Ball Replacing - HIWIN Linear Guide

How to replace balls?

This instructable is based on HIWIN EGH15 CA linear guide. Its simple process but you need some tools and very much patience. Ball replacing is a time consuming task. You need to be accurate!

There are three steps:

First, check dimensions of old balls! Its very important step. You should check a lot of old balls and then compare dimensions of old balls with standard catalogue of balls.

For example, in my case, old balls have an dimensions between 2,66mm and 2,73mm. After visit in my local store next standard dimension of balls is 2,778mm. You should choose the best quality of balls (the best accuracy class of balls).

Second, count amount of balls in your linear guide. In some cases (because of wear and tear), there are some difference between two side (some balls are missing).

For example, if on the left side you have 10 balls but on the right side you have 20 balls, you should buy 40 balls or more!

Third, put new balls to linear guide.

ps. sorry for my bad English.

Step 1: Tools Needed

Below is a list of tools:

- screwdriver,

- caliper (good quality) or micrometer,

- pliers,

- tweezers,

- Grease for bearings or linear guide and of course new balls.

Step 2: Check Old Balls and Replace Them

At first, you should unscrew red cover. There are two screws. If you have grease fitting, you should unscrew it too.

After that, move out red cover. There are two next screws. Unscrew it and move out green plastic. Now, you have a access to all balls.

Check of dimensions of balls, count them and go to store. Buy new balls and replace them - on all rails, there should be the same amount of balls.

If you put too much balls, you will get some tension on rail. But maybe you need this tension.

Step 3: Put Together All Parts

After replacing of all balls, you can, finally, put all parts together. Be careful - there is a Red slider. This slider should be mounted properly. See pictures - first is wrong mounted, second one is correct.

Step 4: Final Test of Linear Guide

Put linear guide on the rail and test them. there should be no clearance. Also linear guide should move on the rail without any resist. You should use grease before use linear guide.