# Horizontal Linear Motion With Belt&Pulley – 1

**Guide, Belt Pulley , Reducer and Servo Motor Sizing**

Belt pulley driven is not my favorite method for linear motion. Because this is the drive method with the weakest positioning accuracy. However, if a cheap and high speed method is required, belt pulley is the most suitable method.

I’m using Yaskawa SigmaJunmaSize+ and THK Life Calculator applications for my all calculations.

Target values;

Max Speed: 1000mm/sec

Stroke : 2000mm

Let’s start by calculating linear guides as usual. This time we have an asymmetric gravity point. There is also a high speed request, which is specified as 1000 mm / second. Therefore, we will use the SHS series, which is more suitable for high speed. You can use these products either externally or assembled in a linear module.

##### Linear Guide Sizing

While choosing our linear guide, we increase it by starting from the smallest size and trying it in order.

The smallest model of the SHS series, SHS 15 type, seems to be sufficient for the requested values.

##### Servo Motor Sizing

When I enter the required values into the program, it is seen that the servo motor with a reduction ratio of 10 is suitable.

It doesn’t matter if the nominal speed is colored red. Since the motor’s operating range is between 1500rpm and 3000rpm, it will produce the speed and power we want.Remember that I have mentioned in the previous posts regarding coupling, pulley and reducer inertia values. We will see the calculation of their inertia values in next posts.

As a result, the program gave SGMGV-09 high inertia servo motor for i:10 .

Acc : 10m/s2

Load: 200kg

Horizontal Force at Acc/Dcc

F=m*a

F=200*10

**F=2000N**

##### Belt Tensile Force Check

Now we’ll check the maximum allowable belt tension value.

For one belt the value is 1920N but we are going to use two belt line. So first we have to multiply the belt tensile strength by 2.

Ft=1920*2 = 3840N

3840N>2000N ✔ (in Safe)

###### Selection results;

Servo motor : SGMGV-09 ( 0,85 Kw high inertia )

Pulley : AT 10 Z: 32

Belt : AT 10 W:25mm

Linear Guide : THK SHS15 ( Narrow or Wide type )