I recently brought the above and would like to convert this machine to CNC. I have read a couple of excellent build logs that Tweaky and Robin Hewitt have written. My question is regarding the diameter of the ball screws to use. The machine currently has a 24 mm dia for the x and y lead screws. As Robin found out there is a tight fit between the underside of the table and the base on the cross slide for the ball nut housing. I would like to use a 25 mm dia screw as this is close to the current lead screw. The two sizes of ball nut, 20 mm and 25 mm, have a dimension of 44 mm across the double 'D' and 48 mm respectively. I have measured my machine and the distance between the base on the cross slide and the majority of the table is 44 mm. The two ends of the table are closer and would need to be machined away to give the whole table the same clearance. If I were to machine a pocket where the base is on the cross slide to a depth of 5 mm from the original top of the base I should have room for either size ball screw. I am just not sure if a 20 mm ball screw would be OK. The table on this machine is 800 mm long. I would be interested in your thoughts.
Has anyone had any experience with ball screws from Marchant Dice Ltd?
Thank you in advance