At MSINC, we see it EVERY DAY! It doesn’t matter if you are a corporate automotive design engineer or a person starting a new business with a great invention; designing plastic parts to keep tooling costs down instead of designing your parts with a focus on keeping part costs down and quality is the “perfect storm” for your long term success!
Lets face the ugly truth. Launching new products into the marketplace requires a significant amount of “up front” capital money and everyone wants, and needs, to get the most return (bang) for their capital investment dollar (buck). Competition is fierce. Material and production costs always go up….not down. And even if you have a great product with little competition, you are still competing for consumer sales dollars that are not easy to get and keep for the long term.
“Tooling side actions like slides or cores are just too expensive”….WRONG! Too expensive compared to what? It is true that a “no action” mold will be cheaper than a mold with slides or lifters, BUT, in many cases adding features to your parts that require side actions can reduce the actual number of additional components needed in total product assemblies. Therefore, a financially responsible part design may require a slightly more expensive mold for itself, but completely eliminate the need for several additional molds!
“My part design doesn’t require slides so why are you quoting it with slides?”….because it will not run consistently, efficiently and defect free without slides! I see this ALL THE TIME on parts that are very deep and/or have ribs and require long ejection strokes. If your part needs to be molded deeper than about 1″-1.5” deep on the core side of the mold, you may need slides on the outside of the part to release the part effectively during part ejection. You have to understand that lower part pricing depends on robust, problem free molding cycle times! Deep parts that want to stick in the core require ultra slow part ejection to keep ejector pins from pushing through or making un-sightly pin marks and sometimes slow ejection still isn’t enough. In order to help those parts eject smoothly and freely without slow cycle times and quality problems, those parts may require simple short travel slides on the outside of the part. BEWARE OF THE MOLD MAKER that says “the part is going to shrink to the core and away from the outside anyway”. Those guys obviously haven’t had to dig stuck plastic out of deep ribs in a mold that is already mounted in a molding machine