Award Winning Twin-Sheet Formed Pin Setting System
ATI made these two parts utilizing our Technical Twin-sheet process, which molds geometric features on both sides. This part is constructed from two panels, both Front and Rear. The assembly, shown in top view from the pin-setter side (facing the bowler) is comprised of two Technical Twin-sheet parts. We mechanically attach these parts to each other, thus creating a chain guide recess between the two parts. The chain is a portion of what is shown in View #2. Of interest, this chain has special cups on it to capture the pins and lift them to the top Orientor Pan, View #4. At this time, the pins are oriented to be bottom down for placement in the actual pin-setting device. You can see the drive mechanism for the chain in View #3.
View #1 shows the entire assembly viewed from the Rear, as seen by the maintenance technicians. Additionally, we textured the surface of the Rear Panel in the molding process. This rear panel is really the only visible surface in the system. View #6 shows the inside of the Front Panel and the features that create one half of the chain track. To see a full perspective of the Chain Track see Views #8 & #9 below. We show in View #5 a slightly different perspective of this area, illustrating the 3D nature of the part. In View #7 we show several other parts made in the Technical Twin-sheet process using the same molds. These parts are also part of the total assembly. Importantly, we utilize these parts to help channel the pins to the pick-up zone for the chain.
Thermoforming Tooling Process Offers Benefits
Development of the functionality of the parts took us several years. One of the benefits we offer with the thermoforming tooling process is the ability to accommodate change. We underwent several significant iterations of geometry modifications while designing these parts. Due to our tooling process, we were easily able to accommodate these changes without scrapping the molds and starting over.
The material we selected for this project is Spartech’s Extreme TPO. This material is a polypropylene based polymer developed for its toughness and its extreme low co-efficiency of thermal expansion.
Solutions to CNC Challenges
We experience many hurdles in the twin-sheet process, insofar as geometry is affected by mold shrink. In much the same manner, the same shrink variables create challenges for us in the CNC trimming process as well. Always looking for innovative solutions, we developed an approach that helped solve this problem. We determined that by always centering the trimming of the part for the trimmed features the variability in overall size would not affect the ability of the two parts to go together.