What will be the total travel of this ballscrew? Is it static or does it travel as well?
On Thu, 19 Sep 2019 at 01:39, Curtis Dutton <curtd...@gmail.com> wrote: > my experiment is to use a force measuring device to proportionally control > torque output on a servo attached to a ball screw. > > as a thought experiment imagine a platform hoisted by said ball screw. as > you added weight to the platform the motor torque would increase to offset > the weight and keep it steady. or you could set the required force equal to > X kgs and with less than X kgs on the platform it would travel up > proportionally. the motor would increase torque to maintain the force > value. if more force than X the platform would travel down proportionally. > the motor would decrease torque to maintain the set force value. > > in effect not a position commanded but a force commanded linear actuator. > > is there some othere device that would be better for this type of force > measurement? in the 0 to about 500kg range. > > On Wed, Sep 18, 2019, 11:51 AM Chris Albertson <albertson.ch...@gmail.com> > wrote: > > > in any case, even with lower 16-bit precision, the most important part of > > the design is the analog portion that sits between the load cell and the > > A/D converter. > > > > > > > > On Wed, Sep 18, 2019 at 6:38 AM Curtis Dutton <curtd...@gmail.com> > wrote: > > > > > Chris thanks for the info. > > > > > > I'm not exactly certain at this point what precision I need. I'll be > > > determining that experimentally later. I will keep in mind what you > have > > > said, I'll deal with it after I get my hardware running. > > > > > > > > > On Tue, Sep 17, 2019 at 6:17 PM Chris Albertson < > > albertson.ch...@gmail.com > > > > > > > wrote: > > > > > > > If you want better than 16-bits and 1KHz then you also are going to > > need > > > a > > > > very good quality analog signal conditioning and instrumentation > > > amplifier. > > > > The analog circuit between the A/D converts and the load cell > really > > > does > > > > matter. You have to reject common-mode or the low bits will > just > > be > > > > filled with 60Hz noise. And you can not simply use a "brick wall" > > filter > > > > or you will not get the desired bandwidth through. (If you are > needing > > > to > > > > sample at 1K then you must care about 500Hz bandwidth. > > > > > > > > This matters a LOT more than which A/D chip you use. > > > > > > > > 22 bits is better than one part per million. Do you really need that? > > It > > > > will be hard to isolate all of the electrical and mechanical noise > > > > especially > > > > > > > > On Tue, Sep 17, 2019 at 2:26 PM Curtis Dutton <curtd...@gmail.com> > > > wrote: > > > > > > > > > I have a pet project I'm starting that will involve reading a load > > cell > > > > in > > > > > as near as real time as possible and using that input for servo > > > control. > > > > > > > > > > I plan on using mesa hardware to interface to the equipment. Does > > > anyone > > > > > know of a nice way to interface hotsmot2 to a load cell? > > > > > > > > > > I would like a fairly high resolution. 16 bit minimum, the higher > the > > > > > better up to 22 bit I suppose. As well as the ability to sample at > > the > > > > > servo thread rate of 1 Khz. > > > > > > > > > > > > > > > Thanks, > > > > > Curtis > > > > > > > > > > _______________________________________________ > > > > > Emc-users mailing list > > > > > Emc-users@lists.sourceforge.net > > > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > > > > > > > > > > > -- > > > > > > > > Chris Albertson > > > > Redondo Beach, California > > > > > > > > _______________________________________________ > > > > Emc-users mailing list > > > > Emc-users@lists.sourceforge.net > > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > > > > _______________________________________________ > > > Emc-users mailing list > > > Emc-users@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > > > -- > > > > Chris Albertson > > Redondo Beach, California > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
