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IndustryArena Forum > CNC Electronics > Spindles / VFD > PWM not allowing max spindle speed
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  1. #1
    Join Date
    Jun 2009
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    10

    PWM not allowing max spindle speed

    G,day,

    I have a problem with my router spindle. Have changed from an nc studio set up to mach 3 ESS. My spindle will now not go to max speed. Voltage being output from my speed controller will not exceed 9.25 volts. This is the second speed controller I have installed with same results so my guess is it is something to do with the PWM signal from my ESS. Is there a setting I am not trying? Nothing I try seems to work. Any help appreciated

  2. #2
    Join Date
    Jan 2018
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    1516

    Re: PWM not allowing max spindle speed

    How much voltage (psu) are you putting into the 0-10v control area?
    My bob allows 12-24v psu. If I use 12v mine wouldn't reach max either.

  3. #3
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    Re: PWM not allowing max spindle speed

    I am using 12 v power supply. I think the board gives the option of 5v up to 24 v.

  4. #4
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    Re: PWM not allowing max spindle speed

    Quote Originally Posted by dtimes View Post
    I am using 12 v power supply. I think the board gives the option of 5v up to 24 v.
    Try nearer 24v like a converted laptop type or a Meanwell type.

  5. #5
    Join Date
    Mar 2007
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    2083

    Re: PWM not allowing max spindle speed

    which Breakout Board are you using ?

    some require a regulated 10V supply for the PWM to analogue converter

    others have an onboard regulator to reduce a 12 to 24V DC supply to the 10V

    a few BOB's have a potentiometer to adjust the PWM converters analogue output

    like the C6 board from CNC4PC for example
    http://www.cnc4pc.com/Tech_Docs/C6R6_User_Manual.pdf


    John

  6. #6
    Join Date
    Mar 2017
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    411

    Re: PWM not allowing max spindle speed

    The ESS only puts out a 5 volt PWM signal. Your speed controller has to convert that to 0-10 Volts DC. Usually there is a potentiometer on the speed controller that lets you adjust the output voltage. You should tell us what you have wired in between the ESS and the Spindle motor.

  7. #7
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    Jun 2009
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    10

    Re: PWM not allowing max spindle speed

    I might give 24 volt a go.

  8. #8
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    Jun 2009
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    Re: PWM not allowing max spindle speed

    The board I am using now is a C69 from cnc4pc. The trim pot is up to max already. I think given that both controllers I tried gave the same result, the problem may be further up the control chain. Maybe an ESS setting ??

  9. #9
    Join Date
    Jan 2005
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    15362

    Re: PWM not allowing max spindle speed

    Quote Originally Posted by dtimes View Post
    The board I am using now is a C69 from cnc4pc. The trim pot is up to max already. I think given that both controllers I tried gave the same result, the problem may be further up the control chain. Maybe an ESS setting ??
    Going to a higher voltage won't change anything unless the 12v supply is not giving you 12v

    Depending on your VFD some can use 0-5v or 0-10v so if you post what VFD Drive you have I may have the fix for you as long as you can get it down to 0-5v then this will work the same a 0-10v if your VFD Drive supports 0-5v
    Mactec54

  10. #10
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    Mar 2007
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    2083

    Re: PWM not allowing max spindle speed

    which speed controller are you using ?


    looking at the C69 manual from cnc4pc

    the board has a 5V to isolated 12V inverter modual to power the PWM to analogue converter
    possibly a B0512S-1W
    https://cms.nacsemi.com/content/Auth...00328644-1.pdf
    Click image for larger version. 

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    whats the C69's maximum analogue voltage when its disconnected from the speed controller ?

    if its 10V or more the input resistance of the speed controller could be too low and over loading the C69's analogue output

    if its less than 10V I would look at take a closer look at the soltware settings
    the PWM pulses must be too narrow

    John

  11. #11
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    Re: PWM not allowing max spindle speed

    Quote Originally Posted by john-100 View Post
    which speed controller are you using ?


    looking at the C69 manual from cnc4pc

    the board has a 5V to isolated 12V inverter modual to power the PWM to analogue converter
    possibly a B0512S-1W
    https://cms.nacsemi.com/content/Auth...00328644-1.pdf
    Click image for larger version. 

