Composite Molds

Canuck Engineering provides design and manufacturing services for a variety of female CNC or composite molds.

Mold projects are typically complex and quoted price will reflect complexity, desired materials, CNC machine time, and labour required.

Typical approaches:

  • CNC female aluminum, Renshape, hardwood, or dense foam molds.
  • Male masters from Epoxy soaked MDF, hardwood, fiberglass over foam are created first.  Wet layup epoxy molds are hand created from the masters.

Approach chosen will depend on project goals, schedule, and budget. 

Machining masters will allow multiple production molds to be manufactured without the extra machine time or high cost of raw mold materials needed for multiple CNC female molds.  Also additional time is needed to produce masters first and then molds.

Cost Factors to Consider

  • Raw Material Costs
    • Renshape $$$$ (Urethane tooling board)
    • Cast Plate Aluminum $$$
    • Hardwood $$
    • High Density Foam $$
    • Pro Set Laminating Epoxy $$
    • MDF $
  • Labor ($30/hr)
    • Epoxy Soaked MDF masters require extra finishing work before molds can be layed up.
    • Mold/Master hand finish/polish is labor intensive.
    • Example:  Epoxy soaked MDF has cheap materials cost and cuts fast but requires 2 CNC finishing passes (one before soak and one after) and several hours labor for raw blank assembly, epoxy soaking, painting, and finishing.
  • Machine Time (Cost is $50/hr)
    • Materials (Typical Inches Per Minute Cutting Speeds)
      • MDF – 250IPM
      • Renshape – 250IPM
      • Hardwood – 200IPM
      • AL – 30IPM
    • Bigger step overs greatly reduce machine time but increase surface roughness that will need additional hand finishing work.
  • CAD/CAM ($50/hr)
    • Complex designs take more machine time, CAD and CAM work.
    • Incomplete or poor CAD models will require additional work before design is ready for CAM.

Typical Quote Example:

Wing molds for a 60″ UAV model.

  • Epoxy soaked MDF Masters (4 panels, Left Top, Left Bottom, Right Top, Right Bottom)
    • 5hrs CAD/CAM Design (5hrs @ $50/hr)
    • 20hrs machine time per panel (80hrs @ $50/hr )
    • 10hrs Master finishing and painting labor per panel (40hrs @ $30/hr)
    • 20hrs labor per female wet layup panel mold. (80hrs @ $30/hr)
    • Materials
      • MDF 1 Sheet @ $35
      • Epoxy Masters 1/2 Gallon @ $200/Gallon
      • Epoxy Molds 3 Gallons @ $200/Gallon
      • Molds – Fiberglass Cloth Approx $100
      • Masters – Primer and Clearcoat Paint Approx. $100
    • Total $7850 labor and machine time plus $935 materials
    • Project Completion Time:  6 – 8  weeks

Notes:

  • CNC machine is limited to 2′ x 6′ x 5.5″ cutting area.  Larger molds will need to be designed and cut in sections.
  • Cutting Aluminum is painfully slow compared to other materials.  Also polishing AL mold surfaces is very labor intensive.  AL cast plate cost approx. $8/lb.  Large AL molds are very heavy!
  • MDF is heavy weighing approx. 100lbs per 3/4″ 4×8 sheet.  Large masters made from MDF will be very heavy!
  • Renshape is available in several sizes and densities.  It CNC cuts easily and can be directly polished.  Material cost is higher than AL but labor is significantly lower.  Mold durability is somewhat lower than AL.
  • Composite wet layup molds are generally less accurate than direct cut female molds due to the master finishing steps.  Large wet layup molds do have some flex and will need additional support or back fill material.
  • CAD/CAM is completed in Fusion 360 or Rhino 5.0.
Example Link