Set screws for pullys

Can someone give me the size of the set screws for the belt pully for the lead screw ??

The ones on the Shapeoko are 3mm. If yours are the same on the XCarve (they probably are) and have lost one, see if you can replace it with a 3mm cap screw as set screws that small are hard to tighten, easy to strip and as a result they don’t hold very well. Many have done this on their Shapeoko, I even changed some to 4mm which is even better.