diff --git a/docs/electronics/Motors.md b/docs/electronics/Motors.md
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--- a/docs/electronics/Motors.md
+++ b/docs/electronics/Motors.md
@@ -1,13 +1,14 @@
# Motors for Motion Control Applications
----
+
Choosing the right motor is critical for the efficiency and productivity of the motion control applications. It can be difficult to choose between servo motors and stepper motors as there are so many considerations: cost, torque, efficiency, speed, circuitry and more.
+---
## Differences in Servo Motors and Stepper Motors for Motion Control Applications:
---
- The main difference between these motors comes from the overall pole count. Stepper motors have a high pole count, usually between 50 and 100. Servo motors have a low pole count – between 4 and 12.
- This difference in pole count means that stepper motors move incrementally with a consistent pulse in a closed loop system. Servo motors require an encoder to adjust pulses for position control.
-
+---
## Stepper Motors in Motion Control: Pros and Cons
---
@@ -24,7 +25,7 @@ Choosing the right motor is critical for the efficiency and productivity of the
- They produce high vibrations levels and are prone to resonance issues.
- Stepper motors also produce high amounts of heat, which can be an issue in certain applications.
-
+---
## Servo Motors in Motion Control: Pros and Cons
---
> Pros:
@@ -39,33 +40,49 @@ Choosing the right motor is critical for the efficiency and productivity of the
- Servo motors are more expensive than stepper motors. Add in the cost of an encoder, and often a gearbox, and the whole system can become quite costly.
- The need for an encoder and gearbox makes the system more mechanically complex, leading to more frequent maintenance and higher costs.
-
+---
## Key Questions of Stepper Motors:
---
-### How to Choose Steppers Motors for DIY CNC machines?
+
+A stepper motor can be a good choice whenever controlled movement is required. They can be used in applications where we need to control rotation angle, speed, position and synchronism. Because of the inherent advantages listed previously, stepper motors have found their place in many different applications. Some of these include printers, plotters, X-Y tables, laser cutters, engraving machines, pick-place devices and so on.
+
+---
+### **How to Choose Steppers Motors for DIY CNC machines?**
---
-Choosing a stepper very much depends on the type of machine you have or are going to build and the material you are going to cut. The most technical ways of choosing the stepper motors are mentioned in [Motor Sizing](https://www.orientalmotor.com/technology/motor-sizing-calculations.html). This repository contains the simplest way to choose a stepper motor for the DIY CNC machines. You can find more details in [Stepper Motors and Controllers](https://rckeith.co.uk/how-to-choose-steppers-motors-and-controllers-for-diy-cnc-machines/). Let's start with understanding the NEMA standard.
+
+Choosing a stepper very much depends on the type of machine we have or are going to build and the material we are going to cut. When selecting a stepper motor for our application, there are several factors that need to be taken into consideration:
+
+- How will the motor be coupled to the load?
+- How fast does the load need to move or accelerate?
+- How much torque is required to move the load?
+- What degree of accuracy is required when positioning the load?
+
+The most technical ways of choosing the stepper motors are mentioned in [Motor Sizing](https://www.orientalmotor.com/technology/motor-sizing-calculations.html). This repository contains the simplest way to choose a stepper motor for the DIY CNC machines. More details can be found in [Stepper Motors and Controllers](https://rckeith.co.uk/how-to-choose-steppers-motors-and-controllers-for-diy-cnc-machines/). Let's start with understanding the **NEMA** standard.
+
+---
+ > #### Nema Standard:
- NEMA (National Electrical Manufacturers Association) is a standard that defines the size of the faceplate of the motor.
- Two of the most popular sizes for DIY machines are NEMA17 (1.7 in x 1.7 in) and NEMA23 (2.3 in x 2.3 in).
---
-### How to Understand the Stepper Motor Specifications?
+### **How to Understand the Stepper Motor Specifications?**
---
- > #### 1) Unipolar / Bipolar
+
+ > #### 1) Rated Current
---
-- Stepper motors can be bipolar or unipolar. This has to do with the way coils are connected. Nearly all motors for hobby CNC machines are sold as bipolar.
+- This is the maximum current we may pass through both windings at the same time.
-- A bipolar stepper motor has an onboard driver that uses an H bridge circuit to reverse the current flow through the phases. By energizing the phases while alternating the polarity, all the coils can be put to work turning the motor.
-
-- In practical terms, this means that the coil windings are better utilized in a bipolar than a standard unipolar stepper motor (which only uses 50% of the wire coils at any one time), making bipolar stepper motors more powerful and efficient to run.
