The last thing to be done in the injection mold making process is always the mold assembly, but all too often there is no checklist or method to the madness. Think about it, EDM has it’s method, CNC milling follows a structure, but the assembly.
The cores and cavities are done to perfection, the mold base has been constructed by a reputable supplier and all the dimensions are correct. All the injection mold components are on hand, and the only thing remaining is the mold assembly. This is crunch time.
It is highly recommended that an experienced injection mold maker does the actual assembly or at least closely oversees the process. Far too much hard work has gone into the mold to leave anything to chance at this point.
Have an experienced injection mold maker do the assembly
The experienced toolmaker must then have the judgment to determine what needs grooming, what can be left alone, which details are important, which ones are irrelevant. and so on. This skill can only be gained by experience.
Very often, the mold assembly is done in haste because the project is overdue, which is a formula for disaster. Another common problem is leaving the job half-finished for somebody else to complete. It is hard to communicate even simple details in the mold making process, much less just assuming that the next guy can figure out what is done and what needs to be done.
Be wary of passing on the job
Suppose that the first shift assembles the mold 60% and leaves the other 40% for the second shift. Even with the best of communication skills (which is very rarely the case), a great deal is left unspoken and taken for granted.
Larger molds have many, many components and all of them have a specific purpose and position. If one is out of location it could be disastrous for the job. What is readily apparent for the first shift might not even enter the mind of the person on second shift.
This is why it is much better to have one or two people responsible for the assembly: from beginning to end. The chance for error is just too great to pass the job on from one shift to the next. Obviously, there are exceptions.
Project managers have, at times, tried to write an assembly procedure manual for various jobs. This is an exercise in futility. It is nearly impossible to explain how to assemble an injection mold, and even more impossible to follow the directions!
One solution is to have the lead mold maker for the job be responsible for the assembly. If there is no one lead man, then one must be assigned. Once somebody has become intimately familiar with the job, he is more or less married to it. He may be able to pass on the information to another mold maker, but it is the experience that qualifies him for the task.