Infrared Optics Grinding Machine
Un infrared optics grinding machine for production small-aperture work — convex, concave, or flat on one spindle, on Ge, ZnSe, ZnS, Si or sapphire blanks up to Ø 100 mm, with form held to ±0.005 mm and centering inside 20″.
A compact spherical generator for small IR optics
PLC + servo control, mechanical centering with a centroscope optical-axis check, and one spindle that handles convex, concave, and flat surfaces without a tool change.
The G-100 infrared optics grinding machine is a compact spherical generator built on a cast-iron base for vibration stability — spindle vibration sits inside ±3 µm, which is what holds the form tolerance on a thin Ge lens. Control is PLC + servo with an English HMI and a handheld controller; that's deliberately not full CNC, because production spherical work doesn't need it and the simpler interface trains a new operator in a shift.
- Workpiece range Ø 10–100 mm · thickness ≤ 30 mm
- Positioning accuracy ±0.003 mm on each axis
- Spindle runout radial & axial within 0.005 mm
- Spindle vibration displacement ≤ ±3 µm
- Bearings NSK 7203C / 7005AC P4 mechanical bearings, natural air cooling
- Control PLC + servo · English HMI · handheld controller · backlash compensation N/A (servo direct)
What the G-100 infrared optics grinding machine does
A spherical generator built for production small-aperture IR lens work — not a CNC freeform machine, not a desktop lapper. The features below are what actually drives form, throughput, and yield on the shop floor.
Convex, concave & flat — one spindle
Same chuck handles all three surface types up to Ø 100 mm. No wheel change, no fixture swap — change the program, change the surface.
±0.005 mm form, ≤ 20″ centering
Surface form after grinding holds inside 0.005 mm; centering with the centroscope optical-axis check stays inside 20 arc-seconds — tight enough for athermalized thermal-imaging assemblies.
< 0.2 mm edge chipping
On germanium and ZnSe — both materials that punish the wrong wheel approach. The G-100's spindle stability (±3 µm vibration) and recommended electroplated wheel (350–400 grit) together keep chips inside the centering allowance.
~45 sec / face cycle, Ø 40 mm Ge
Typical face-grind on a Ø 40 mm germanium blank with 0.5 mm single-side allowance — fast enough that a small thermal-imaging line doesn't bottleneck at grinding.
PLC + servo, not full CNC
Deliberate. Production spherical grinding doesn't need a CNC license — the PLC + servo controller with English HMI trains a new operator in a shift and skips the licensing cost that buys nothing on spherical work.
Cast-iron base, ±3 µm spindle vibration
Vibration shows up as form error and edge chipping. The cast-iron base damps it, the precision NSK bearings hold radial / axial runout inside 0.005 mm, and natural air cooling keeps thermal drift out of the spindle housing.
See the G-100 grind a small IR lens
How the infrared optics grinding machine sets up — chuck the blank, dial in the centroscope, select the wheel angle for the target surface (convex / concave / flat), and run the cycle. Two clips below: one on the centering setup, one on a full grinding cycle.
▸ Setup — centroscope centering inside 20″
▸ Cycle — face grind on a germanium blank
Need a clip for your specific lens drawing? When you request a sample grind, we record the run on your blank and send it with the metrology report.
Why small-aperture IR grinding is a throughput problem first
For shops running an infrared optics grinding machine on thermal-imaging volume — Ø 20–60 mm Ge or ZnSe lenses for handheld scopes, automotive ADAS, or sensor modules — the cost driver isn't material price. The ingots and wafers are already cut. It's how many parts come off the grinder per shift, and how many of those parts are within spec on the first pass.
Two numbers set that. First, cycle time per face. A typical Ø 40 mm germanium lens with 0.5 mm single-side allowance grinds in 40–50 seconds on the G-100; double-sided that's about 90 seconds plus chucking. At 60% utilization across an 8-hour shift, a single G-100 puts out 200–300 lenses. Second, first-pass yield. The G-100 holds form within 0.005 mm and chipping under 0.2 mm; that's enough margin that the downstream centering and polishing stages don't reject material back upstream.
