Here at Premitec UK we can provide you with Pneumatic Die Lifters with either rollers or balls.
Die Lifters with rollers transport the tool or die in a straight line along the length of the rollers. (The length of the T slot).
Due to the large diameter and the one directional movement the amount of push/pull force required is approximately a maximum of 3,500kg per operator. A powerful die setter may be able to comfortably pull/push larger tools when loading or unloading using the die lifters with rollers.
Die Lifters employing balls are able to move the tool or die multi directionally. (forwards, backwards, left and right). However, the amount of push/pull force by the setter is greatly increased, due to the smaller diameter of the balls and the natural movement away from the line of operator directional force when loading. Once the tool is located in the press. it is then very difficult to align the tool left and right due to the operator having to stretch into the press envelope. With large tools over 4 tons, this is nearly impossible.
It has become more common for more engineers to choose the die lifters with rollers. Aligning the tool outside the press, then pushing the tool into the press bed envelope is far easier than using balls and struggling with levers and jemmy bars once it is in the centre of the press bed. And, they are a lower price..!