Tips for Designing FDM Composite Tooling

Regardless of the general FDM tool style you are using, designers should strive to minimize material use while optimizing print time and quality for the desired application. The following are general tips for cost-effective design of FDM.

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  1. Step 1:

    1. Print the least amount of material possible. (Obviously)

    Design the tool for the intended use. Repair and development tooling often times do not require the robust construction that production tooling requires.

    Design from the composite laminate rather than an existing tool. This helps to reduce excessive bagging area. Typically, FDM tooling only requires 2-3” beyond the EOP for bagging materials.

    Shell-style tool designs typically help to minimize material use over sparse style tooling, especially when envelope bagging.

    When using edge bagging sparse style tools, printing with open ends and large air gaps, up to 2”, can reduce material use and improve air flow during the cure cycle, Figure 2.

  2. Step 2:

    2. Use self-supporting angles to minimize the amount of support material required, Figure 3. Overhanging features require support material, which significantly extends build times while also increasing material use.

  3. Step 3:

    3. Orient the tool such that the layup surface is printed in a vertical orientation and requires the least amount of support material, Figures 3-5. The vertical orientation typically produces the best surface finish by minimizing stair-stepping. This maximizes surface quality and minimizing post processing work.

  4. Step 4:

     4. Utilize larger layer thicknesses, aka – slice heights (0.013 and 0.020 inch). Larger slice heights dramatically reduce print time and allow for less dense support structures in sparse style tool designs. This can significantly reduce cost with very little impact on finishing work (depending on build orientation – refer to tip 3 above).

  5. Step 5:

    5.  Avoid ultra-fine features such as scribe lines and rosettes. These features, typically just 0.005 inch in depth, do not print reliably even at the finer slice heights. Alternatively, a secondary trim tool can be designed and utilized for post-processing operations.

  6. Step 6: Summary

    These are just a few of the main design tips that can help optimize FDM composite tooling.