Despite the mirror name, this is a whole-set upgrade: an aluminium laser head with air-assist nozzle plus mirror mounts, set up in this option for a 20mm lens at 50.8mm and 20mm mirrors. It replaces the stock K40 head and mount hardware in one go.
Read the name carefully. This is not a pack of mirrors. It is a laser head with an air-assist nozzle, sold with the mirror mounts that carry the beam to it. In the Whole Set (20-50.8) option, the head takes a 20mm lens at 50.8mm focal length and the mounts take 20mm mirrors.
Why replace the whole set at once? The stock K40 head takes a small 12mm lens and has no air nozzle. The stock mounts are often stamped or loosely machined, which makes alignment drift. Doing head and mounts together gives you matched parts and a single alignment job instead of three.
ZQDWMND sells the same design with 12mm and 18mm lens seats. The 20mm option catches more of the beam, which gives alignment margin, and 20mm lenses come in the widest choice of focal lengths and grades.
The description does not spell out whether a lens and mirrors ship in the set. Confirm it with ZQDWMND, and budget for a 20mm lens and three 20mm mirrors if they are not included. A new head with old, burned optics wastes the upgrade.
The head is the same family ZQDWMND sells on its own as the ZQDWMND K40 laser head, which is the route to take if your mounts are already good.
| Spec | Value |
|---|---|
| Set type | Laser head with mirror mounts (whole set) |
| Option | Whole Set (20-50.8) |
| Lens diameter (this option) | 20mm |
| Lens diameters offered | 12, 18 or 20mm |
| Lens focal length | 50.8mm |
| Mirror diameter | 20mm |
| Material | Aluminium alloy |
| Finish | Black oxidation, rust and corrosion resistant |
| Air assist | Nozzle built into the head |
| Mounting hardware | Joint plate and belt fastener |
| Lens retention | Locking ring with plastic buffer ring |
| Machine fit | 2030, 4060 and K40 laser engravers |
This design is built for the family of small Chinese CO2 machines, the 2030 and 4060 as well as the K40. K40s differ between factories, though, and brackets that line up on one machine may need new holes on another. Treat installation as a workshop job, not a five-minute swap.
If holes do not line up, drill new ones in the plate rather than forcing the carriage. A head that sits crooked on its carriage throws the beam off across the bed.
New mounts rarely sit at the old heights, so expect to pack the tube up or down until the beam meets mirror one dead level. Level and square each mount with the tape-target routine in the K40 alignment guide.
Set aside a full afternoon. Most of it goes to alignment, not to the spanners. Keep the stock head and mounts in a labelled box; if the new parts fight you, you can put the machine back into service the same evening.
The biggest practical gain from this set is the nozzle. Air blown down through the head pushes smoke and flame away from the cut, which means cleaner edges, less charring on wood and a lens that stays clean far longer. It also cuts the fire risk that comes with a K40 cutting plywood without airflow.
The nozzle is only half of it. You need an air source and a hose to it:
The buffered lens ring earns its place. ZnSe is brittle, and a bare metal ring tightened hard can chip or crack the edge of a lens. The plastic buffer spreads the pressure. Snug the ring by hand and stop.
Fit the lens curved face up, toward the beam coming down from mirror three. Handle it with gloves at the edge only. A chipped or burned ZnSe lens is hazardous, since its dust and fumes are toxic; bag it whole rather than trying to rescue it, and take it to hazardous-waste collection.
Route the air hose along the gantry with enough slack for full travel. A hose that snags at one corner can drag the head out of square mid-job. The upgrade guide ranks air assist near the top of K40 upgrades for exactly these reasons.
The choice is between replacing everything at once and upgrading the head alone. A whole set suits a K40 with tired stock mounts. A head alone suits a machine whose mounts already hold alignment.
| Option | Covers | Lens seat | Best when |
|---|---|---|---|
| ZQDWMND whole set (this) | Head and mirror mounts | 20mm, FL 50.8 | Stock mounts are poor |
| Cloudray K Series whole set | Head, mounts, lens and Mo mirrors | 20mm, FL 50.8 | You want optics in the box |
| Cloudray K40 head | Head only | 12 or 18mm, FL 50.8 | Mounts are fine |
| Lightobject K40 head | Head only | 12, 15, 18 or 20mm | Mounts are fine, flexible lens choice |
The Cloudray head cannot take a 20mm lens, which matters if you already own 20mm optics. The Lightobject head accepts all the common sizes and is the upgrade many owners fit first.
Go over these points:
Just bought the machine? Learn its quirks on stock parts with the K40 how-to first. Then upgrade with a clear idea of what you are fixing.
No. It is a laser head with air-assist nozzle and mirror mounts. In this option the head takes a 20mm lens at 50.8mm focal length and the mounts take 20mm mirrors.
It is designed for 2030, 4060 and K40 machines, but K40 carriages vary between factories. Expect to check hole positions and possibly drill the joint plate.
The description does not state it clearly. Confirm with ZQDWMND before ordering, and budget for a 20mm lens and three 20mm mirrors if needed.
An air pump or a regulated compressor with a water trap. Aquarium pumps suit engraving; cutting benefits from a stronger dedicated pump.
Yes, from scratch. New mounts and a new head change the beam path, and the tube itself may need packing to meet mirror one square.