Where the G-100 infrared optics grinding machine earns its keep against a general-purpose CNC freeform grinder is the same place it earns it against an outsourced grinding service: spherical work doesn't need CNC freeform's feature set, and outsourcing trades cycle time for lead time. For the surface-finish theory and grinding-to-polishing handoff details, see our germanium lens grinding process page.
Spherical generation, plus the bits everyone forgets to spec
One spindle for three surface types
Tilt the wheel cup, change the program — the same chuck and spindle generate convex, concave, or flat surfaces on the same lens blank if you need both faces of a meniscus. The wheel itself is a 350–400 grit electroplated nickel-bond cup on a #45 steel base; we ship the G-100 with one wheel for each common grit, and a wheel change is under five minutes once the spindle is calibrated.
Centering before grinding, not after
The integrated centroscope is what makes the ≤ 20″ centering tolerance achievable. Drop the blank in the chuck, swing the centroscope into the optical path, dial the chuck until the optical axis pin sits steady on the reticle, lock it down. Now the spherical generation cycle has a true optical-axis reference, not a mechanical OD reference. Decenter on the finished part is bounded by how well you set the centroscope, not how round the blank's OD was.
The G-100 doesn't run backlash compensation in software, because the servo drives a direct ball screw without a gear backlash to compensate. New customers who ask for backlash compensation as a spec line are usually carrying it over from a stepper-driven machine. On servo-driven ball screws like this one, the relevant spec is repeatability (±0.003 mm here), not backlash. Worth flagging before the spec sheet comes back marked "no" and somebody worries.
How does a dedicated spherical grinder compare to CNC freeform and outsourcing?
Most small-aperture IR work is spherical or near-spherical. A dedicated infrared optics grinding machine like the G-100 handles that natively. A full CNC freeform grinder will do the job too, but it's optimized for aspherics and freeform optics — features you pay for and don't use. Outsourcing trades cycle time for lead time. Here's how the three approaches compare on a typical Ø 40 mm Ge production run.
| Approach | Cycle / face | Form tolerance | Setup & training | Lead time |
|---|---|---|---|---|
| Full CNC freeform grinder | 90–120 sec | tight (overkill) | CNC programmer needed | days |
| Outsourced grinding | n/a | varies by vendor | none (drawing handoff) | 2–6 weeks |
| G-100 dedicated spherical | 40–50 sec | Forme de ±0,005 mm | PLC + handheld, one shift | in-house |
The G-100 wins on cycle time on its native job (spherical, small-aperture IR) and loses to a CNC freeform machine if you also need aspherics on the same machine. That's a real tradeoff — if your product mix is 70% spherical and 30% aspheric, two G-100s plus a CNC freeform usually beats three CNC freeforms on both CapEx and shift output. Reference materials data is in Crystran's germanium datasheet; finished-lens tolerance frameworks are normes de dessin optique ISO 10110.
The G-100 will generate near-spherical surfaces with controlled departure, but a true aspheric — large sag, varying curvature — wants a CNC freeform spindle with closed-loop profile control. Honest answer: send us your asphere's drawing and we'll tell you whether the G-100 will do it or whether you want a different machine.
Built for production small-aperture IR work
Why the G-100 infrared optics grinding machine earns its place on a thermal-imaging line — the numbers that drive cycle time, yield, and the tolerance handoff to centering and polishing.
