Optical Lens Grinding Machine
Nine generating machines, one decision. This page narrows an optical lens grinding machine down to one or two models in about three minutes — by how big the part is, how parts reach the spindle, and how much of the cycle the machine decides for itself. Specifications live on each model page; this page is for choosing.
Start from the workpiece, not from the machine list
Generating is the step that gives a sawn blank its first real geometry: a spherical radius, a cylindrical surface or a machined bore, left with a defined allowance for the polishing stage that follows. Everything upstream is still a block of material; everything downstream only refines what this step created.
That is why an optical lens grinding machine is specified from two directions at once — the blank arriving from the saw, and the surface the polishing cell expects to receive. A generator that is right for Ø12 mm sapphire in ten-thousand-piece batches is the wrong machine for a Ø110 mm germanium blank in lots of twenty, even though both jobs are called "generating".
Which loading method fits your production?
Every optical lens grinding machine in this range overlaps on radius and diameter. What does not overlap is how the part reaches the spindle. Read this table down the last column first — then check the diameter band.
| Model | Diameter | Curvature | Loading | Control | Choose it when |
|---|---|---|---|---|---|
| SG-80 | ≤ Ø80 mm | Swivel 0–45°, set by hand | Operator | Manual | Mixed short runs, prototypes, a first generator in the shop |
| SG-120 | ≤ Ø120 mm | Swivel 0–45°, set by hand | Operator | Manual | Parts too large for the Ø80 class — higher spindle power, internal-jet cooling, stiffer frame |
| Auto-SG-20V | Ø4–20 mm | R2 to flat | Vibratory bowl | Automatic cycle | Small lenses in bulk, arriving loose, thousands per batch |
| Auto-SG-80T | Ø10–80 mm | R5 to flat | X/Y trays, blank and finished in parallel | Automatic cycle | Parts that must stay in their tray, by batch and by order |
| Auto-SG-50VT | Ø6–50 mm | R5 to flat | Bowl in, X/Y tray out | Automatic cycle | Loose blanks in, ordered output for the next station |
| Auto-SG-50 Auto-SG-80C | Ø10–55 mm Ø5–80 mm | R5 to flat | X/Y modules | CNC, five-stage servo feed | Tight sagitta tolerance, long unattended runs, repeat orders |
| Auto-SG-20W | Ø5–20 mm | ±R2.5 to flat | Vibratory bowl, micrometer face sorting | Automatic cycle | Both faces of a small lens wanted in one pass, twin vertical spindles |
| CG-140 | X/Y travel 140 mm | Convex, concave and flat cylinders | Operator loads, cycle runs | CNC X/Y | Cylindrical optics — a different geometry, not a spherical machine |
| BG-50 | Machining range 50 mm | Round and slot bores, plus outer diameter and faces | X/Y/Z gantry from a cassette | Automatic cycle | Rings and windows with bores — 30,000 rpm electric spindle |
Diameter coverage, model by model
Eight spherical generators, drawn to one scale. An optical lens grinding machine is only a candidate if your part diameter sits inside its bar.
Solid bars are stated working ranges. Pale bars mark the two manual models, where the specification gives a maximum diameter but no minimum — the practical lower limit depends on the chuck and the fixture fitted to that optical lens grinding machine, and is confirmed with a trial part. CG-140 and BG-50 are not plotted: a cylinder is specified by axis travel and a bore by machining range, not by lens diameter.
Explore the machine families
One card per optical lens grinding machine: what it is for, and — just as useful — what it is not for. Specifications, assemblies and process detail are on the model pages.
SG-80
SG-120
Auto-SG-20V
Auto-SG-80T
Auto-SG-50VT
Auto-SG-50 · 80C
Auto-SG-20W
CG-140
BG-50
What does the CNC actually decide?
"CNC" on an optical lens grinding machine does not mean a screen instead of knobs. On this range it means four judgement calls move from the operator to the machine — which is the whole argument for the price difference.
It measures what it just cut
Sagitta is gauged in the cycle and the result corrects the next part automatically, instead of an operator reading a dial and nudging a stop.
It turns the part over
Face identification and flipping run inside the cycle, so both sides are generated in one loading rather than in two passes with a re-set in between.
It dresses its own wheel
Dressing interval and number of passes are set once. Wheel condition stops being the thing that quietly changes the surface over a shift.
It refuses to cut air
Vacuum detection confirms a part is actually present before the cycle starts — the difference between an unattended night shift and a tray of scrap.