+- The maximum current through one winding (which is what really matters when using microstepping) is rarely quoted and will be a little higher.
+
+- However, even with one winding driven at the quoted rated current, the motor will get very hot.
-- For the same reason, bipolar motors have a high torque output. To learn more about the wiring, check this [Wiring Configurataion](https://blog.orientalmotor.com/wiring-basics-unipolar-vs-bipolar).
+- The usual practice is to set the motor current to no more than about 85% of the rated current.
-- However, the motors need more complex circuitry to switch the coils. This isn’t an issue because the driver modules do this for us.
+- Therefore, to get maximum torque out of the stepper motors without overheating them, we should choose motors with a current rating no more than 25% higher than the recommended maximum stepper driver current.
---
- > #### 2) Torque Rating
+> #### 2) Torque Rating
---
- Stepper motors are rated by their holding torque in oz / in (ounces per inch) or N.m (Newton-metre), etc.
@@ -80,4 +97,54 @@ Choosing a stepper very much depends on the type of machine you have or are goin
- The torque is proportional to current (except at very low currents), so for example, if we set the drivers to 85% of the motor rated current, then the maximum torque will be ***85% * 0.707 = 60%*** of the specified holding torque.
---
+ > #### 3) Unipolar / Bipolar
+---
+- Stepper motors can be bipolar or unipolar. This has to do with the way coils are connected. Nearly all motors for hobby CNC machines are sold as bipolar.
+
+- A bipolar stepper motor has an onboard driver that uses an H bridge circuit to reverse the current flow through the phases. By energizing the phases while alternating the polarity, all the coils can be put to work turning the motor.
+
+- In practical terms, this means that the coil windings are better utilized in a bipolar than a standard unipolar stepper motor (which only uses 50% of the wire coils at any one time), making bipolar stepper motors more powerful and efficient to run.
+
+- For the same reason, bipolar motors have a high torque output. To learn more about the wiring, check this [Wiring Configurataion](https://blog.orientalmotor.com/wiring-basics-unipolar-vs-bipolar).
+
+- However, the motors need more complex circuitry to switch the coils. This isn’t an issue because the driver modules do this for us.
+---
+
+ > #### 4) Step angle
+---
+- There are two common step angles: 0.9 and 1.8 degrees per full step, corresponding to 400 and 200 steps/revolution.
+
+- 0.9 deg motors have slightly lower holding torque than similar 1.8 deg motors from the same manufacturer.
+
+---
+
+
+## Resistance and rated voltage
+---
+- These are simply the resistance per phase, and the voltage drop across each phase when the motor is stationary and the phase is passing its rated current (which is the product of the resistance and the rated current).
+
+- These are unimportant, except that the rated voltage should be well below the power supply voltage to the stepper driver.
+
+> The 0.4 A stepper motor has the rated phase voltage of 12 V (phase resistance_30 ohms * rated current per phase_0.4 A). Providing 12 V supply voltage to the **DRV8825** stepper motor controller IC, we must use the 1.8 A rated current stepper motor. Because it has the rated phase voltage of 2.7 V (phase resistance_1.5 ohms * rated current per phase_1.8 A), which is much lower than the supply voltage (12 V) compared to the 0.4 A stepper motor.
+
+## Inductance
+---
+
+- The inductance of the motor affects how fast the stepper motor driver can drive the motor before the torque drops off. If we temporarily ignore the back emf due to rotation and the rated motor voltage is much less than the driver supply voltage, then the maximum revs/second before torque drops off is:
+
+> ***revs_per_second = (2 * supply_voltage)/(steps_per_rev * pi * inductance * current)***
+
+)
+
+- If the motor is driving a GT2 belt via a pulley, this gives the maximum speed in mm/sec as:
+
+> ***speed = (4 * pulley_teeth * supply_voltage)/(steps_per_rev * pi * inductance * current)***
+
+- **Example**: a 1.8 deg/step (i.e. 200 steps/rev) motor with 3.2 mH inductance run at 1.5 A using a 12 V supply, and driving a GT2 belt with 20 tooth pulley would start losing torque at about 318 mm/sec. This is the belt speed, which on a CoreXY or delta printer is not the same as the head speed.
+
+- In practice the torque will drop off sooner than this because of the back emf caused by motion, and because the above doesn't allow for the winding resistance. Low inductance motors also have low back emf due to rotation.
+
+> What this means is that if we want to achieve high speeds, we need low inductance motors and high supply voltage. So, we must choose the 1.8 A stepper motor having lower inductance (3.2 mH) compared to the 0.4 A stepper motor (58 mH).
+
+