver. This works _OK_ for the Z axis on a 3D >> printer, but probably isn't a good idea for something that is actually >> making chips. >> >> Questions: >> >> Did I miss any significant options for controlling a gantry style machine? >> >> Which option would be recommended for novice users new to the LinuxCNC >> and CNC world? >> >> I'm thinking the "Magic HAL Wye / Y Cable" that splits one joint into >> two is probably the simplest for most folks to deal with, but am open to >> suggestions. >> >> >> >> ------------------------------------------------------------------------------ >> Android apps run on BlackBerry 10 >> Introducing the new BlackBerry 10.2.1 Runtime for Android apps. >> Now with support for Jelly Bean, Bluetooth, Mapview and more. >> Get your Android app in front of a whole new audience. Start now. >> http://pubads.g.doubleclick.net/gampad/clk?id=124407151&iu=/4140/ostg.clktrk >> >> >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------------------------ > Android apps run on BlackBerry 10 > Introducing the new BlackBerry 10.2.1 Runtime for Android apps. > Now with support for Jelly Bean, Bluetooth, Mapview and more. > Get your Android app in front of a whole new audience. Start now. > http://pubads.g.doubleclick.net/gampad/clk?id=124407151&iu=/4140/ostg.clktrk > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Len Shelton Applications Engineer PROBOTIX 8800-B N. Industrial Rd. Peoria, IL. 61615 Email: l...@probotix.com Phone: (309) 691-2643 ------------------------------------------------------------------------------ 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
