Re: [Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-18 Thread Gene Heskett
On Thursday 18 August 2016 22:28:38 Martin Dobbins wrote: > >Agreed. And I have a saying when it appears that it will work, > > gopherit. I need to see if I can rewire this 1600 for parallel, > > which ought to speed it up considerably. But its 22mh per winding, > > so I don't expect miracles. >

Re: [Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-18 Thread Martin Dobbins
>Agreed. And I have a saying when it appears that it will work, gopherit. >I need to see if I can rewire this 1600 for parallel, which ought to >speed it up considerably. But its 22mh per winding, so I don't expect >miracles. >And then tell us how it works when you've lived with it for 2 weeks.

Re: [Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-18 Thread Gene Heskett
de back of it, and the motor on the front in a good stout nema 34 bracket. With a 1/1 belt drive, probably. We'll see, because the closer I can get the screw to the bed, the less swarf it will have to self wipe off. > > Martin > > > > > > > > _

Re: [Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-18 Thread Martin Dobbins
he "made in the USA" idea, the stepper solution is lot less $$. Martin From: Gene Heskett <ghesk...@shentel.net> Sent: Wednesday, August 17, 2016 10:37 PM To: emc-users@lists.sourceforge.net Subject: Re: [Emc-users] Clearpath Servo For Lat

Re: [Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-18 Thread Gene Heskett
On Thursday 18 August 2016 04:58:20 andy pugh wrote: > On 18 August 2016 at 04:37, Gene Heskett wrote: > > That flat line going to the left > > to zero speed, is the maximum steady torque over a longer period of > > time without overheating something. > > A typical

Re: [Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-18 Thread andy pugh
On 18 August 2016 at 04:37, Gene Heskett wrote: > That flat line going to the left > to zero speed, is the maximum steady torque over a longer period of time > without overheating something. A typical threading operation probably doesn't count as "steady state" except on

Re: [Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-17 Thread Gene Heskett
On Wednesday 17 August 2016 22:39:46 Martin Dobbins wrote: > That depends on 2 things, Martin. > 1. And likely the most important by far, is the coil inductance. > > A motor with only 2 millihenry's of inductance can achieve full coil > currents quick enough to have usable torque at 500 rpms.

Re: [Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-17 Thread Martin Dobbins
That depends on 2 things, Martin. 1. And likely the most important by far, is the coil inductance. A motor with only 2 millihenry's of inductance can achieve full coil currents quick enough to have usable torque at 500 rpms. The same motor frame, wound for the same starting torque but has a 15

Re: [Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-17 Thread Gene Heskett
On Wednesday 17 August 2016 17:54:46 Martin Dobbins wrote: > Gene wrote: > >Looking at the torque curves of the SDSK series, and the steady state > >available powers, for a spindle drive the steady state limit is the > >important one, and its much lower than its peak torque while moving > > to a

Re: [Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-17 Thread Martin Dobbins
>I would be surprised if a stepper of that size makes any torque at all >at 1500 rpm. >Is there a performance curve anywhere on t'internet? What was I typing??? I meant 500 rpm Martin I would be surprised if a stepper of that size makes any torque at all

Re: [Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-17 Thread andy pugh
On 17 August 2016 at 22:54, Martin Dobbins wrote: > It's very difficult (for me, at least) to compare a stepper motor to one of > these because the torque of a stepper is going to fall off rapidly with > speed. The stepper used is so huge, however, how much torque will it

Re: [Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-17 Thread Martin Dobbins
Gene wrote: >Looking at the torque curves of the SDSK series, and the steady state >available powers, for a spindle drive the steady state limit is the >important one, and its much lower than its peak torque while moving to a >fixed position. You have to get large and ex$pen$ive to get steady

Re: [Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-17 Thread andy pugh
On 17 August 2016 at 03:37, Martin Dobbins wrote: > > https://www.teknic.com/products/clearpath-brushless-dc-servo-motors/ > > The trouble is I know nothing about servo driven spindles, would they have > the same problem with poor torque at low revs that the Sherline DC motor

Re: [Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-17 Thread Gene Heskett
On Tuesday 16 August 2016 22:37:48 Martin Dobbins wrote: > Sherline lathe motors are not known for torque at very low speeds, > which is probably why Sherline sells this piece of kit for cnc > threading: > > http://sherline.com/product/6500-stepper-motor-mounting-kit/ > > This will work (very

[Emc-users] Clearpath Servo For Lathe Spindle?

2016-08-16 Thread Martin Dobbins
Sherline lathe motors are not known for torque at very low speeds, which is probably why Sherline sells this piece of kit for cnc threading: http://sherline.com/product/6500-stepper-motor-mounting-kit/ This will work (very slowly!) for cnc threading if a modest size Nema 23 stepper motor is