On Sunday, December 25, 2011 12:08:02 PM kqt4a...@gmail.com did opine: > On Sun, 25 Dec 2011, gene heskett wrote: > > On Sunday, December 25, 2011 10:11:27 AM kqt4a...@gmail.com did opine: > >> On Sat, 24 Dec 2011, gene heskett wrote: > >>> On Saturday, December 24, 2011 03:43:00 PM kqt4a...@gmail.com did > > > > opine: > >>>> On Sat, 24 Dec 2011, gene heskett wrote: > >>>>> On Saturday, December 24, 2011 02:26:16 PM kqt4a...@gmail.com did > >>> > >>> opine: > >>>>>> On Sat, 24 Dec 2011, gene heskett wrote: > >>>>>>> On Saturday, December 24, 2011 01:48:17 PM kqt4a...@gmail.com > >>>>>>> did > >>>>> > >>>>> opine: > >>>>>>>> Probotix equipment > >>>>>>>> 40VDC 10Amp Linear Power Supply > >>>>>>>> PBX-RF RF Isolated CNC Breakout Board > >>>>>>>> 3 - Uni-polar Stepper Motor Chopper Drivers > >>>>>>> > >>>>>>> Specs on this driver board please? > >>>>>> > >>>>>> http://www.probotix.com/manuals/ProboStepVX.pdf > >>>>>> > >>>>>>>> 3 - 280 OzIn 8-Wire Stepper Motor > >>>>>>>> > >>>>>>>> I have run this setup for over a year with no problems, so I > >>>>>>>> thought I would create one I have a used Pacific Scientific > >>>>>>>> Powermax II stepper model P21NRXA-LNF-NS-00 I could not send > >>>>>>>> the datasheet for the motor so I sent the link to it > >>>>>>>> http://www.electromate.com/db_support/downloads/Nema23PowermaxI > >>>>>>>> I. pd f > >>>>>>> > >>>>>>> This data sheet shows 2 things, one that it does run hot, very > >>>>>>> hot. 130C in a 40C environment. To me that is too hot, but they > >>>>>>> know their varnish better than I do. Any other comments I'll > >>>>>>> wait for the driver specs to make. > >>>>>>> > >>>>>>>> I > >>>>>>>> added a 4th Uni-polar Stepper Motor Chopper Drivers > >>>>>>>> Wired motor and driver and they actually work > >>>>>>>> > >>>>>>>> Issue 1 > >>>>>>>> The motor gets VERY hot > >>>>>>>> I have run the other motors for a couple of hours and they got > >>>>>>>> hot but the SI motor will burn your fingers after about 15 > >>>>>>>> minutes The manual for the Uni-polar Stepper Motor Chopper > >>>>>>>> Drivers says to set the current limiter to .145 * > >>>>>>>> target_current, 2.8 amps = .406 I reduced it to .38 and it > >>>>>>>> still gets too hot > >>>>>>>> > >>>>>>>> Issue 2 > >>>>>>>> The motor is slow > >>>>>>>> The label says max 1500 rpm but I can only get a fraction of > >>>>>>>> that I use EMC 2.4.6 > >>>>>>>> The driver is set to 1/8 stepping > >>>>>>>> > >>>>>>>> [AXIS_3] > >>>>>>>> TYPE = ANGULAR > >>>>>>>> HOME = 0.0 > >>>>>>>> MAX_VELOCITY = 360 > >>>>>>>> MAX_ACCELERATION = 5000.0 > >>>>>>>> STEPGEN_MAXACCEL = 6250.0 > >>>>>>>> SCALE = 4.44444444444 > >>>>>>>> FERROR = 1 > >>>>>>>> MIN_FERROR = .25 > >>>>>>>> MIN_LIMIT = -9999.0 > >>>>>>>> MAX_LIMIT = 9999.0 > >>>>>>>> HOME_OFFSET = 0.0 > >>>>> > >>>>> Off topic, from this I assume its running a rotary table? > >>>> > >>>> Probably but now it is just a motor sitting on the bench > >>>> > >>>>> If that table has the usual 72 or 90 gear down, those settings are > >>>>> a bit off. > >>>> > >>>> If I do gear this thing down I will fall asleep waiting for it to > >>>> turn > >>>> > >>>>>> From one of my ini files that included a 425oz motor on a 4" > >>>>>> Grizzly > >>>>> > >>>>> table, direct drive to the worm: > >>>>> [AXIS_3] > >>>>> TYPE = ANGULAR > >>>>> HOME = 0.0 > >>>>> MAX_VELOCITY = 81.8965517241 > >>>>> MAX_ACCELERATION = 1200.0 > >>>>> STEPGEN_MAXACCEL = 1500.0 > >>>>> SCALE = 200.0 > >>>>> FERROR = 1 > >>>>> MIN_FERROR = .25 > >>>>> MIN_LIMIT = -9999.0 > >>>>> MAX_LIMIT = 9999.0 > >>>>> HOME_OFFSET = 0.0 > >>>> > >>>> Your setting do get me more rpms but g0 a180 results in many > >>>> revolutions In the not too distant future I hope to be driving a > >>>> rotary table with this So how do I adjust these setting for > >>>> whatever my final reduction will be > >>> > >>> That scale is telling emc how many steps it has to move the motor to > >>> make one units worth of motion. For a table I think its 1 degree > >>> but I can be corrected since it could be a radian too. > >>> What I meant by the