Re: [Emc-users] Spindle rps and index

2021-03-18 Thread dave engvall
My Mazak V5 had a coarse helix cam which oriented the spindle. The one at Galesburg used something closer to  an  inductive sensor to sense index.. I think that got swapped out for an encoder. Once it picked up the index it then rotated n counts to index the spindle for tool change.  If memory

Re: [Emc-users] Spindle rps and index

2021-03-18 Thread John Dammeyer
> -Original Message- > From: Jon Elson [mailto:el...@pico-systems.com] > > Interesting topic. > > > > I take it then that you can't actually move the spindle to the index > > position unless you have some sort of control beyond velocity? > > > > I'm currently using PWM on mine but once

Re: [Emc-users] Spindle rps and index

2021-03-18 Thread Jon Elson
On 03/18/2021 08:43 PM, John Dammeyer wrote: -Original Message- From: Jon Elson [mailto:el...@pico-systems.com] Sent: March-18-21 6:22 PM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] Spindle rps and index On 03/18/2021 05:18 PM, Nicklas SB Karlsson wrote: Need to

Re: [Emc-users] OT: Driving tiny steppers

2021-03-18 Thread Gene Heskett
On Thursday 18 March 2021 18:29:50 andy pugh wrote: > On Thu, 18 Mar 2021 at 20:52, Frank Tkalcevic > > wrote: > > Is there anything special about driving these motors? > > I guess that as they are 20-step motors it is a long way between the > poles, and microstepping relies on finding an

Re: [Emc-users] Spindle rps and index

2021-03-18 Thread John Dammeyer
> -Original Message- > From: Jon Elson [mailto:el...@pico-systems.com] > Sent: March-18-21 6:22 PM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] Spindle rps and index > > On 03/18/2021 05:18 PM, Nicklas SB Karlsson wrote: > > Need to orient spindle. Using a

Re: [Emc-users] Spindle rps and index

2021-03-18 Thread Jon Elson
On 03/18/2021 05:18 PM, Nicklas SB Karlsson wrote: Need to orient spindle. Using a quadrature encoder spindle need to be "homed" by rotating up to one revolution to find index pulse but there is no homing for spindle. Know what index pulse is in encoder but what does the index enable signal

Re: [Emc-users] OT: Driving tiny steppers

2021-03-18 Thread Thaddeus Waldner
I once built a few tiny 3D printers out of old CD ROM drives with my students. The motors are no larger than 15mm. I was able to use the finest micro-stepping that those drivers are capable of. We did nothing out of the ordinary to hook them up; the motor plugged directly in to the RAMPS board.

Re: [Emc-users] OT: Driving tiny steppers

2021-03-18 Thread andy pugh
On Thu, 18 Mar 2021 at 20:52, Frank Tkalcevic wrote: > Is there anything special about driving these motors? I guess that as they are 20-step motors it is a long way between the poles, and microstepping relies on finding an elastic equilibrium between poles. I think that it is often like you

[Emc-users] Spindle rps and index

2021-03-18 Thread Nicklas SB Karlsson
Need to orient spindle. Using a quadrature encoder spindle need to be "homed" by rotating up to one revolution to find index pulse but there is no homing for spindle. Know what index pulse is in encoder but what does the index enable signal for spindle do? or how is it used? There is a float

[Emc-users] OT: Driving tiny steppers

2021-03-18 Thread Frank Tkalcevic
I have some small 15mm steppers, similar to this. https://www.aliexpress.com/item/32872829855.html I am trying to drive them with an A4988 stepper driver. I can run them at full step and half step, but anything smaller and they don't move linearly - one phase appears to step correctly,