Reducing 3D Printing Costs
One of the most common questions we get at Brainchild is: “Why is this part so expensive?” Often, the answer isn’t the material or the machine time—it’s the geometry.
Design for Additive Manufacturing (DfAM) is different from designing for CNC or injection moulding. If you design a part as if it were a solid block of aluminium, you are paying for wasted material and unnecessary support structures. By making five simple tweaks to your CAD files in Rhino, AutoCAD, or Fusion 360, you can drastically Reduce 3D Printing Costs while actually making your parts stronger.
1. The 45-Degree Rule (Kill the Supports)
Support material is the enemy of efficiency. It adds print time, wastes material, and leaves a rough surface finish that requires manual labor to clean.
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The Rule: most industrial FDM printers can print angles up to 45 degrees without support.
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The Fix: If you have an overhang, don’t make it 90 degrees. Chamfer it to 45 degrees. This makes the part self-supporting and eliminates the need for scaffolding.
2. Chamfers are Better than Fillets
In machining, fillets (rounded edges) are great because they match the round rotating tool. In 3D printing, fillets can be a headache, especially on the bottom face touching the print bed.
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The Problem: A curve on the bottom edge creates a severe overhang that curls up or looks messy.
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The Fix: Use a Chamfer (a flat angled edge). It looks professional, reduces stress concentrations, and prints perfectly without support.
3. Don’t Print Threads—Use Inserts
We often see clients modelling M3 or M4 threads directly into their plastic parts.
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The Reality: 3D printed threads are weak. They strip easily after a few uses, meaning the whole part has to be scrapped.
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The Solution: Design a slightly larger plain hole and use Heat Set Inserts. These are brass threads that we melt into the plastic post-print. They are cheaper in the long run because they allow the part to be assembled and disassembled hundreds of times without failure.
4. Hollowing and Shells
If you send us a solid block, the slicer software calculates the volume based on the infill settings. However, you can save money by designing the wall thickness yourself.
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The Fix: Instead of a thick solid block, use ribs or honeycomb patterns in your CAD design to maintain stiffness while removing mass. Less volume = less material = lower cost.
5. Flat Bottoms for Bed Adhesion
A 3D printer builds from the ground up. If your part is a complex organic shape (like a sphere), it has a tiny contact point with the bed, requiring a massive “raft” of support material to hold it up.
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The Fix: “Cut” a flat face on the bottom of your design. Orienting the part to have the largest possible surface area touching the bed ensures a stable print and zero support waste.
The Bottom Line
A few minutes spent optimizing your CAD file can reduce 3D printing costs by 30-50%. You get your parts faster, and they perform better.
Not sure if your design is optimized? Send your file to us for a Design Review. We can suggest specific changes to get your project under budget.
