matching molds with materials

When going "cheap" be sure to specify standard and not metric. I want standard threads in the eyebolt holes and I want standard nozzle radius in the sprue bushing. NO METRIC STUFF. That will just cause delays in what is most likely an already late project.

Putting in a hot manifold system when it isn't financially justified.

Not having a processing savvy representative at mold trials. If you use the same mold builders a lot, teach them how you want them to sample the molds. Have them document their test parameters. Anyone can just squirt some plastic.

Gate size/type depending on the resin! I get those darn sub-gates on ABS/PC, cosmetic critical parts, and they complain about gate blush! Or knit line placement. Or drop sizing too small for the delivery volumes/pressure loss. Not all about the resin type, but they happen too often in this day and age! Rick.

Here are some starters

Most common mistakes when specifying a mold for a material:

1. Shrinkage specification

2. Going ‘cheap’ on the mold

3. Over/under specifying cavity count

4. Running the mold first and then putting in the vents

5. Letting the sprue/runner control the cycle

6. Residence time / shot capacity for mold/machine

7. ‘pushing the envelope’ for flow length of the material

8. Not having an agreed upon definition of an acceptable part.