Hi Drew, The motor is a 3-phase Black Max 3HP inverter duty motor (Marathon Electric brand bought through Automation Direct). When I first installed it and used the basic settings on the VFD I could not run below about 300rpm or the current would spike and the VFD would trigger a shut down. After talking to A.D. tech support I configured it for a custom Volts/Hz curve (setting 2.00). I then had to change the various associated parameters (min output frequency, mid-point freq, etc). This allows the motor to spin down to about 50rpm surprisingly reliably but with much lower torque than at higher speeds. The lower torque is apparent if I try to stop the spindle with my hand at these low speeds - I can come close. It is just a compromise, we take light cuts at 200rpm and below and things are fine. I have been doing rigid tapping at 200rpm which can put a bit of a load on the spindle and I haven’t had a problem so for the time being we will stick to the GS2 VFD.
A.D. has pointed out to me several times that ideally if we need low speed torque and control we should be using a vector drive VFD. We might upgrade to a vector VFD at some point, or not, depending on if this becomes an issue for us. Even that isn’t a panacea though, ideally for complete control we’d use a servo motor for the spindle but that isn’t going to happen. If you care about why a vector drive helps this a good basic explanation of the difference that I found with a quick “google": http://www.eng-tips.com/faqs.cfm?fid=1062 BTW,If you are interested in the specific settings I used on the GS2 I can look on the VFD and send them along. -Tom > On Sep 13, 2015, at 10:40 AM, Drew Rogge <d...@dasrogges.com> wrote: > > Hi Tom, > > What spindle motor are you using that can reliably get down to 100 RPM? MY > 3phase with a GS2 VFD and barely handle 400 RPM. > > Thanks, > Drew > > > On 9/12/15 8:39 AM, Tom Easterday wrote: >> On Sep 12, 2015, at 10:51 AM, Gene Heskett <ghesk...@wdtv.com> wrote: >>> I see that video, very impressive. But what sort of a threading tool can >>> be driven at that high a side angle? None of the inserts I have, have >>> that sort of high angle side clearances. >> It is one of these, reversed in the turret (turning M3) with a 16ER A60 >> insert: http://www.shars.com/catalogsearch/result/?q=404-1979 >> -Tom >> ------------------------------------------------------------------------------ >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users > > -- > Drew Rogge > d...@dasrogges.com > > Phone: 8934OOO629OO4829631OOOOOOO > > > ------------------------------------------------------------------------------ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
