# Microstepping, Gearing, and Torque

• SquidPhysics
In summary, the conversation discusses the use of a stepper motor and gearbox to achieve small, precise movements for a project involving a crystal on a platform. The gear ratio needed for microradian steps is determined to be 125:1, and the holding torque of the chosen motor is 7.5 oz-in with a detent torque of 0.5 oz-in. Questions are raised about the torque lost in the microstepping and gearing process, whether the remaining torque is enough to overcome the detent, how to calculate these values, and if there is a better method for achieving small steps. Further research is recommended to gain a better understanding of high precision motion systems and turntable stages.
SquidPhysics
So for my current project, I need to hold a crystal on a platform that needs to turn on the scale of microradians. I'm accomplishing this with a 1.8 degree/full step stepper motor that I'll be microstepping by 1/256 full step. To get to microradians, I'll need an additional division of steps that I'll be achieving with a gearbox. I'm fairly certain that to get 1 microradian steps, the gear ratio needs to be 125:1. The holding torque of the motor I'm considering is 7.5 oz-in with a detent torque of 0.5 oz-in. The platform and crystal weights should be less than 7.5 oz and will be further designed later. The experiment is kept at about 6E-6 torr in a vacuum chamber. To clarify, the motor only needs to make very small, very accurate movements and won't be used for full rotations. I've done more research into this than I can stand for a day so the questions I'm left with are:
1) how much driving torque am I losing to the microstepping process and the gearing?
2) Is the torque I'm left with enough to overcome the detent?
3) How do I calculate these things myself? I've not found much helpful info regarding this question.
4) Is there a better way to go about achieving these very small steps? The gear ratio is a bit troubling.

The proposed system will not give you anywhere near the accuracy required .

There is a large amount of information about how high precision motion systems are designed available on the internet .

High resolution turntable stages are commercially available .

Do some research and please come back if you have specific questions .

Last edited:
Just for info... Gearing down reduces rpm but multiplies the available torque. So a high ratio reduction gearbox can magnify the torque of a motor enormously. But see Nidum's reply.

## What is microstepping and how does it work?

Microstepping is a technique used in stepper motors to divide each full step into smaller steps, resulting in smoother and more precise movements. It works by controlling the current sent to each motor coil, causing the motor to move in smaller increments instead of the traditional full step movement.

## How does gearing affect the torque of a motor?

Gearing is the process of connecting two or more gears in order to transmit power and motion. In motors, gearing can affect the torque by either increasing or decreasing it depending on the gear ratio. A higher gear ratio will result in a lower torque output, while a lower gear ratio will result in a higher torque output.

## What are the advantages of using microstepping in motors?

The main advantage of using microstepping in motors is the smooth and precise movement it provides. This is especially useful in applications that require precision and accuracy, such as 3D printing or CNC machines. Microstepping also reduces motor noise and vibration, resulting in a quieter operation.

## Can microstepping be used with all types of motors?

Microstepping can be used with stepper motors, which are commonly used in applications that require precise positioning. It is not typically used with other types of motors, such as servo motors, as they use a different control system and do not require microstepping for smooth movement.

## How do I determine the appropriate microstepping and gear ratio for my application?

The appropriate microstepping and gear ratio will depend on the specific requirements of your application, such as the desired precision and torque. It is important to consult the motor's specifications and to consider the load and speed requirements when selecting the appropriate microstepping and gear ratio for optimal performance.

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