diff --git a/ArduCopter/motors_quad.pde b/ArduCopter/motors_quad.pde
index 849ecec2c2..e613cc6aa7 100644
--- a/ArduCopter/motors_quad.pde
+++ b/ArduCopter/motors_quad.pde
@@ -5,7 +5,7 @@
 static void init_motors_out()
 {
 	#if INSTANT_PWM == 0
-    APM_RC.SetFastOutputChannels( _BV(CH_1) | _BV(CH_2) | _BV(CH_3) | _BV(CH_4) );
+    APM_RC.SetFastOutputChannels( _BV(MOT_1) | _BV(MOT_2) | _BV(MOT_3) | _BV(MOT_4) );
 	#endif
 }
 
@@ -33,12 +33,12 @@ static void output_motors_armed()
 		pitch_out 	 	= g.rc_2.pwm_out * .707;
 
 		// left
-		motor_out[CH_3]	 	= g.rc_3.radio_out + roll_out + pitch_out;	// FRONT
-		motor_out[CH_2]	 	= g.rc_3.radio_out + roll_out - pitch_out;	// BACK
+		motor_out[MOT_3]	 	= g.rc_3.radio_out + roll_out + pitch_out;	// FRONT
+		motor_out[MOT_2]	 	= g.rc_3.radio_out + roll_out - pitch_out;	// BACK
 
 		// right
-		motor_out[CH_1]		= g.rc_3.radio_out - roll_out + pitch_out;  // FRONT
-		motor_out[CH_4] 	= g.rc_3.radio_out - roll_out - pitch_out;	// BACK
+		motor_out[MOT_1]		= g.rc_3.radio_out - roll_out + pitch_out;  // FRONT
+		motor_out[MOT_4] 	= g.rc_3.radio_out - roll_out - pitch_out;	// BACK
 
 	}else{
 
@@ -46,20 +46,20 @@ static void output_motors_armed()
 		pitch_out 	 	= g.rc_2.pwm_out;
 
 		// right motor
-		motor_out[CH_1]		= g.rc_3.radio_out - roll_out;
+		motor_out[MOT_1]		= g.rc_3.radio_out - roll_out;
 		// left motor
-		motor_out[CH_2]		= g.rc_3.radio_out + roll_out;
+		motor_out[MOT_2]		= g.rc_3.radio_out + roll_out;
 		// front motor
-		motor_out[CH_3]		= g.rc_3.radio_out + pitch_out;
+		motor_out[MOT_3]		= g.rc_3.radio_out + pitch_out;
 		// back motor
-		motor_out[CH_4] 	= g.rc_3.radio_out - pitch_out;
+		motor_out[MOT_4] 	= g.rc_3.radio_out - pitch_out;
 	}
 
 	// Yaw input
-	motor_out[CH_1]		+=  g.rc_4.pwm_out; 	// CCW
-	motor_out[CH_2]		+=  g.rc_4.pwm_out; 	// CCW
-	motor_out[CH_3]		-=  g.rc_4.pwm_out; 	// CW
-	motor_out[CH_4] 	-=  g.rc_4.pwm_out; 	// CW
+	motor_out[MOT_1]		+=  g.rc_4.pwm_out; 	// CCW
+	motor_out[MOT_2]		+=  g.rc_4.pwm_out; 	// CCW
+	motor_out[MOT_3]		-=  g.rc_4.pwm_out; 	// CW
+	motor_out[MOT_4] 	-=  g.rc_4.pwm_out; 	// CW
 
     /* We need to clip motor output at out_max. When cipping a motors
      * output we also need to compensate for the instability by
@@ -67,7 +67,7 @@ static void output_motors_armed()
      * ensures that we retain control when one or more of the motors
      * is at its maximum output
      */
-    for (int i=CH_1; i<=CH_4; i++) {
+    for (int i=MOT_1; i<=MOT_4; i++) {
         if (motor_out[i] > out_max) {
             // note that i^1 is the opposite motor
             motor_out[i^1] -= motor_out[i] - out_max;
@@ -76,24 +76,24 @@ static void output_motors_armed()
     }
 
 	// limit output so motors don't stop
-	motor_out[CH_1]		= max(motor_out[CH_1], 	out_min);
-	motor_out[CH_2]		= max(motor_out[CH_2], 	out_min);
-	motor_out[CH_3]		= max(motor_out[CH_3], 	out_min);
-	motor_out[CH_4] 	= max(motor_out[CH_4], 	out_min);
+	motor_out[MOT_1]		= max(motor_out[MOT_1], 	out_min);
+	motor_out[MOT_2]		= max(motor_out[MOT_2], 	out_min);
+	motor_out[MOT_3]		= max(motor_out[MOT_3], 	out_min);
+	motor_out[MOT_4] 	= max(motor_out[MOT_4], 	out_min);
 
 	#if CUT_MOTORS == ENABLED
 	// if we are not sending a throttle output, we cut the motors
 	if(g.rc_3.servo_out == 0){
-		motor_out[CH_1]		= g.rc_3.radio_min;
-		motor_out[CH_2]		= g.rc_3.radio_min;
-		motor_out[CH_3]		= g.rc_3.radio_min;
-		motor_out[CH_4] 	= g.rc_3.radio_min;
+		motor_out[MOT_1]		= g.rc_3.radio_min;
+		motor_out[MOT_2]		= g.rc_3.radio_min;
+		motor_out[MOT_3]		= g.rc_3.radio_min;
+		motor_out[MOT_4] 	= g.rc_3.radio_min;
 	}
 	#endif
 
