diff --git a/Grbl_Esp32/Machines/pen_laser.h b/Grbl_Esp32/Machines/pen_laser.h
index 036415eb..eb405f2e 100644
--- a/Grbl_Esp32/Machines/pen_laser.h
+++ b/Grbl_Esp32/Machines/pen_laser.h
@@ -51,7 +51,7 @@
 
 // If SPINDLE_PWM_PIN is commented out, this frees up the pin, but Grbl will still
 // use a virtual spindle. Do not comment out the other parameters for the spindle.
-#define SPINDLE_PWM_PIN    GPIO_NUM_17 // Laser PWM
+//#define SPINDLE_PWM_PIN    GPIO_NUM_17 // Laser PWM
 
 #define USING_SERVO  // uncomment to use this feature
 //#define USING_SOLENOID // uncomment to use this feature
@@ -59,8 +59,8 @@
 #ifdef USING_SERVO
     #define USE_SERVO_AXES
     #define SERVO_Z_PIN     GPIO_NUM_27
-    #define SERVO_Z_RANGE_MIN 0
-    #define SERVO_Z_RANGE_MAX 10
+    #define SERVO_Z_RANGE_MIN 0.0
+    #define SERVO_Z_RANGE_MAX 10.0
 #endif
 
 #ifdef USING_SOLENOID
@@ -99,8 +99,8 @@
 
 #define DEFAULT_LASER_MODE 0 // false
 
-#define DEFAULT_X_STEPS_PER_MM 80
-#define DEFAULT_Y_STEPS_PER_MM 80
+#define DEFAULT_X_STEPS_PER_MM 80.0
+#define DEFAULT_Y_STEPS_PER_MM 80.0
 #define DEFAULT_Z_STEPS_PER_MM 100.0 // This is percent in servo mode...used for calibration
 
 #define DEFAULT_X_MAX_RATE 5000.0 // mm/min
diff --git a/Grbl_Esp32/grbl.h b/Grbl_Esp32/grbl.h
index fc755335..e42c1b0c 100644
--- a/Grbl_Esp32/grbl.h
+++ b/Grbl_Esp32/grbl.h
@@ -20,7 +20,7 @@
 
 // Grbl versioning system
 #define GRBL_VERSION "1.1f"
-#define GRBL_VERSION_BUILD "20200417"
+#define GRBL_VERSION_BUILD "20200419"
 
 //#include <sdkconfig.h>
 #include <Arduino.h>
diff --git a/Grbl_Esp32/servo_axis.h b/Grbl_Esp32/servo_axis.h
index fefb71af..75d4bb35 100644
--- a/Grbl_Esp32/servo_axis.h
+++ b/Grbl_Esp32/servo_axis.h
@@ -79,7 +79,7 @@
 #define SERVO_CAL_MIN 20.0 // Percent: the minimum allowable calibration value
 #define SERVO_CAL_MAX 180.0 // Percent: the maximum allowable calibration value
 
-#define SERVO_TIMER_INT_FREQ 20 // Hz This is the task frequency
+#define SERVO_TIMER_INT_FREQ 20.0 // Hz This is the task frequency
 
 #define SERVO_HOMING_OFF 0 // servo is off during homing
 #define SERVO_HOMING_TARGET 1 // servo is send to a location during homing
diff --git a/Grbl_Esp32/spindle_control.cpp b/Grbl_Esp32/spindle_control.cpp
index a7f0f7b2..52d26bad 100644
--- a/Grbl_Esp32/spindle_control.cpp
+++ b/Grbl_Esp32/spindle_control.cpp
@@ -56,7 +56,7 @@ void spindle_init() {
     pinMode(SPINDLE_DIR_PIN, OUTPUT);
 #endif
     // use the LED control feature to setup PWM   https://docs.espressif.com/projects/esp-idf/en/latest/api-reference/peripherals/ledc.html
-    spindle_pwm_chan_num = sys_get_next_PWM_chan_num();
+    spindle_pwm_chan_num = 0; // spindle always uses channel 0
     ledcSetup(spindle_pwm_chan_num, (double)settings.spindle_pwm_freq, SPINDLE_PWM_BIT_PRECISION); // setup the channel
     ledcAttachPin(SPINDLE_PWM_PIN, spindle_pwm_chan_num); // attach the PWM to the pin
     // Start with spindle off off
diff --git a/Grbl_Esp32/system.cpp b/Grbl_Esp32/system.cpp
index 635e6bee..46d78710 100644
--- a/Grbl_Esp32/system.cpp
+++ b/Grbl_Esp32/system.cpp
@@ -589,12 +589,20 @@ int8_t sys_get_next_RMT_chan_num() {
     }
 }
 
+/*
+    This returns an unused pwm channel.
+    The 8 channels share 4 timers, so pairs 0,1 & 2,3 , etc
+    have to be the same frequency. The spindle always uses channel 0
+    so we start counting from 2.
+    There are still possible issues if requested channels use different frequencies
+    TODO: Make this more robust.
+*/
 int8_t sys_get_next_PWM_chan_num() {
-    static uint8_t next_PWM_chan_num = 0; // channels 0-7 are valid
+    static uint8_t next_PWM_chan_num = 2; // start at 2 to avoid spindle
     if (next_PWM_chan_num < 8)  // 7 is the max PWM channel number
         return next_PWM_chan_num++;
     else {
         grbl_msg_sendf(CLIENT_SERIAL, MSG_LEVEL_ERROR, "Error: out of PWM channels");
         return -1;
     }
-}
\ No newline at end of file
+}