Laser Cutter #2
TRAINING REQUIRED BEFORE USE.
(Note: Access control is ad-hoc, Ask someone to add you after you have received a walkthrough.)
Model JD90125
Bed: 1250x900mm
Laser: 100-150W (130W rated, 150W peak) glass CO2
Accessories: CW-3000 chiller, rotary axis
Safety
There is always a fire risk when using the laser. The laser should not be left unattended during a cut.
Failure to pay attention to the laser can result in this:
Recommended Settings
Please add your own preferred settings here, but do not edit the existing entries. If you believe a setting is inappropriate, use strikeout and add a new entry with your corrections. Add your name to the notes so that other users can make an informed decision where there is a conflict of recommendations.
The test were done in the centre of the cutting bed.
Material | Cut Speed | Cut Power | Notes |
Acrylic 1mm | 30 | 40 | Miron |
Acrylic 2mm | 28 | 100 | Miron |
Acrylic 3mm | 17 | 100 | David |
Acrylic 4mm | 15 | 100 | Miron |
Acrylic 5mm | 12 | 100 | Miron |
Acrylic 8mm | 4 | 100 | David |
Acrylic 10mm | 3 | 100 | Miron |
Ply 3mm | 30 | 100 | Miron - cuts simple things fine at speed 50, but stutters when cutting curves. 30 is safer |
Ply 4mm | 20 | 100 | Miron |
Ply 6mm | 9 | 100 | Miron |
MDF 2mm | 30 | 100 | Miron |
MDF 3mm | 22 | 100 | Miron |
MDF 4mm | 16 | 100 | Miron |
MDF 6mm | 10 | 100 | Miron |
Paper | | | |
Card | | | |
Engraving Laminate 1.5mm | 50 | 100 | Miron |
Engraving Laminate 3mm | | | |
Material | Engrave Speed | Engrave Power | Notes |
Acrylic | 350 | 50 | Miron |
Ply | 500 | 30 | Bart |
MDF | 350 | 50 | Miron |
Laminate | 350 | 50 | Miron |
Minimum power setting for the laser to turn on: 19
To Do
Before general use:
Create and fit a bracket to hold the air assist tube away from the drive belt
Clean laser tube water channels
Test optical power output and calibrate to a sensible maximum (e.g. 66% of peak rating)
Create chart of power/speed settings for common materials (as a basic rule, multiply speeds from the old chart by 3x)
Documentation for existing laser cutter users
Update docs:
Fix extraction
Fume extraction is unacceptable at the moment. Fumes or light haze will fill the room. This appears to be caused by fumes re-entering via the window, and not by lack of extraction in the cutter itself.
Possible solution: seal the window properly. Better seals have been installed and the situation is better, but not good enough.
Possible solution: divert the fumes up or down away from the window.
Soon, but don't wait:
Fit replacement alignment laser (ordered 6th April)
Fit extraction duct mountings on right-hand access door (order delayed, re-sent 10th April)
Create spare focus jigs (requires 12mm acrylic, or a new design)
Build and install monitoring system (laser usage, temperature logging)
Fully check and adjust alignment
Re-level bed.
Later:
Order spares: silicone tubing, mirrors, lens, rotary attachment o-rings
Purchase and install tinted polycarbonate window, 1185x920mm.
Install vent in G2 door to provide better air flow.
Upgrade internal (to chassis) extraction ducts (use PU ducts instead of foil, merge rear and hopper 100mm ducts into a 150mm duct for egress). Optionally replace flexible door-join with a foam seal. ACTION: MIKE
Upgrade cutter-to-blower duct to PU or semi-flexible aluminium 150mm. ACTION: MIKE
Install ducts to roof and upgrade blower, to avoid releasing fumes onto courtyard users. ACTION: PETE
Install LED lighting. ACTION: ALFIE
Replace broken acrylic cover on front-loading slot.
Guide for existing laser cutter users
What’s changed?
The bed is larger, up to 1250x900mm.
The Z axis is deeper, so large items can be engraved.
The laser is more powerful (estimated at 100W or more) so cutting is faster or thicker materials may be used.
A rotary axis accessory can engrave cylindrical items.
What do I need to know about using it?
We now have access control. All members will have access to start with (we might make a formal training record later). Non-members will need a member to enable the laser cutter before use.
Focusing the laser (for different materials) is slightly different. The nozzle can be adjusted without moving the Z axis. Users must still know how to adjust the Z axis in case it's been left too high or too low.