 	// this filter slows the acceleration of motors vs the deceleration
 	// Idea by Denny Rowland to help with his Yaw issue
-	for(int8_t i=CH_1; i <= CH_4; i++ ) {
+	for(int8_t i=MOT_1; i <= MOT_4; i++ ) {
 		if(motor_filtered[i] < motor_out[i]){
 			motor_filtered[i] = (motor_out[i] + motor_filtered[i]) / 2;
 		}else{
@@ -102,10 +102,10 @@ static void output_motors_armed()
 		}
 	}
 
-	APM_RC.OutputCh(CH_1, motor_filtered[CH_1]);
-	APM_RC.OutputCh(CH_2, motor_filtered[CH_2]);
-	APM_RC.OutputCh(CH_3, motor_filtered[CH_3]);
-	APM_RC.OutputCh(CH_4, motor_filtered[CH_4]);
+	APM_RC.OutputCh(MOT_1, motor_filtered[MOT_1]);
+	APM_RC.OutputCh(MOT_2, motor_filtered[MOT_2]);
+	APM_RC.OutputCh(MOT_3, motor_filtered[MOT_3]);
+	APM_RC.OutputCh(MOT_4, motor_filtered[MOT_4]);
 
 	#if INSTANT_PWM == 1
 	// InstantPWM
@@ -130,52 +130,52 @@ static void output_motors_disarmed()
 	}
 
 	// Send commands to motors
-	APM_RC.OutputCh(CH_1, g.rc_3.radio_min);
-	APM_RC.OutputCh(CH_2, g.rc_3.radio_min);
-	APM_RC.OutputCh(CH_3, g.rc_3.radio_min);
-	APM_RC.OutputCh(CH_4, g.rc_3.radio_min);
+	APM_RC.OutputCh(MOT_1, g.rc_3.radio_min);
+	APM_RC.OutputCh(MOT_2, g.rc_3.radio_min);
+	APM_RC.OutputCh(MOT_3, g.rc_3.radio_min);
+	APM_RC.OutputCh(MOT_4, g.rc_3.radio_min);
 }
 
 /*
 //static void debug_motors()
 {
 	Serial.printf("1:%d\t2:%d\t3:%d\t4:%d\n",
-				motor_out[CH_1],
-				motor_out[CH_2],
-				motor_out[CH_3],
-				motor_out[CH_4]);
+				motor_out[MOT_1],
+				motor_out[MOT_2],
+				motor_out[MOT_3],
+				motor_out[MOT_4]);
 }
 //*/
 
 static void output_motor_test()
 {
-	motor_out[CH_1] = g.rc_3.radio_min;
-	motor_out[CH_2] = g.rc_3.radio_min;
-	motor_out[CH_3] = g.rc_3.radio_min;
-	motor_out[CH_4] = g.rc_3.radio_min;
+	motor_out[MOT_1] = g.rc_3.radio_min;
+	motor_out[MOT_2] = g.rc_3.radio_min;
+	motor_out[MOT_3] = g.rc_3.radio_min;
+	motor_out[MOT_4] = g.rc_3.radio_min;
 
 
 	if(g.frame_orientation == X_FRAME){
 //  31
 //	24
 		if(g.rc_1.control_in > 3000){
-			motor_out[CH_1] += 100;
-			motor_out[CH_4] += 100;
+			motor_out[MOT_1] += 100;
+			motor_out[MOT_4] += 100;
 		}
 
 		if(g.rc_1.control_in < -3000){
-			motor_out[CH_2] += 100;
-			motor_out[CH_3] += 100;
+			motor_out[MOT_2] += 100;
+			motor_out[MOT_3] += 100;
 		}
 
 		if(g.rc_2.control_in > 3000){
-			motor_out[CH_2] += 100;
-			motor_out[CH_4] += 100;
+			motor_out[MOT_2] += 100;
+			motor_out[MOT_4] += 100;
 		}
 
 		if(g.rc_2.control_in < -3000){
-			motor_out[CH_1] += 100;
-			motor_out[CH_3] += 100;
+			motor_out[MOT_1] += 100;
+			motor_out[MOT_3] += 100;
 		}
 
 	}else{
@@ -183,22 +183,22 @@ static void output_motor_test()
 // 2 1
 //	4
 		if(g.rc_1.control_in > 3000)
-			motor_out[CH_1] += 100;
+			motor_out[MOT_1] += 100;
 
 		if(g.rc_1.control_in < -3000)
-			motor_out[CH_2] += 100;
+			motor_out[MOT_2] += 100;
 
 		if(g.rc_2.control_in > 3000)
-			motor_out[CH_4] += 100;
+			motor_out[MOT_4] += 100;
 
 		if(g.rc_2.control_in < -3000)
-			motor_out[CH_3] += 100;
+			motor_out[MOT_3] += 100;
 	}
 
-	APM_RC.OutputCh(CH_1, motor_out[CH_1]);
-	APM_RC.OutputCh(CH_2, motor_out[CH_2]);
-	APM_RC.OutputCh(CH_3, motor_out[CH_3]);
-	APM_RC.OutputCh(CH_4, motor_out[CH_4]);
+	APM_RC.OutputCh(MOT_1, motor_out[MOT_1]);
+	APM_RC.OutputCh(MOT_2, motor_out[MOT_2]);
+	APM_RC.OutputCh(MOT_3, motor_out[MOT_3]);
+	APM_RC.OutputCh(MOT_4, motor_out[MOT_4]);
 }
 
 #endif