geardown, is how many turns of the dial handle > >>> shaft on the table does it take to make one full 360 degree turn, > >>> and depending on the table it could be 90 or 72 full turns of the > >>> worm shaft to make one full turn of the table. > >> > >> I am still quite confused > >> My ignorance is killing me > >> > >> [EMCMOT] > >> EMCMOT = motmod > >> COMM_TIMEOUT = 1.0 > >> COMM_WAIT = 0.010 > >> BASE_PERIOD = 28000 > >> SERVO_PERIOD = 1000000 > >> > >> [TRAJ] > >> AXES = 4 > >> COORDINATES = X Y Z A > >> MAX_ANGULAR_VELOCITY = 8035.71 > >> DEFAULT_ANGULAR_VELOCITY = 60.00 > >> LINEAR_UNITS = inch > >> ANGULAR_UNITS = degree > >> CYCLE_TIME = 0.010 > >> DEFAULT_VELOCITY = 0.33 > >> MAX_LINEAR_VELOCITY = 3.30 > >> > >> [AXIS_3] > >> TYPE = ANGULAR > >> HOME = 0.0 > >> MAX_VELOCITY = 7633.92857143 > > > > Laying on the table & measuring the shaft rotation, this wouldn't be > > very fast. a fraction over 21 rpm, nominally 3 seconds per rev. Not > > rps, rpm. But when 'scaled' to drive a table, its way faster than any > > stepper could be driven to at my usual psu voltage of 28 volts. A > > big Gecko running on 80 volts, maybe. > > MAX_VELOCITY = 7633.92857143 (degrees per second), right????? > (7633.92857143 / 360) * 60 = 1272.32142857166666666660 rpm > Which is what I see whem I test with stepconf > But locks up in Axis
Locks up the computer, or the motor? If it's the computer, what is the base_period setting in your .ini file? It's stated in nanoseconds. If it is the motor that locks, likely MAXVEL is too high, and is not being restricted enough by the next two lines. These motors are stepper, yes, but they cannot go from stopped to 300 rpm in a single step, they must be accelerated and decelerated at a profile that when the mass of the load is added to the shaft, they can still accelerate/decelerate at without losing a step. If a step is lost, they will usually stall in place, probably just vibrating a bit till you hit the stop/esc. so the greater the mass the load has, the lower these next two values need to be to keep from asking the motor to do something it can't. Secondarily, resonance in the form of rotational vibrations can at certain speeds, cause a loss of effective power and locking, which is the reason for the damper assemblies seen on the rear of many of these motors. Mine, that you can see in the emc link on my web page in the sig, consists of a long spool, with alternating sheets of dead rubber whose center has to be stretched to get them onto the spool shaft, and large 'fender washers' which act as lossy flywheels, which in turn allows those motors to get through the resonance frequency, doubling (or more) the effective working speed. I went from about 8 ipm to nearly 27 ipm by building and installing the ones you can see on that page. I currently limit at 22.5 ipm because my table binds the ways when its way out to one side. Those washers can be turned by hand as the whole stack is a bit loose, intended. However, this is fine tuning it once you get it moving, so do that first... Andy had a question that might be relevant I think. > See attached > > >> MAX_ACCELERATION = 50000.0 > >> STEPGEN_MAXACCEL = 62500.0 > > > > These 2 are, IMO, way too high. > > > >> SCALE = 4.44444444444 > > > > Is this the 'scale' that turns the motor 1 degree? > > Yes??? > From integrator manual > > SCALE = 4000 ( HAL ) Speciï¬پes the number of pulses that corresponds to > a move of one machine unit as set in the [TRAJ] section. For stepper > systems, this is the number of step pulses issued per machine unit. For > a linear axis one machine unit will be equal to the setting of > LINEAR_UNITS. For an angular axis one unit is equal to the setting in > ANGULAR_UNITS. > > With 1/8 stepping 4.444... pulses per degree > Agreed. :) [...] Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> "You have been in Afghanistan, I perceive." -- Sir Arthur Conan Doyle, "A Study in Scarlet" ------------------------------------------------------------------------------ Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
