Can Do Toolmaker


CAM Flexibility a Key to Molding Tool Manufacturing Diversity

Midgard Plastics, Inc., has built a reputation for being able to take on almost any tooling and injection molding challenge to deliver molded parts and components that satisfy the customer’s quality, cost, and delivery expectations. Midgard has the flexibility to go from quite small to very large parts, maintaining close geometric tolerances and finishes. The work has to be precise, yet very productive to keep all aspects of the work in-house.

Midgard’s Tool Shop Supervisor, John Lesh, said, “We do all kinds of plastics including polysulfone and glass-filled nylons, and we have press sizes from 20 tons to 720 tons for both conventional injection and rotary over-molding applications. Projects range in size from speedometer needles to large autoclavable cages to protect expensive, rare strains of research animals. Among numerous items that fill out the mid-range of Midgard’s capabilities include: choir bell handles, crew racing megaphones, left- and right-handed toothbrushes, eyewear display racks, electronics housings, and over-molded bungee cord hooks made in a wide range of colors and sizes.”

Midgard designs the majority of tools it uses in SOLIDWORKS® and then seamlessly imports the model into Mastercam® to create the CNC programs for manufacturing them on two 3-axis high speed mills. The company has two licenses and Lesh and another toolmaker, Don Mood, write the manufacturing programs, set-up and operate the CNC equipment, and assemble the tools. He cited a number of features that allow them to handle the challenges presented by a wide variety of mold designs and keep up with tool manufacturing deadlines:

  • With Mastercam’s solids and surfacing capabilities, Midgard saves nearly a week’s worth of polishing on molds, like those for the animal cages, which require high finishes.
  • The toolmakers use Mastercam’s Verify feature to ascertain the accuracy and safety of cutting programs before putting a part on the machine.
  • Toolpaths incorporating Dynamic Motion technology are used frequently to reduce CNC machine cycles and reduce deflection when long tools are used to reach into deep mold cavities.
  • Lesh said the exceptional accuracy of these toolpaths is particularly important when large mold components must be machined continuously (frequently unattended) for periods up to 36 hours.

Lesh said his management takes a very aggressive ‘can do’ approach to quoting molding projects with unique manufacturing requirements. He indicated that he has no idea from one day to the next what unique tool manufacturing challenge will show up in his queue. But he is sure that one will, and that with Mastercam, Midgard’s toolmakers will be able to handle it.