hello community.

I have found out that there are screws for the CNC with balls which allow the nut to have no play, to give the CNC more precision.

I have a CNC3018 PRO (https://aliexpress.com/item/4001097302113.html).

The idea is to change the screws for ball screws to give it greater precision, it turns out that there are an infinity of these screws and since I am new to this world of CNC I do not understand the difference much.

I need a screw that is compatible with my machine, I measured the screws it already has and the measurements are as follows.

Length
40cm x
30cm and
10cm z

8mm (diameter)

My idea is to buy it through one of these sales pages like aliexpress, alibaba, ebay, amazon, etc. I would like you to guide me on what type of screw will work for a CNC3018 PRO, I am trying to find the best quality and low price, some material that is better than another.

The models I have seen are SFU and SFK