Name:	B0512S-1W.jpg 
Views:	5 
Size:	157.1 KB 
ID:	426104


    whats the C69's maximum analogue voltage when its disconnected from the speed controller ?

    if its 10V or more the input resistance of the speed controller could be too low and over loading the C69's analogue output

    if its less than 10V I would look at take a closer look at the soltware settings
    the PWM pulses must be too narrow

    John
    Yes he could have some settings not set correct

    PWM Base Frequency in Mach3 and the Smooth Stepper need to be both the same at 100Hz and the Pules width in the Smooth Stepper should be at 4.0, in Mach3 the Step Pulse and Dir Pulse is not used with the Smooth Stepper
    Attached Thumbnails Attached Thumbnails Step and Dir Pulse in Mach3.PNG   PWM SmoothStepper Setup.PNG   PWM Smooth Stepper and Mach3.PNG   PWM SmoothStepper Setup.PNG  

    PWM Smooth Stepper and Mach3.PNG  
    Mactec54

  12. #12
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    Re: PWM not allowing max spindle speed

    I checked the settings you suggested and they are all ok. I was running the frequency at 300 hz so changed to 100 hz but had no affect. The inverter is a fuling DZB series

  13. #13
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    Re: PWM not allowing max spindle speed

    Quote Originally Posted by dtimes View Post
    I checked the settings you suggested and they are all ok. I was running the frequency at 300 hz so changed to 100 hz but had no affect. The inverter is a fuling DZB series
    Play with the pulley ratio in Mach3 and see if that has any affect on the output voltage

    DBZ what number after the DBZ they have many different models
    Mactec54

  14. #14
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    Re: PWM not allowing max spindle speed

    I have tried many different settings in the pulley ratios but has given no affect. The number is DZB312B003.7L2DK

  15. #15
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    Re: PWM not allowing max spindle speed

    Quote Originally Posted by dtimes View Post
    I have tried many different settings in the pulley ratios but has given no affect. The number is DZB312B003.7L2DK
    Ok the Pulley Settings in Mach3 should be, you can play with the max speed number to see if this will change the output

    Min speed=0
    Max speed=24000
    Ratio=1

    I don't think it is anything to do with the VFD Drive the PWM voltage is to low to drive it at max speed so this has to be corrected before you can look at the VFD settings

    What speed did the spindle reach

    Did you do a Auto tune with the VFD Drive, this won't be affective unless the main Parameters are set first
    Mactec54

  16. #16
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    Re: PWM not allowing max spindle speed

    That's the pulley settings I am using. My inverter reads 377 instead of the 400 it should be. not sure of exact rpm. Not sure what you mean by auto tune.

  17. #17
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    Re: PWM not allowing max spindle speed

    Quote Originally Posted by dtimes View Post
    That's the pulley settings I am using. My inverter reads 377 instead of the 400 it should be. not sure of exact rpm. Not sure what you mean by auto tune.
    Play with the max speed setting in the pully settings try 25000 Etc.

    Your VFD Drive has Auto Tune, this will set any missing Parameters related to the motor and anything else that has been missed, Only do this once the main Parameters and Motor Parameters have been set F1.11=1 for Auto Tune
    Mactec54

  18. #18
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    1740

    Re: PWM not allowing max spindle speed

    As I understand Mach3 was only designed for 0-5 volts as a PWM signal. Its origin was a parallel port and that was max voltage. To get the 0-10 volt true output you might need to supply more than 12 volts to the control board, because of the voltage drop in the circuits. PWM and 0-10 vdc are not really the same thing. So to get the true 0-10 vdc the VFD needs, the controller board your using needs to convert that 0-5 PWM signal to 0-10 vdc. I also have a Warp9 ESS and its fine.
    Retired Master Electrician, HVAC/R Commercial. FLA Saturn 2 4x4 CNC Router Mach4 Kimber 1911 45ACP

  19. #19
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    Mar 2017
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    411

    Re: PWM not allowing max spindle speed

    Just a bit of clarification for anyone who is interested.

