I often see many people getting hung up on the specific percentage fill for first stage short shots…
In a 4 cavity mold, I usually have to make the part 90% full to create a short shot in all cavities. Is that OK, or does it have to be exactly 95% full?
It is more important to have a short shot in each cavity than it is to have the mold 95% full. Personally, I am less concerned about the percentage being 90 or 95% than I am about the cavities being short shot. If you have a short shot in each cavity, then you can properly compensate for variation during fill. If you are already full during 1st stage, then you have no buffer for variation, and are likely to encounter shorts and flash over the course of your run.
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