Good thinking Ken. Till built a dual drive sort of thing several years ago to test some special kinematics.
http://www.audiflitzer.de/mixer.html HTH Rayh On Fri, 2008-05-23 at 14:57 -0400, Kenneth Lerman wrote: > A simple solution is to use a dual drive. > > Use a course mechanism with long travel for course positioning and a > fine mechanism with limited travel for fine positioning. The fine > mechanism has a large mechanical advantage and can use a smaller motor > and driver. Of course, some sort of clutch mechanism could be used to > allow switching between the course and fine speeds. > > You haven't answered the question of what type of mechanism you are > planning to use to provide smooth linear and rotary motions at this slow > speed. > > Ken > > [EMAIL PROTECTED] wrote: > > travel at feed 0.001 will be geometry of 1 inch end mill, with length of > > end mill 4 inch. 0.001 /min it is cutting feed only. rapid to new position > > will be much faster. > > > > > >> It is my understanding that in a grinding machine: > >> > >> 1 -- Cutting forces are low. > >> > >> 2 -- Backlash is generally not important. > >> > >> 3 -- Smoothness of motion is very important. > >> > >> I would suggest that before you worry about how to drive the components > >> in slow motion, you should tell us how you plan to drive the components > >> smoothly. > >> > >> What are you going to use for linear (for the linear axis) bearings and > >> what will you use for rotary bearings? Stiction can be a major issue. > >> Air bearings come to mind as a possible solution. > >> > >> Regarding the feed rate of .001 inch per minute and the distance of 12 > >> inches. Am I correct in assuming that you would not be traversing that > >> length at that feed? If that is true, what is the actual distance that > >> has to be traveled at that rate for any given "pass. A simple mechanism > >> to provide very high reduction ratios is the differential screw. It > >> does, however, have a limited range of motion. > >> > >> It sounds like an interesting project. Do you have any sketches showing > >> the general layout? > >> > >> Ken > >> > >> [EMAIL PROTECTED] wrote: > >>> look design of harmonic derive. it is compact and small. you do not want > >>> to have huge gear reduction box on the machines. space are limited too. > >>> > >>>> Is there some reason why simple worm and wheel drives won't work here - > >>>> even two or three stages with backlash adjusted out? > >>>> > >>>> Ian > >>>> -------------------- > >>>> Ian W. Wright > >>>> Sheffield UK > >>>> > >>>> > >>>> ------------------------------------------------------------------------- > >>>> This SF.net email is sponsored by: Microsoft > >>>> Defy all challenges. Microsoft(R) Visual Studio 2008. > >>>> http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > >>>> _______________________________________________ > >>>> Emc-users mailing list > >>>> Emc-users@lists.sourceforge.net > >>>> https://lists.sourceforge.net/lists/listinfo/emc-users > >>>> > >>> > >>> > >>> ------------------------------------------------------------------------- > >>> This SF.net email is sponsored by: Microsoft > >>> Defy all challenges. Microsoft(R) Visual Studio 2008. > >>> http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > >>> _______________________________________________ > >>> Emc-users mailing list > >>> Emc-users@lists.sourceforge.net > >>> https://lists.sourceforge.net/lists/listinfo/emc-users > >> -- > >> Kenneth Lerman > >> Mark Kenny Products Company, LLC > >> 55 Main Street > >> Newtown, CT 06470 > >> 888-ISO-SEVO > >> 203-426-7166 > >> > >> ------------------------------------------------------------------------- > >> This SF.net email is sponsored by: Microsoft > >> Defy all challenges. Microsoft(R) Visual Studio 2008. > >> http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > >> _______________________________________________ > >> Emc-users mailing list > >> Emc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > > > > > > > > ------------------------------------------------------------------------- > > This SF.net email is sponsored by: Microsoft > > Defy all challenges. Microsoft(R) Visual Studio 2008. > > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > -- > Kenneth Lerman > Mark Kenny Products Company, LLC > 55 Main Street > Newtown, CT 06470 > 888-ISO-SEVO > 203-426-7166 > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2008. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
