There are some guidelines as below to place ejector pins on mold design.
1. Ejector pin location
1.1 The distance pin to the edge of the plastic part should be 0.04~0.10 inch.
1.2 To place the pin to bottom of part as A pin, and leave 0.01inch to the edge of core. Not good to place as B pin on top of part.
1.3 The locations as picture below, A better than B, B better than C.
If there is no choice, have to place pin at C location, then it’s better to add some small step on pin to increase the ejection force.
1.4 If must place pin on A location without better option.
1.4.1 Must make the pin lower the parting line 0.0005 inch, same as venting depth.
1.42 Add spring under the return pins to protect the ejector pin.
2. Pin fitting length and clearance.
3. Ejector pins should be locked if the pins placed on the non-flat surfaces of part.
