A blue-anodized air-assist head sold four ways, from bare head to head-plus-lens-plus-mirror, with a separate mirror-mount set for gantries that need more than a head swap.
The FONLAND head is a blue-anodized aluminium air-assist head that bolts where the stock K40 head sits. It holds a 20mm mirror, the same size your K40 already runs, and takes D12 FL50.8, D16 FL25.4 or D18 FL50.8 focus lenses. What sets it apart is how it is packaged: four sets built on the same head, so you can refresh the whole last stage of the beam path in one order.
An O-ring comes with the head so it can seat 12mm, 15mm or 18mm lenses. It does not take a 20mm lens; for that you need the Lightobject head or FONLAND's own mirror-mount sets.
The mirror in Sets B, C and D is gold-plated silicon. Silicon mirrors reflect well and shed heat, but the coating scratches if you scrub it. Clean with a soft swab and lens fluid, drag once, and never polish in circles like a windscreen.
| Spec | Value |
|---|---|
| Maker | FONLAND |
| Model | K40-Laser Head |
| Body material | Aluminium alloy |
| Finish | Blue oxide coating |
| Air assist | Built-in air-assist connector |
| Air plug outer diameter | 5.0mm |
| Hose | 5 x 8mm silicone suggested |
| Focus lens fit | D12 FL50.8 / D16 FL25.4 / D18 FL50.8 |
| Lens adapter | O-ring included for 12, 15 or 18mm lenses |
| Mirror diameter | 20mm |
| Sets B, C, D add | USA ZnSe focus lens + 20mm Si mirror |
| Mount-set contents | Head + 1st and 2nd mirror mounts, no optics |
| Mount-set 12mm lens tube | 56–74mm height adjustable |
| Mount-set 18/20mm lens tube | 78–82mm height adjustable |
| Mount-set weight | 0.6 kg |
| Head package | 3.94 x 3.94 x 2.36 inches, 2.11 oz |
Set C is the odd one out, and it earns its place. A 25.4mm focal length is half the K40's standard 50.8mm. A shorter focal length focuses the beam to a smaller spot, which sharpens fine raster detail, but the depth of field shrinks with it.
| Lens | Best at | Trade-off |
|---|---|---|
| D12 FL50.8 | General K40 work, like the stock lens | Small lens, fewer replacement choices |
| D16 FL25.4 | Rubber stamps, fine text, photo raster | Very shallow focus; poor on thick cuts |
| D18 FL50.8 | Everyday cutting and engraving | None worth noting on a K40 |
A short lens punishes a warped sheet. If the material bows a millimetre or two, the spot goes out of focus across the job. Flatten the stock, pin it down, and check focus at several points on the bed.
Every lens swap means a new focus height. The K40 setup guide covers the ramp test that finds it in a few minutes.
Stamp makers are the natural buyers for Set C. Rubber stamps want crisp shoulders on small lettering, and a smaller spot delivers that. For signs, coasters and general cutting work, Set D's 18mm lens is the easier daily driver and the simpler one to replace.
Do not expect the short lens to cut faster. It concentrates energy in a smaller spot at one height, but the beam spreads quickly above and below that point. On 3mm plywood the cut walls come out tapered, and on thicker stock the bottom of the kerf may never clear.
The air-assist head is a swap: unplug the machine, pull the stock lens, unbolt the stock head, fit the FONLAND head, then seat the lens curved side up. The air plug is 5.0mm across, and FONLAND suggests 5 x 8mm silicone hose. Route it along the gantry with slack for full travel.
FONLAND also sells head sets with matching 1st and 2nd mirror mounts, in 12mm, 18mm and 20mm lens-tube versions. These suit a bent or worn beam path, or a rebuild where you want every mount from one maker. They come without mirrors or lenses.
The adjustable lens tube is the mount set's quiet advantage. Raising or lowering the tube moves the focal point without touching the bed, which helps on K40s with a fixed clamp plate. Follow the alignment walk-through once the mounts are in.
Before the first cut, fire a low-power pulse onto masking tape over the nozzle. The burn mark should sit in the middle of the opening. If it clips the edge, the beam is hitting the cone wall, and you will lose power and heat the head.
Three K40 air-assist heads share almost the same outline, so judge them by the lens seats they take and the parts packed with them. The FONLAND and Cloudray heads both list D12 FL50.8, D16 FL25.4 and D18 FL50.8 lenses with a 20mm mirror. The Lightobject head goes up to a 20mm lens but ships bare.
None of these heads raises tube power. They put more of what the tube makes onto the work by keeping smoke off the lens and flame out of the cut. If a machine cut well once and now struggles, clean and align before buying parts; the upgrade order puts those jobs first.
Check these before you pay:
If you run the machine for a small business, buy two lenses with the head: one to fit and one sealed in a drawer. A cracked lens halfway through an order stops the machine dead, and a spare costs far less than a lost weekend.
No. It takes D12, D16 and D18 lenses, and its O-ring covers 12, 15 and 18mm. FONLAND's mirror-mount sets come in a 20mm lens-tube version.
Sets B, C and D each add a USA ZnSe focus lens and a 20mm Si mirror. Set A is the head alone.
Fine engraving and stamp making. Its short focal length gives a smaller spot but a very shallow focus, so keep it off thick cutting jobs.
No. They include the head and the 1st and 2nd mirror mounts only; move your mirrors across or buy new 20mm ones.
