Optics alignment error prediction

Solidworks Simulation A prediction of an optical assembly alignment error

03/22/2016

Don Blanchet

3B Associates

Problem

Optical sensor assemblies have been shipped to customers with defects. Screws without loctite thread lock.

Loose screws were found in the shipping container of some top assemblies.

All units have been deployed.

There have been no reported optical errors.

Estimate the potential axis alignment error to establish a recall schedule.

Precision machined Assembly

lens

Precision machined Assembly

lens

Alignment Axis

Center line of lens

FEA mesh - 450,000 d.o.f. Maximum

10g Acceleration load

Result –max gap at missing screw location = .0025 inches

lens

Alignment Axis

Center line of lens

Result optical axis deviation - .0044 inches

Conclusion

The single missing screw will add to the optical misalignment budget.

At the peak of the worst case load of 10G an additional alignment error of .0044 inches is predicted.

Conclusions