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Author Topic: Mach 4 Spindle Speed Control  (Read 3334 times)

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Mach 4 Spindle Speed Control
« on: June 11, 2018, 07:44:57 PM »
Hello again everyone,
Need some help with my spindle speed control with Mach 4.
My setup is Mach4, ESS Smoothstepper on a MB2 BOB. I'm using a Teco/Westinghouse L510 VFD with 2.2Kw (400hz) water cooled spindle.
I've got VFD working with Mach4, so if I enter an M3 S----- command the spindle turns on, but it runs at either 60Hz or 400hz, ( 3500 or 24000rpm)
does not matter what the rpms I'm asking for. I've got ESS spindle programmed for PWM and I
have PID checked. I was hoping someone out there has a similar setup or is using a Teco VFD and can help
me out. I'm thinking I need to program the PID function in the VFD but not quite sure. I'm enclosing the
manual for the Teco L510-203-H3-U.
Thanks again, Richard
Re: Mach 4 Spindle Speed Control
« Reply #1 on: June 12, 2018, 02:08:08 AM »
Have you got some smoothing in the PWM output that feeds the speed control input on the VFD?  Also the VFD speed control voltage range is usually 0 - 10V whereas the PWM output is more likely pulsing between 0 and 5 V so it needs some gain.
Re: Mach 4 Spindle Speed Control
« Reply #2 on: June 12, 2018, 03:17:40 PM »
Hi,
you don't say if you have an spindle index signal?

If not the PID wont work. The PID procedure needs a way of measuring the actual current spindle speed and without an index signal it can't do it.
In absence of proper feedback I would expect the closed loop controller, aka the PID, to be either max, ie 24000 rpm or under slightly different circumstances
minimum, I suspect in your case the VFD is programmed to 3500 rpm min.
Uncheck the PID setting and the PWM and spindle will perform  open loop. You might reasonably expect accuracy of 5-10%.

Craig
My wife left with my best friend...
     and I miss him!
Re: Mach 4 Spindle Speed Control
« Reply #3 on: June 12, 2018, 05:23:26 PM »
Hey Craig,
Thanks for your reply. I'm pretty new to all this programming, so not sure what a spindle index signal is.
Trying to master one thing at a time with Mach4 and the ESS, so far so good.
I am attaching a diagram that Weerasak from CNCRoom sent me to get things going.
I do know that I have not enabled anything for spindle index signal.
As long as I can set an M3 S---- command and its somewhat close that's fine with me until I get a little
deeper into this new hobby of mine.
In the mean time I will uncheck PID on ESS and see what happens.
Thanks Again.
Re: Mach 4 Spindle Speed Control
« Reply #4 on: June 12, 2018, 06:28:37 PM »
Hi,
an index pulser is a device attached to the spindle to generate a signal each time the rotor turns. If you don't
know what it is...you don't have one. Uncheck PID, you are not able to use it.

Craig
My wife left with my best friend...
     and I miss him!
Re: Mach 4 Spindle Speed Control
« Reply #5 on: June 12, 2018, 10:22:02 PM »
Yup so once running correctly you should have a range of voltages between 1 and 10v if you measure between AGND and AVI on your Teco.
If you are getting the correct voltage there then you have a setting wrong in your Teco somewhere. If you arnt getting that voltage then you have settings wrong in Mach4 or wiring wrong
Re: Mach 4 Spindle Speed Control
« Reply #6 on: June 13, 2018, 04:41:41 PM »
Thanks everyone, Unchecked PID in ESS and everything working as expected.
M3 S 1000 = aprox 1000rpm, M3 S5000 = aprox 5000rpm and so on up to 24000rpm.
I can even adjust on Mach4 screen settings down to 50% or up to 150%.
I'm now 2 for 2 on getting a problem solved with just on check mark.
Thanks again.
My wife left with my best friend...
     and I miss him!
Re: Mach 4 Spindle Speed Control
« Reply #8 on: June 13, 2018, 05:21:47 PM »
I looked at Teco L510 VFD manual again and I can change HZ to RPM on my VFD Digital Screen.
Section 6.4 Change Output Frequency Unit from Hz to rpm.
Program section 12-03.
If I need to be precise on my speed I can always open VFD cabinet and double check speed from there.

 
Re: Mach 4 Spindle Speed Control
« Reply #9 on: June 14, 2018, 07:04:31 AM »
Hi,
yes what I've outlined is precise but that's less important than if you have an index signal Mach can display the actual speed on screen....you don't have to do
anything, its already built in. So it makes sense if there is such a thing as a synthesized index signal from your VFD then for the sake of a piece of wire to hook it to
a spare input on your controller/BoB, dozen keystrokes in the plugin to turn it on and viola...accurate, live spindle speed on screen.

Craig
My wife left with my best friend...
     and I miss him!