Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: B3030 on June 07, 2014, 08:34:32 PM

Title: M5 does not completely stop the spindle
Post by: B3030 on June 07, 2014, 08:34:32 PM
I have a simple DC spindle on a Chinese router.
I'm using the Analog output from a CNC4PC C11 BOB to replace a potentiometer on a 1000W PWM Motor Speed Control that is driven by a 48VDC switching P/S.

The specs for the Speed Controller are as follows:
   Working voltage: DC 10V-50V
   Control Motor Power : 0.01-1000W (50V)
   Rated current: 30A(Max current 40A)
   Regulation range:5-100%

The spindle works fine and follows M3 commands to turn on, and "S" commands to change speed. The problem I have is that when I send an M5 code the spindle still rotates about 100-200 RPM.

The Speed Controller specs include the line: "Regulation range:5-100%".  Would that account for the spindle still spinning after the M5 command since it never commands it to 0%?

B3030
Title: Re: M5 does not completely stop the spindle
Post by: Hood on June 08, 2014, 10:06:42 AM
You will need to check the output from your speed controller to see if it is still outputting voltage when it is meant to be stopped.
There may also be stop/start inputs on your speed controller/drive which you need to wire up correctly, without knowing the specs of that I can not say, however it is normal for most drives to have a run input of some sort.
Hood
Title: Re: M5 does not completely stop the spindle
Post by: B3030 on June 08, 2014, 08:54:49 PM
I found the problem.

The Motor Speed Controller came with a switched potentiometer for control.  I wired the C11 analog output to the pot input and wired the switch part of the pot to a relay onboard the C11 correctly, but I hadn't enabled the relay in Ports and Pins. ::) 

I do have the minimum speed in the Pulley set to 0 so I still wonder why I still have that slow spin when I command a Spindle speed change of S0.  The relay now stops the spindle (for tool changes) so all is well.

Thanks for your reply Hood.

B3030
Title: Re: M5 does not completely stop the spindle
Post by: Hood on June 09, 2014, 01:33:02 PM
S0 command should theoretically stop the spindle but in reality there will be some slight voltage on the command signal wires and thus the spindle will slowly rotate.
Hood