Replacement for THK GSR20T LM Block and rails

[Langdon]

I am repairing a 30 year-old CNC machine.

It is a 3-axis XYZ CNCX router.

It uses THK GSR20T LM guides and rails on all axes.

The X axis and the Y axis work great.

However, I only have 1 working LM guide for the Z-axis (2 are broken, 1 mysteriously disappeared).


I really don't want to buy 3 THK LM blocks, they are absurdly expensive.

The Z-axis does not have to be quite as strong as the other axes.

Would it be make sense to just buy new Chinese rails and LM guides and just sell the existing rails and LM block (plus the broken LM blocks)?

Are there any LM blocks that use M5 screws and have the same screw layout?

The rails also need to work with the existing anchor holes, which are also M5.

Thanks!

[thm_w]

GSR20T blocks are $40-60 on ebay, is that too expensive?

You can look up the drawings and find the dimensions and compare them: https://tech.thk.com/en/products/pdfs/en_a01_290.pdf