Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Vogavt on August 13, 2013, 01:55:30 PM

Title: Ramping up or down on Spindle Speed (not delay)
Post by: Vogavt on August 13, 2013, 01:55:30 PM

Is there a way to ramp the spindle speed up to full speed instead of "full out" when the spindle starts?

I know about the delay function, but that's not wihat I'm looking for.

I'd like for the spindle to come up to speed in a smooth fluid motion not the way it does now which is almost intantaneous.

I've played with the motor tuning for the spindle, i.e. Acceleration and Velocity, but thoes don't make any difference best I can tell.

Title: Re: Ramping up or down on Spindle Speed (not delay)
Post by: geh7552 on August 14, 2013, 07:27:35 AM

The VFD spindle drive has ramp rate accel and deaccel parameters. Most drives are factory default to 5 seconds ramp rate. Sounds like your setting is zero.  Try setting the accel ramp rate to 10 seconds, or any setting to your liking. 

Title: Re: Ramping up or down on Spindle Speed (not delay)
Post by: Sam on August 16, 2013, 01:23:09 AM

And.....make sure the delay is set long enough to accompany the ramp up/down.

Title: Re: Ramping up or down on Spindle Speed (not delay)
Post by: Vogavt on August 24, 2013, 09:28:57 AM

I'm using a KBLC-19PM-mod to drive the spindle. So you're saying there should be a pot on the unit that I can adjust?

Don't recall seeing one but definitely worth a second look.

Thanks!



EDIT:
Yep there it is and just think, it was there all along! LOL!

http://www.kbelectronics.com/manuals/kblc.pdf

Title: Re: Ramping up or down on Spindle Speed (not delay)
Post by: Vogavt on September 17, 2014, 07:58:26 AM

Okay, I'm having to backup on my findings. I've been doing a major overhaul on my setup this summer so I'm just now getting back to this issue.

The documentation shows there should be a potentiometer for the KBIC/KBLC controllers. However, even though the PCB has a slikscreen indicating the location where the pot should be, it doesn't exist on the KBLC-19PM. I have three of these controllers and all the same. No physical pot for ACCEL.  Bummer.....

So I'm revisiting a means to getting control of that slamming on of the spindle. I just can't tolerate the instantaneous jerking of the belt drive and am not comfortable with the whole process and what it may be doing to other components, i.e., pulley shaft, set screws, etc.

One way that I've come up with is searching and replacing the M3 S??? in the gcode with a gradual increasing of RPM until it gets to where it's supposed to be.

There's just got to be a better way so any ideas would be appreciated.

I think I found the solution here (http://www.machsupport.com/forum/index.php/topic,8289.0.html)