    Definition of terms.

    Binary Digital Signal: A voltage on a wire consisting of either a one or a zero. A digital "1" is represented by the presence of a voltage and a "0" is represented by the absence of a voltage or ground.

    Analog signal: Has several definitions, however we are interested in it as A signal on a wire where the voltage level of the signal represents the information being conveyed.

    TTL: "Transistor Transistor Logic" is a type of digital signal where a "1" is represented by 5 volts and a "0" is represented by zero volts. The actual voltages of a "0" can be 0.0 volts to 0.8 volts a "1" can be 2.0 volts to 5.0 volts.

    CMOS: This is similar to a TTL signal, however, the voltages are different. A CMOS signal can operate up to 15 volts. However, 3.3 Volts is the most common supply used. In a 3.3 Volt CMOS circuit, a "0" is 0-1.1 volts and a "1" is 2.2-3.3 Volts.

    PWM: Pulse Width Modulation is the use of a digital signal that represents data based on time. Any type of digital logic level can be used to represent a "1" or a "0" in a PWM signal but the length of time that the signal is a 1 or a 0 is the representation of the data. In the case of a PWM signal being used to represent the speed of a motor, it is the duty cycle of the signal that is used to represent the speed based on percentage. example: The signal is "1" for 1/2 second and "0" for 1/2 second this would be a 50% duty cycle. The motor would run at 50% of its maximum speed. Also in this example the PWM signal would have a frequency of 1 cycle per second or 1Hz. A second example might be a duty cycle of 90% with a frequency of 100Hz. 100Hz = 10 mili-seconds. 90% of 10 mili-seconds = 9 mili-seconds. So the signal would be "1" for 9 mS and "0" for 10mS.

    Parallel port: The original IBM PC included a port to send data to printers. The port used TTL signaling. There were 8 outputs, 5 inputs, and 4 bidirectional signals. Anything that is parallel port compatible uses TTL signaling, 0-5 volts.


    In the case of using a PWM signal to drive a VFD 0-10 volt speed input, several things have to happen. The parallel port must output a TTL signal with a varying duty cycle from 0 to 100%. The output from the parallel port must then be converted to a voltage where 0 volts represents 0% and 10 volts represents 100%.

    As several have suggested, it seems that the PWM output from the ESS is probably not 100% duty cycle. 100% would be a continuous 5 volts signal. One way to test is to use a 5Volt supply and connect it directly to the C69 input pin. The speed control output should then be 10 volts or close to it. Adjusting the potentiometer on the C69 board will allow you to adjust to 10 volts output with a 100% PWM signal input. Then when you reconnect the ESS board, the C69 speed control output will represent the PWM input. Since I am not familiar with Mach 3, I can't recommend more than that.

    The C69 documentation states that it requires a 5 Volt DC supply voltage at 300 millivolts. On the board there is a charge pump converter that boosts 5 Volts to 12 Volts for the 0-10 volt spindle speed control output. I would not connect a higher voltage than the manufacturer recommends. If you have already connected voltage higher than 5V you may have damaged the charge pump or the op-amp that converts the PWM TTL signal to analog 0-10V.

  20. #20
    Join Date
    Sep 2005
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    1740

    Re: PWM not allowing max spindle speed

    Interesting and valuable information. Link to owners manual https://www.cnc4pc.com/pub/media/pro...ser_manual.pdf
    Retired Master Electrician, HVAC/R Commercial. FLA Saturn 2 4x4 CNC Router Mach4 Kimber 1911 45ACP

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