Deskstop CNC Spindles    Digital Tooling

Arduino>PMW to Analog converter >Controlable power supply of Variable Frequency Drive.


New 600W CNC Spindle Motor Kits w/ PWM Speed Control Power Supply Mount Bracket ~$198

Arduino PWM to 1-10v DC   Article
Product=Power supply with this board added.
In config.h, is variable spindle enabled?

From config.h around line 335:

// Enables variable spindle output voltage for different RPM values. On the Arduino Uno, the spindle
// enable pin will output 5V for maximum RPM with 256 intermediate levels and 0V when disabled.
// NOTE: IMPORTANT for Arduino Unos! When enabled, the Z-limit pin D11 and spindle enable pin D12 switch!
// The hardware PWM output on pin D11 is required for variable spindle output voltages.
#define VARIABLE_SPINDLE // Default enabled. Comment to disable.

Arduino PWM to 1-10v Video

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Connections

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Map Output of GRBL to Pin 11


The CNC Router Spindle offers include quite a  wide spread of solutions and in my opinion the most confusing area of cnc due to it's often digital to analog conversion requirements.  AC electronics is one of the more challenging areas of electrical engineering to master.  The tools to visualize precisely  what is going on can be quite daunting.  DC
AC single phase
AC triple phase
Routers
Related Topics:
Arduino GRBL setup
2 Stepper Motors one Axis
External Stepper Drivers on Protoneer Arduino Board

Arduino Enclosure
Mapping the PWM out and
adjusting the voltage curve

Hall sensors Motor Speed Controller

                                 
For optimal results it needs speed control. This can range from...
Tools like routers and moto tools with built in speed controls
The same using off the shelf controllers like the Harbor Freight router speed control		 DC controllers.
AC  Controllers
Variable Frequency Drives
First of all control of the spindle is not available on all boards but is available by different means via software control.
GRBL  Mach3  LINUX CNC ...
First we will focus on GRBL as that this is the most accessible platform for most folks entering the platform of desktop manufacturing.  

Arduino PWM to 1-10v DC   Article
Product=Power supply with this board added.
In config.h, is variable spindle enabled?

From config.h around line 335:

// Enables variable spindle output voltage for different RPM values. On the Arduino Uno, the spindle
// enable pin will output 5V for maximum RPM with 256 intermediate levels and 0V when disabled.
// NOTE: IMPORTANT for Arduino Unos! When enabled, the Z-limit pin D11 and spindle enable pin D12 switch!
// The hardware PWM output on pin D11 is required for variable spindle output voltages.
#define VARIABLE_SPINDLE // Default enabled. Comment to disable.

 Arduino PWM to 1-10v Video
Buy Board
Connections
Buy USA
Map Output of GRBL to Pin 11
The default potentiometer control is 5K-100K, the defaults is 10K. MACH3 -PWM speed control signal input, external PWM input requirements: level 3.5-12V VPP, frequency
1K-10KHZ, suitable for MACH3 spindle speed control. Soft-start function. Prevent excessive current caused by the motor and power damage (default 0 seconds soft start),
0-5 seconds adjustable. Control power: 12V120W, 24V240W, 36V360W,
48V480W, 60V600W.

Routers DC Motor
 AC Motor 3 Phase (Open image)
 AC Motor Single Phase
 Water Cooled
 Air Cooled
Manual
Simplest
~$15 Router Speed
Tachometer ~$60
Bosch Router
Dewalt Router






GRBL
PWM Converter
Arduino Connections

.8kw  Link

Arduino Signal
Conversion
 Variable Frequency Drive
VFD
Video


Mach 3 $189
Pricier
Purchase
Artsoft
DC Controller ~$198
 VFD Setup




LINUX CNC













Arduino Connections

Connection PWM to 1-10v analog
]
QPX board








Mach 3 What the converter does is two-fold:

1.  Averages the voltage of the pulses to get an analog voltage between 0 and 5V DC based on the duty cycle (percentage value described above).
2.  Amplifies this voltage from the 0 - 5V DC analog signal generated in step 1 (this average cannot be higher than the peak voltage applied) and generates the 0 - 10V DC signal required to run the inverter to drive the spindle motor at the desired RPM.

What will happen if you do not run the PWM signal to the converter is that you will be applying a 5V DC digital signal to an analog input.  Depending on the design of the input stage of the inverter, it may "see" 5V DC and command a speed of 50 percent which is close to the 10800 RPM you are seeing when you first start up the spindle with the button on Mach3.  However, the inverter will probably not handle the averaging function well and will give erratic speeds as you vary the duty cycle of the PWM signal but as you've seen in your trials, it will never be above 50 percent of the available RPM.

You need to run the PWM signal through a converter unless your BOB or Smoothstepper has one built in.  This will generate the appropriate 0 - 10V DC analog signal required by the inverter input.  Also, note that the actual speeds may not be as accurate since there could be some non-linearity introduced in either the converter, the input stage of the inverter, or both.

Hope this all makes sense.  Let me know if you do have this PWM to analog converter or a 0 - 10V analog DC output on your controller/BOB.