Horizontal Linear Motion With Rack&Pinion – 1

Guide, Rack&Pinion , Reducer and Servo Motor Sizing

Next is the calculation of the system that will be driven by rack and pinion. Usually this drive system is used in marble, wood, laser cutting and plasma machines.

Also I’m still using Yaskawa SigmaJunmaSize + and THK Life Calculator applications.

Target values;

Max Speed: 500mm/sec

Stroke : 2000mm

linear system steps chart We’ll start with linear guide sizing again.

Linear Guide Sizing

Based on my experience, I anticipate that the HSR25L type guide will be suitable for this job.

As you know we are trying to be close to 10 for safety factor.

linear guide sizing results

We see in the results that the HSR25L type guide is the right product.

Servo Motor Sizing

Let’s move on to the servo selection tool. You will see that I wrote 5,10 and 12 for the reduction ratio in the servo selection tool. For now, I am not showing the selection for which gearbox size should be. In the next posts we will see how the selection is made.

As I mentioned in my previous article, the inertia value of the coupling and reducer must be learned from the catalog. Pinion inertia value can also be calculated from the program. For now, I am writing values close to the value that should be. The value we need to know for the calculation is the diameter of the pinion. You can learn this as I showed in the catalog. The pinion I have chosen is generally the most used module 2 series.

I also showed you the details about how to choose some options of the servo motor selected in the video.

servo motor sizing results

As a result, the program offers us a servo motor from the SGMGV series (high inertia), which is 0.85Kw and 1500rpm (nominal).

Rack and Pinion Force Check

Acc : 5m/s2

Load: 700kg

Horizontal Force at Acc/Dcc

Horizontal Force at Acc/Dcc




rack and pinion force check

7472N>3500N  ✔

Selection results;

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

Rack : Helical Module 2

Pinion : Helical Module 2 Z:30

Linear Guide : THK HSR25L ( Narrow or Wide type )

Leave a Comment