SIMPLE LIFTER

Lifters are used primarily for relieving internal undercuts or for zero draft internal faces. Their motion is driven by the molding press pushing on the ejector plates. A simple lifter withdraws at 90 degrees to the line of draw, simultaneous with ejection. The angle of the lifter passing through the core frequently confuses the novice into thinking that it pulls the feature at an angle. Relative to the core the lifter indeed moves at an angle. Relative to the part however a lifter moves directly sideways because the part is being ejected forward at the same rate as the lifter. Note also that the lifter moves at 90 degrees relative to the ejector plates as the lifter foot slides along its gib.