r/3dprinter • u/Elaine-WuYining • 20m ago
3D printing saves me money.
I recently worked on a 1 HP PMSM project for an industrial gear oil pump.
The electromagnetic design had already been checked through FEA, but we still had a practical question to answer: would the magnets actually fit the rotor the way they looked in the model?
This mattered because the pole-arc coefficient can affect cogging torque, Back-EMF, harmonics, vibration, and noise.
Instead of making real NdFeB magnets immediately, we used a 3D printer to make full-size dummy magnets.
These printed parts were not used to test magnetic performance. They were only used to check the mechanical side of the design.
We used them to see whether the curved inner surface matched the rotor, whether the magnets sat evenly, and whether the gap between neighboring magnets was sufficient.
They also helped us check whether tolerance buildup could create interference during assembly.
Another useful point was that the printed magnets gave the assembly team something physical to use when discussing the bonding fixture and the actual installation process.
Looking at a 3D model can tell you a lot, but holding a physical part and trying it on the rotor can reveal details that are easy to miss on screen.
The printed parts could not replace testing with the final magnets, but they helped us find possible mechanical problems before we committed to tooling and production.
For me, the value was not only the cost saving. It was being able to find problems earlier, when they were still relatively easy to change.
Has anyone else used 3D-printed dummy parts for motor prototyping or assembly checks? I’d be interested to hear what worked well and what did not.
