Sandia Optical
Single Point Diamond Turning

SPDT for prototype optics and mold-insert finishing.

Diamond turning lives in the same building as the press floor, so the surface that proves a design also runs the program. Use it for prototypes before steel, low-volume freeform, and the optical inserts that decide how the molded part performs.

Diamond tool engaging a polymer substrate on an ultra-precision lathe spindle.
SPDT spindle — diamond tool engaging polymer substrate.
Machines & capabilities

Two SPDT platforms, sized for prototype and insert-finishing work.

SPDT platforms — representative specifications; per-program tolerances confirmed in scoping.

Machine / capability Specification
Moore Nanotech 350FG 4-axis ultra-precision lathe with freeform/toric and slow-tool-servo; prototypes, freeform surfaces, optical-insert generation
Nanotech 250UPL 2-axis revolution-symmetric; high-throughput blanks, mirror substrates, rotationally symmetric inserts
Maximum part envelope ⌀ 250 mm (350FG), ⌀ 150 mm (250UPL)
Maximum sag 25 mm
Environment Temperature- and vibration-controlled SPDT bay, separate from molding floor
Materials

Polymer and metal substrates the SPDT bay sees regularly.

  • PMMA
  • PC
  • COP / COC
  • Polystyrene
  • Electroless nickel (mold-insert finishing)
  • 6061 aluminum
  • Brass
  • OFHC copper
Surface finish & form

Typical achievable — on the right material and geometry.

Surface roughness and form-error envelope by material (best-case; measured per part)

Material Surface roughness (Ra) Form error envelope
PMMA < 5 nm < 1 µm PV across a 50 mm aperture on best-case parts
PC < 8 nm < 1.5 µm PV at full envelope
Electroless nickel (insert finishing) < 10 nm < 250 nm PV on small-aperture inserts
COP / COC, PS, 6061 aluminum, brass, OFHC copper Tracked per program Tracked per program

Every part is measured on the interferometer or profilometer; a per-part metrology report is available on request and is part of the release evidence when a customer's program requires it.

When SPDT is the right answer

The five places programs reach for the lathe instead of the press.

Prototype before tooling
The fastest path from prescription to optical evidence on a real surface — without committing tool steel.
Low-volume freeform
Programs where ramping a mold is the wrong economics; SPDT replaces the cavity for low to mid volumes.
Mold-insert finishing
Optical inserts cut and polished in our SPDT bay, then handed straight to our injection-molding floor.
Mirror substrates
Electroless-nickel mirror blanks and figured aluminum substrates for reflective optics and pickoff mirrors.
Wavefront-class parts where ramp economics fail
Defense and aerospace programs that need an optical surface but cannot justify mold ramp — we run SPDT to net shape.

Bring us the prescription and the volume profile.

We will tell you whether the right move is SPDT to net shape, an SPDT insert into the press floor, or a hybrid path through both.

Discuss an SPDT prototype