Spindle soft stop

Hi

I have a KBMG-212D for drive my lathe spindle, this one include a great regenerative brake.

This brake is i think too much efficient my motor does some Sparks at high RPM when braking.

Did you show a way for prevent this ?
I like if possible to ask and wait 0rpm or some low rpm before sending the stop signal. (disabling enable relay)

I does not really want to configure the drive for coast to stop because i want to keep the brake for some "Kill switch situation".

Br

Edit : for another project (mill retrofit) i like something like this for preventing to reverse spindle at too high rpm because this one use a relay for reverse spindle wire.

hmm i'm thinking about a simple "and2" and/or "near" component for enable output ??

Thanks this is good to know that is for you not a real problem !

I have try to add near and and2 but not work fine, so i have try with timedelay and this work fine ! (need pid.enable + enable output)


Before adding timedelay


After adding timedelay 0.85

I'm thinking about : something can/need to be done for spindle with regenerative brake using something like setp limit2.spindle-vel-rpm-cmd.maxv for manage stopping

IMH and after this test i suspect max deceleration need to be the same as max acceleration for motor safety.

What did you think ?

Would this example help?
linuxcnc.org/docs/2.7/html/examples/spin...#_spindle_soft_start

Thanks for reply.

This is related to what i have in my config with limit2 for smooth acceleration.

In my opinion the same type of things for deceleration before disabling enable signal is needed.

I have found a trick using timedelay that work fine !

But i like to speak about including something like this inside spindle modul or inside limit2 (really unsure where is the better place but not important for start speaking)

As you can see my engish is very bad so it's not really easy to be sure this is understandable.

If you have spindle speed feedback you could delay the disable until the RPM is below a minimum speed.
Most VFDs take care of this for you.

I believe the intention in the future is to have spindles more under linuxcnc's control.
In Master branch you can have many spindles and I think eventually they will have a component built in to control them more.
But with a VFD most of the control problems go away other then if you want spindle positioning mode.

Chris

I use master branch, I have not see a integrated parameter for disable spindle after delay I need to check more !

Did you know a modern vfd for brushed field DC motor 180v 1 to 2 hp ?

You would need to piece together the logic from smaller components or use comp to build a custom component. I don't know about a suitable drive.

Chris