I just checked: http://www.automationtechnologiesinc.com/products-page/ac-servo-motors/the-ac-servo-driver-ac-servo-motor-400w-set
to replace my 12Nm steppers - the torque on this motor is 1.27 Nm (they rate is as high torque servos) - and is not near 12Nm, that my nema42 steppers now provide. Guess I need gearbox but this would introduce backlash - or there are some brushless servos with around 12Nm torque available? Any ideas who can provide 12Nm servos if they exist at all? On Wed, Jan 25, 2017 at 4:31 AM, Jon Elson <el...@pico-systems.com> wrote: > On 01/24/2017 03:54 PM, Greg Bernard wrote: > > Seeing the discussion of servo vs. stepper solutions come up once again > I wonder if anyone has had experience with these: http://www. > automationtechnologiesinc.com/products-page/nema34-closed- > loop-stepper-motor-system-hybrid-servo-kit/nema-34- > hybrid-servo-motor-kl34-8n-1000-rated-torque-1128-oz-in > > They are only step/dir but they are being used in both Tormach and > Shopbot machines which leads me to believe they are a cost-effective > middle-ground.Any thoughts? > > > Well, if you are going to go the whole closed-loop route, > why do it with a high pole-count stepper motor? > A 2-phase stepper needs 8 transistors, and you need high > driving frequencies to spin it fast. A 3-phase brushless > motor typically has 4-8 poles, so the frequencies are much > lower. (200 full step/rev steppers have 50 poles.) > And, the 3-phase drive only needs 6 transistors. The > stepper motor still has the resonance issue, even though the > drives are set up to not excite it, the resonance is still > there. The lower pole-count brushless motor moves it down > to a point where it is rarely a problem. > > So, I really don't see the advantage to the closed-loop > stepper. Automation technologies has quite affordable > brushless servo motors, too. > > Jon > > ------------------------------------------------------------ > ------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