Feed is split into five stages whose travel and speed are set independently, which is how an optical lens grinding machine can approach fast and still enter the cut gently on a brittle blank. The same logic is covered from the defect side in our note on subsurface damage in optical lenses.
Which materials and geometries are covered?
Every optical lens grinding machine in this step is built for hard, brittle optical materials. Where a specification sheet does not name a material, we prove it with a trial part rather than claim it.
| Material | Spherical | Cylindrical | Bores | Typical parts |
|---|---|---|---|---|
| Optical glass (crown, flint) | Yes | Yes | Yes | Lenses, windows, prism blanks |
| Sapphire | Yes | On request | Yes | Watch crystals, camera windows |
| Technical and optical ceramics | Yes | On request | Yes | Rings, seals, optical ceramics |
| Quartz and crystal | Yes | On request | Yes | Windows, crystal components |
Material behaviour under a diamond wheel is not a single number — hardness, cleavage and thermal conductivity all change the outcome. Published data for sapphire and crystal quartz is a reasonable starting point; the wheel specification and feed are then settled on real blanks.
Send a drawing and a few blanks of your own material. We run them on the machine under discussion and return the parts together with the process sheet — wheel, feed stages, cycle time. This applies across the generating range, not only to the machine you first ask about.
Cylinders and bores are not the spherical family
Three different surfaces, and an optical lens grinding machine is built around one of them. This is the most common mis-specification we see in enquiries.
- Spherical surfaces come from the angle between the wheel and the work spindle — set the angle, get the radius, with 0° producing a flat. Seven of the nine machines work this way.
- Cylindrical surfaces come from the wheel swing angle combined with CNC travel along X and Y. The geometry has nothing in common with the spherical case, which is why CG-140 is its own machine rather than an option on another one.
- Bores are cut by a 30,000 rpm electric spindle working the inside wall of a ring or window — a separate operation that BG-50 runs unattended once the fixture is clamped.
This equipment is built for precision optics manufacturing. It is not for architectural glass, not for mirror shops, and not for ophthalmic Rx laboratories — if that is the work, we are the wrong supplier and would rather say so before you send a drawing.
Where an optical lens grinding machine sits in the line
Generating is one station of six. What you choose here changes what the next two stations have to do.
- Before: blanks are sawn from ingot or block on a closed-loop diamond wire saw. Kerf and edge chipping at that stage set the allowance this step has to remove.
- After: the generated surface goes to fine grinding and polishing, where the swing geometry — upper swing for concave, lower swing for convex — decides the figure.
- Then: outside diameter and optical axis are settled at edging and centering, the last mechanical step before coating.
- All of it together: the complete lens fabrication line, including loading, stacking and in-line inspection, laid out as one proposal with cycle times.
An optical lens grinding machine bought on diameter alone tends to surface as a bottleneck two stations later. If the line is being planned rather than patched, tell us the part and the annual volume and we will lay out all six steps — the machines in this step are also listed by process on the equipment overview.
What do buyers ask before they choose?
Can one machine cover Ø4 to Ø120 mm?
No. Chucking, spindle power and stroke all scale with the part. Shops running that whole span normally pair a small bowl-fed automatic with one larger manual or CNC generator rather than compromise on a single frame.
How much allowance should be left for polishing?
It depends on the material and the figure specification, so it is agreed from your drawing. The generated surface has to be good enough that the polishing cell corrects figure rather than removes damage.
Is a manual generator a false economy?
Not if the mix is wide and the runs are short. A manual optical lens grinding machine carries the same spindle accuracy class; what you give up is unattended running, not surface quality.
What has to be quoted besides the machine?
Diamond wheels and fixtures for your part range, destination voltage and CE configuration, freight, installation and training, and a first spare-parts set. These belong in the budget from the start.
How long does a changeover take?
On the automatic models it is a fixture and a program recall rather than a rebuild. The realistic figure for your specific parts comes out of the trial run, which is why we ask for two or three representative blanks.
Can the machine be integrated with loading equipment?
Yes — basket loading and stacking units feed the generating and polishing stations directly. They are specified with the line rather than bolted on afterwards, so the tray and basket formats match at every station.
Send the part — get a machine recommendation
You do not have to arrive at a model number on your own. Send a drawing, the material and the annual quantity, and you get back a specific optical lens grinding machine, a cycle time estimate and the trial parts to check it against.
- 1 · You send — drawing or sample, material, batch size and target cycle.
- 2 · We answer — model, wheel specification, feed stages and an estimated cycle time.
- 3 · We prove it — free trial run on your own blanks, parts returned with the process sheet.
- 4 · You decide — firm quotation including tooling, freight, installation and training.