Redsail laser — Maintenance and troubleshooting
Maintenance and troubleshooting for the Redsail laser. Dated work is in the maintenance and repairs log.
Laser out of order? Put a note on it and post in Slack #laserskärare.
Troubleshooting
Problem | Check |
|---|---|
Cuts poorly or not at all | Almost always the lens or mirrors. 1) Reasonable power/speed? Compare with the logbook. 2) Focus correct? Use the focus block. 3) Head warm after a few minutes' running? The mirrors may need aligning — post in Slack. 4) Lens clean, the right way up and in the right position (see below)? |
Cuts differently across the table | Some variation is normal. Large variation: check the table is level and the mirror alignment. |
Wrong dimensions in Y (front–back) | Rotary switch still on (machine or LightBurn)? See Rotary module. File scale correct? |
Machine fills with smoke | Filter probably needs changing (see below). |
Laser on but won't fire | Light doesn't go green on the black button? Check the lids are fully closed. (Beacon is yellow normally, green when firing.) |
Nothing happens on green button | No power to the machine: emergency stop pressed? Power cable seated? Breaker or RCD tripped? (Right-hand of the two panels in the cabinet just outside the Wood room.) |
LightBurn: "laser might be busy" | Laser on and idle? Right-click Devices in LightBurn to reconnect. Memory full? Delete some files under Files on the laser. |
Planned
Replace all three windows with thicker acrylic (≥ 5 mm), possibly hard-coated for scratch resistance.
Laser head
The lens in the head focuses the beam to a point; cutting happens near the focal point.
Laser head
Lens detail
Cleaning or replacing the lens
The head holds one lens and two gaskets. Clean the lens with isopropanol now and then; permanent spots mean replacement. Replace the gaskets when they're burnt or dry (they should be milky white). Isopropanol, lens tissue, spare lenses and gaskets are in the maintenance cabinet.
Removing the head:
Remove a few slats under the head for space.
Disconnect the air hose: push in the blue ring and pull the hose out. (To refit, just push it in.)
Loosen the focus screw and remove the head.
Lens tool | Head removed | Air nozzle removed |
|---|---|---|
Lens tool | Head removed | Air nozzle removed |
Removing the lens:
Unscrew the lower air-assist part.
Looking up into the tube you'll see the lens and a retaining ring with two holes.
Unscrew the ring with the two-pin tool.
Careful — the lens breaks if dropped.
Part order | Tube from below | Tube from above |
|---|---|---|
Parts in the tube | Tube from below (threaded end is the air-assist end) | Tube from above |
All head parts with the tool
Reassembly:
Fit the parts in the order shown.
Lens orientation: it should magnify when you look down from the top and shrink when you look up from below.
Lens position: in the longer section of the tube, position 3 (our lens has 63.5 mm focal length).
Screw in the retaining ring, refit the air-assist part.
Refit the head, tighten the large ring, reconnect the air hose.
Assembled head
Power meter
A laser power meter is available for checking the tube's output.
Instructions
Power meter
Changing the filter
About every 3 months, or when the machine fills with smoke. Filter: 20 mm G4 filter mat (white fluffy roll, behind the laser next to the duct).
First check:
Yellow damper behind the machine is OPEN.
The fan just below the damper is running.
Air assist starts when you start a cut.
The laser can be used (it checks sensors you can't).
Ventilation
Filter roll
Steps:
Protective clothing and plastic gloves (it's very dirty).
Open the red cabinet behind the laser (opens on the right).
Pull out the filter frame.
Unclip the old filter (the four edges on the side without the mesh fold out 90°).
Put the old filter in a bin bag.
Cut a new piece from the roll to fit the frame and clip it in.
Refit the frame with the filter towards the laser and the mesh towards the duct — otherwise the airflow pulls the filter off the frame.
Close the cabinet. Write the date in the maintenance log and on the post-it note.
Test the laser. If still smoky, report a ventilation fault.
Dirty work — protective clothing
Background
When the laser was shut down for ventilation problems, a PLC was added to read sensors, only allow firing when it's safe (ventilation working etc.) and show status on the light beacon. See Control system.