What resolution of encoders have should I use, my first thought is as high as possible, is my logic wrong?
Andy Dave Engvall wrote: > > On May 15, 2007, at 3:13 PM, Andy Holcomb wrote: > >> Does anyone know the price an encoder that would work on this machine >> with emc and not made out of gold? > Of course, the first thing to do is make certain that you have > resolvers and therefore need to to something about this. > http://web2.automationdirect.com/static/specs/encoderld.pdf > These encoders are $80 + change and seem to work OK. They are not IP64 > so you may want to isolate them from the > environment a bit. > > US Digital also makes encoders that are not too spendy. > > Dave > >> >> Will the geckos run these motors? and are they good with emc? I am >> trying to get an idea of the cost to retro fit it. >> >> Andy >> >> Ray Henry wrote: >>> I started servicing CNC machines a couple years before this machine was >>> made. I never saw a stepper used for axis positioning until much later. >>> They were used to pace the tape through a tape reader during that >>> time. >>> >>> Let's assume that you've got servos. Next issue is the nature of the >>> position feedback. Many of the machines from the the seventies and >>> eighties used resolvers rather than pulse coders. A resolver does not >>> produce pulses that can be counted. >>> >>> A resolver uses ac rather than dc power. They take two ac signals, sine >>> and cosine to each other and return the rotor position as a phase >>> shifted signal. My experience suggests that one way you can tell a >>> resolver is that the six wires from it were twisted in pairs. If it was >>> placed in a can with a plug, good luck figuring it out. (This is where a >>> wiring diagram would be a real help) >>> >>> Assuming resolver feedback there are a couple things you can do. The >>> first is get a resolver to quadrature converter box. With such a box >>> you get the signal generator to power the resolver and a fixed number of >>> pulses per rotation of it. You could also replace the resolver with an >>> encoder. This is what MattS and I did with a Hardinge lathe. He had a >>> little spindle built that matched the size and arrangement of the >>> Harosun(sp) resolver and mounted a shaft encoder on top of it. >>> >>> Okay. Let's say now that you've got quadrature feedback of axis and >>> spindle position. Now you need a way to get those signals into the PC >>> running EMC2. Several board makers have devices that can do this. EMC >>> has HAL driver modules that can read these. In alphabetical order, some >>> of these include. Mesa, Pico, Pluto, STG, Vigilant, Vital. You'll find >>> links to these companies at www.linuxcnc.org. >>> >>> And lastly you will have to produce a velocity signal of the sort >>> expected by the motor's drive amplifier. In that age most of the drives >>> used an analog signal that varied between -10v and +10 volt. Again the >>> board makers will usually have that ability as well. >>> >>> HTH >>> >>> Rayh >>> >>> >>> On Tue, 2007-05-15 at 15:19 -0500, Andy Holcomb wrote: >>> >>>> I am just looking at it, I wanted to know what the task of changing it >>>> to emc looked like. It does have the crt. I don't think he has the >>>> books. If this is a servo an encoder machine what equipment will be >>>> required to talk to it? >>>> >>>> Andy >>>> >>>> >>>> >>>> >>>> >>>> Ed wrote: >>>> >>>>> Andy Holcomb wrote: >>>>> >>>>> >>>>>> Has any buddy messed with any old Pratt and Whitney CNC Lathes? This >>>>>> one has a fujisu fanuc controller, it is a turn mate 1981 model. >>>>>> >>>>>> Does it run steppers of servos? >>>>>> >>>>>> If it is Servos what would it take to get emc running it? >>>>>> >>>>>> Andy >>>>>> >>>>>> ------------------------------------------------------------------------- >>>>>> This SF.net email is sponsored by DB2 Express >>>>>> Download DB2 Express C - the FREE version of DB2 express and take >>>>>> control of your XML. No limits. Just data. Click to get it now. >>>>>> http://sourceforge.net/powerbar/db2/ >>>>>> _______________________________________________ >>>>>> Emc-users mailing list >>>>>> Emc-users@lists.sourceforge.net >>>>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>>>> >>>>>> >>>>>> >>>>>> >>>>> Does this machine have a CRT or is it a single line display? I have one >>>>> that was built in 82 that has a CRT and uses servo motors with encoders, >>>>> I bought it to do a retro with EMC but it turned out to have been >>>>> "disabled" so the machine would be replaced with a new one. Do you have >>>>> the books with it? They have good schematics. Ed. >>>>> >>>>> ------------------------------------------------------------------------- >>>>> This SF.net email is sponsored by DB2 Express >>>>> Download DB2 Express C - the FREE version of DB2 express and take >>>>> control of your XML. No limits. Just data. Click to get it now. >>>>> http://sourceforge.net/powerbar/db2/ >>>>> _______________________________________________ >>>>> Emc-users mailing list >>>>> Emc-users@lists.sourceforge.net >>>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>>> >>>>> >>>>> >>>> ------------------------------------------------------------------------- >>>> This SF.net email is sponsored by DB2 Express >>>> Download DB2 Express C - the FREE version of DB2 express and take >>>> control of your XML. No limits. Just data. Click to get it now. >>>> http://sourceforge.net/powerbar/db2/ >>>> _______________________________________________ >>>> Emc-users mailing list >>>> Emc-users@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>> >>>> >>> ------------------------------------------------------------------------- >>> This SF.net email is sponsored by DB2 Express >>> Download DB2 Express C - the FREE version of DB2 express and take >>> control of your XML. No limits. Just data. Click to get it now. >>> http://sourceforge.net/powerbar/db2/ >>> _______________________________________________ >>> Emc-users mailing list >>> Emc-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/emc-users >>> >>> >> ------------------------------------------------------------------------- >> This SF.net email is sponsored by DB2 Express >> Download DB2 Express C - the FREE version of DB2 express and take >> control of your XML. No limits. Just data. Click to get it now. >> http://sourceforge.net/powerbar/db2/_______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net <mailto:Emc-users@lists.sourceforge.net> >> https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------------------ > > ------------------------------------------------------------------------- > This SF.net email is sponsored by DB2 Express > Download DB2 Express C - the FREE version of DB2 express and take > control of your XML. No limits. Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > ------------------------------------------------------------------------ > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
