Hi this is a very interesting discussion. A couple of days ago i went to an exhibition<http://www.sps-italia.net/en/inside.asp>dedicated to the automation sector and I met an interesting small company <http://www.promax.it/index_en.html> that make CNC and motion controller with integrated PLC and they use a PC winzoz to interact with their controllers. One of the features that they are proud of is the gantry axes management . This is a video<http://www.youtube.com/watch?v=_zdtPvDA9K8&feature=youtu.be>that shows a pretty fast gantry machine in action (low resolution video, sorry). I don't know exactly what they are doing for the X axis homing sequence and for their gearing but seems to work really nicely.
regards bigalex On Fri, May 24, 2013 at 3:23 PM, Todd Zuercher <zuerc...@embarqmail.com>wrote: > The problem with all these gearboxes, sprokets chains and belts, is each > mechanical transmission joint you add adds lash to the system, not to > mention more things to wear out. Add this to the fact that large wood > routers like this need to move fast and I think he is much better off > sticking with what he has. > > I think that if the motors he has have indexes, I would think that some > setup homing to index would be best. After making sure the index points on > both motors are set so they are at the point where the gantry is square. > > Some experimentation will be reqired of course to see how best to > impliment this. With a bit of clevverness it might be able to work with > trivkins. > > The real trick might be tuning the servos. > > ----- Original Message ----- > From: "Gregg Eshelman" <g_ala...@yahoo.com> > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Sent: Friday, May 24, 2013 1:51:05 AM > Subject: Re: [Emc-users] gantry revisited > > Another way to mechanically connect the ends of any gantry. > > Fit a rack along each side. Mount a vertical shaft on each end with a gear > at the bottom to engage the racks. At the top ends of the shafts, mount > right angle gearboxes with a cross shaft connecting them. > > If the underside of the table is clear, with part of the gantry running > below it, then there are arrangements of cables and pulleys that make it > always stay square. > > The original Thermwood control system never had a problem with the gantry > trying to get crooked. Perhaps digging into its system could yield some > useful information? > > Is this retrofit a complete one, motors, drives and all? Or is it leaving > the motors and drives and replacing the computer? Just wondering if the > never-fail keep it square system had nothing to do with the controlling > system but was built into the drive system? If you've replaced *everything* > electronic and electrical on the machine, then you've removed the 'magic' > system that kept the gantry square. > > > ------------------------------------------------------------------------------ > Try New Relic Now & We'll Send You this Cool Shirt > New Relic is the only SaaS-based application performance monitoring service > that delivers powerful full stack analytics. Optimize and monitor your > browser, app, & servers with just a few lines of code. Try New Relic > and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_may > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > > ------------------------------------------------------------------------------ > Try New Relic Now & We'll Send You this Cool Shirt > New Relic is the only SaaS-based application performance monitoring service > that delivers powerful full stack analytics. Optimize and monitor your > browser, app, & servers with just a few lines of code. Try New Relic > and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_may > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, & servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_may _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
