microcutting

Comparison of micro-waterjet, laser, EDM, NC, ... cutting

micro-waterjet

[MicroMAX at OMAX Demo Lab - https://www.omax.com/omax-waterjet/micromax]

Nozzle: 7/15 MAXJET5 Minijet Nozzle with 0.007" ID diamond orifice and 0.015" Roctec 500 mixing tube

Abrasive: 240 mesh Barton HPX garnet with a mean particle size of 60 um at a flow rate of 0.12 lb/min

Pressure: 50 ~ 55 ksi

Cutting time: 3.1 min

solid-state laser micromachining

ultrafast laser micromachining

EDM

Full-scale Toolpathing

We toolpathed the microspline part at the full ~2" long scale. This would be cut from a stack of six sheets of 0.03125" thick brass layered on top of a 1/16" thick piece of steel. We added slits in the frame to avoid pre-drilling any holes. We also removed all of the tabs. This may prove to be a bad idea but it allows us to get a sense of the speed of Wire-EDM vs uAWG without having to do a lot of pre-processing. The total path length of the full scale toolpath is 52.5 inches. With an expected cut speed of at most 0.22 inches/minute, the expected cut time is approximately 4 hours.

1/3-scale Testing

Given the long machining time, we ultimately decided to do a 1/3-scale test cut from a stack of 0.01" brass sandwiched between 0.25" aluminum. The perimeter of this toolpath measures 17.5 inches. With an expected cut speed of 0.18 inches/minute, the expected cut time is just about 100 minutes or 1 hr 40 mins.

NC

Fablight fiber laser

Machining time: ~5 min

Cost of machine: sheet only machine with the 3000 laser is around $80,000, and the tube & sheet is around $90,000

Machine settings:

Sample photos:

After burr removal

The brown seen on the edges of the piece are burn marks where the machine cut.

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