G-100 technical specifications
Standard-configuration specs for the G-100 infrared optics grinding machine. Each row is committed at the machine level — no carry-forward from a different model's datasheet.
| Workpiece diameter | Ø 10 – 100 mm |
| Workpiece thickness | ≤ 30 mm |
| Surface types | convex · concave · flat (same spindle) |
| Axis positioning accuracy | ±0.003 mm |
| Spindle radial / axial runout | within 0.005 mm |
| Spindle vibration (displacement) | ≤ ±3 µm |
| Surface form after grinding | within 0.005 mm |
| Centering tolerance (centroscope) | ≤ 20″ arc-seconds |
| Diameter tolerance | ±0,01 mm |
| Roundness | ≤ 0.01 mm |
| Edge chipping (Ge / ZnSe) | < 0.2 mm |
| Cycle / face (Ø 40 mm Ge, 0.5 mm side allowance) | ~40–50 sec |
| Cycle / face (Ø 80–100 mm) | ~70–80 sec |
| Recommended wheel | electroplated nickel-bond, 350–400 grit on #45 steel base |
| Liquide de refroidissement | water-soluble emulsion |
| Bearings | NSK 7203C / 7005AC P4 — mechanical, natural air-cooled |
| Linear guides | 4-direction equal-load preload precision rail |
| Ball screws | single-nut un-flanged rolled C7 preload |
| Control | PLC + servo · English HMI · handheld controller |
| Drawing standard | normes de dessin optique ISO 10110 |
| Service life (well-maintained, clean environment) | 20–30 years |
Tolerances on the ground part flow into the centering machine and the polisher per normes de dessin optique ISO 10110. The form-error budget left at this stage is what gives the polisher its removal target.
Which IR materials does the G-100 grind?
The brittle IR materials that show up most often on small-aperture thermal-imaging and CO₂-laser optics. Each gets its own wheel grit and coolant cadence — the G-100 ships with parameter sets for the common ones, and we calibrate new sets on customer-supplied blanks:
- Germanium (Ge) — Mohs 6–6.5, cleaves on {111}; 350–400 grit wheel, gentle infeed
- Zinc selenide (ZnSe) — softer Mohs 4–4.5, easy to chip; light contact, fresh slurry
- Zinc sulfide (ZnS) — multispectral and clear grades; similar approach to ZnSe
- Silicon (Si) — mature spherical grinding parameter set
- Saphir — slower removal but stable, scratch-resistant final surface
- BK7 / K9 optical glass — reference workflow if you need a quick wheel check
For deep-dive ZnSe / ZnS grinding chemistry — wheel-grit tradeoffs, coolant pH, edge-chipping control on the {110} cleavage — see our dedicated ZnSe / ZnS optics grinding machine page.
Where it fits in an IR lens line
The G-100 infrared optics grinding machine sits between the cutting station and the polisher. It takes a sliced lens blank — typically off an endless-wire saw — and hands the polisher a ground surface with form inside 0.005 mm and SSD shallow enough that polishing time is bounded. Centering happens here too, with the centroscope check before each grinding cycle.
Looking at the whole chain rather than just the grinding stage? The germanium lens manufacturing solution page lays out the five-stage workflow from ingot to coated lens. The upstream pairing here is usually the germanium wafer slicing machine; the full equipment range is at the équipement de fabrication d'optique infrarouge hub.
For larger lenses — beamsplitters, large-aperture defense optics, anything beyond Ø 100 mm — the G-100 is the wrong frame. The G-250 grinder covers Ø 80–250 mm with the same spherical-generation principles. For deep-dive ZnSe / ZnS material chemistry on either machine, that same page is the engineering reference. And if you genuinely need aspheric or freeform optics, a full-CNC machine fits the job better than either G-series spherical generator.
Get a sample grind on your own blank
Pick the G-100 infrared optics grinding machine if you're running small-aperture spherical IR work — thermal-imaging modules, sensor optics, ADAS lenses — and you want a dedicated spherical generator that doesn't bottleneck your line. Send us your finished-lens drawing and a sliced blank; we'll grind a proof part and return it with a metrology report before you commit.
Vimfun · ISO 9001 · CE compliant · shipped to 20+ countries
Optics customers include Edmund Optics and Coherent.
Tel +1 (408) 571-8651 · daria@endlesswiresaw.com