Here are some new Nema 48's from Baldor. http://www.electricmotorwholesale.com/BALDOR-MOTORS-3PH-DP.html
Here is Siemens standard motor catalog - if you look at page 2/10 you can get an idea of the IEC/Metric frame sizes and relative power outputs. http://www.motology.co.th/download/motors/%282%29%20Standard%20Motor%20catalog.pdf On Ebay do a search for "48 frame motor 3 phase". I got almost 100 hits from that search. Maybe 1/3 of them were worthwhile items. I'm not sure how much HP you are looking for. Your other option is to pickup a used brush DC motor and match that up with a DC drive. A lot of them go pretty cheap because most people are trying to get away from brush maintenance. But DC motors can have 100% torque at very low speeds which is usually not possible with a VFD driven AC motor. Most low HP DC motors tend to be skinny. :-) Dave On 6/14/2015 12:14 PM, Gene Heskett wrote: > On Sunday 14 June 2015 10:54:57 Dave Cole wrote: >> Gene, >> >> Try looking for a Nema 48 AC motor. They are almost an inch smaller >> in diameter. > That makes perfect sense. But no search hits until I drop it to Nema 42. > >> Also, there are some metric frame motors that are common in Europe >> that are also smaller in diameter than a Nema 56. >> >> http://kurz.com/wp-content/uploads/2014/09/Baldor-NEMA-Frame-Chart.pdf >> >> http://www.engineeringtoolbox.com/nema-electrical-motor-frame-dimensio >> ns-d_1504.html >> >> Dave >> > I think one of the things that is confusing me is when you or I think 3 > phase, we are thinking of a hard armature that is in fact a p.m. So > while it may have a phase lag due to loading, it is in fact synchronous. > Such a motor can be driven at stump pulling speeds with full torque > available just by dropping the drive frequency, and they will do it > without excessive heating if the invertor is current regulated. Fading > only when the rpms doesn't generate a cooling air flow. > > But for the average guy peddling what he found on ebay, he has no clue > how to tell us that THIS motor is in fact an induction motor, and the > output rpms MUST lag the frequency because that is what generates the > currents in the armature that make it run. > > So how do we discern the induction motor,totally unsuitable for vfd drive > except near is design rpms, from the synchronous motor at home on a vfd > drive? > > Example: > Doing a search for a 3 phase motor, the complete first 50 hits are all > induction, none claim to turn as synchronous speeds. All "slip" some as > much as 75 rpm from 1800. 1800 or 3600 on 60hz would indicate one we > might be able to use. > >> On 6/14/2015 10:16 AM, Gene Heskett wrote: >>> On Sunday 14 June 2015 05:06:22 andy pugh wrote: >>>> On 14 June 2015 at 02:38, Gene Heskett <[email protected]> wrote: >>>>> It does look good, but where can I get an adaptor to mount that >>>>> 56C frame on the GO704? Or is that my first project, making one? >>>>> ;-) >>>> What is the existing motor mount? >>> About an inch smaller OD than a 56C. >>> >>>> I adapted my Mini-Mill to a standard 3-phase motor: >>>> https://picasaweb.google.com/lh/photo/Dk3wsS9o7XJ-N2kfUnESDtMTjNZET >>>> Ymy PJy0liipFm0?feat=directlink >>>> >>>>> At $116 + ship, looks good also. Needs a modbus circuit from lcnc. >>>>> Who has that hardware? >>>> Just because you can use Modbus it doesn't mean that you must use >>>> Modbus. Those VFDs all accept analogue voltage, potentiometer and >>>> current-loop too. >>> That greatly simplifies that, 5i25 pwm out driving a SpinX1 which I >>> have. >>> >>> Cheers, Gene Heskett >> --- >> This email has been checked for viruses by Avast antivirus software. >> https://www.avast.com/antivirus >> >> >> ---------------------------------------------------------------------- >> -------- _______________________________________________ >> Emc-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-users > Cheers, Gene Heskett --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