The enclosure is very large and smoke/fumes take longer to clear. Leave the case closed for 10 seconds after cutting to allow the extraction system to catch up.
The air assist is adjustable. Always make sure that it's enabled (on the top control panel) and that the valve (on the right hand side) is open. It's okay to reduce the air assist for delicate materials like paper, but there should always be some air flow enabled to protect the lens.
The window is clear. This should absorb the infra-red laser, but it doesn't block much of the visible flash when the laser hits the honeycomb bed. So don't stare directly at the cutting point.
The window is tinted as all hell. This should absorb the infra-red laser and most of the light from the laser. Emphasis on the should.
Checklists
Powering-Up
check that the bed is clear of obstructions
check that the Z-axis is below the level of the cutting head (we don’t want the head to crash when it attempts to home itself)
make sure that all the access panels are closed
switch-on the laser cutter at the wall
log-in with your access token
press the green start button
check that the air assist is switched on and that the valve on the right-hand side is fully open
If it won't start:
check that the door on the right-hand side is properly closed
check the emergency stop button (twist clockwise to reset)
check that the access control is logged-in (should say Idle or Active)
Switch off the cutter and report a fault:
Before Cutting
position the material on the bed and move the nozzle over the material
release the locking ring on the nozzle (turn
locking ring clockwise)
place the 12mm focus jig between the nozzle and the material, and lower the nozzle down to touch it
re-secure the nozzle and remove the jig (turn
locking ring anti-clockwise)
check that the air assist is switched on and that the valve on the right-hand side is fully open
After Use
press the datum button to return the laser nozzle to it's home position
leave the system running for a few minutes to allow the fumes to be extracted and the tube to be cooled-down
remove any scraps from the cutting bed (use the vacuum cleaner if the pieces are small enough to get stuck in the honeycomb)
press the red stop button
press the logout button on the access controller
Troubleshooting
System won't start up
check the emergency stop (twist clockwise to reset)
check that the right-hand access panel (electrical controls) is closed properly
check that the rear access panel (laser power supply) is closed properly
check that the access controller is logged-in
Nozzle quickly "jumps" and looses alignment while moving between cuts
In LaserCut 5.3, File>Machine Options>Worktable
Make sure “Quick speed” is set to a sensible value like 300, work-acc to 500 and space-acc to 500
Nozzle moves but doesn't cut
check that the lid is closed (the microswitch should make a click as it closes)
check that the chiller is powered-up, showing a green Normal status and that it is connected to the laser cutter
check that the correct power level has been selected
Chiller alarm sounds
At startup: if the alarm sounds for more than a couple of seconds, TURN IT OFF and report a fault. There may be insufficient water, there may be a blockage or a pump failure.
During use: if the alarm sounds during normal use:
pause the cutting session
check the temperature on the chiller's front panel (it should be in the range 10-23℃, roughly room temperature)
if the temperature is too high, try waiting for the chiller to bring the temperature down
if the temperature doesn't fall then there is probably a fault
even if the temperature does fall, REPORT A FAULT as the chiller should normally be able to keep up
Log
2018-03-25:
2018-03-30:
2018-04-11:
2018-05-04:
2018-05-14:
Internal ducting upgraded (PU ducts, internal combiner to 150mm and 150mm to the blower). Significant improvement to extraction, but more testing is still required to see whether fumes are re-entering via window.
2018-05-15:
Mike found a leak in the flexible square section after the blower. It has been plugged with hot glue and seems to be fixed. The smell of fumes in the corner while cutting is reduced now, but still there. There may be a small leak where the square tube seals against the wood panel (on the left behind the blower).
2018-05-28:
2018-07-14:
2018-07-19:
2018-09-22:
2020-03-03:
2020-08-08:
The mirrors were realigned, the actual laser tube was sitting about 2mm too low and the field was slightly crooked with the top right corner shooting too high. It seems to that the body of the laser had bent back to its original geometry from the time we've got the laser in 2018. It has probably happened due to the different location and maybe better floor. The intermittent issue of the tube switching off could not be replicated, the HV wires were checked but no obvious burn or oxidation marks have been identified.
Other Specifications (for maintenance)
Water tubing: silicone, 12mm OD, 8mm ID, 2mm wall
Chiller: CW-5200
Air assist compressor: Hailea ACO-328
Air assist tubing: silicone, 12mm OD, 8mm ID, 2mm wall
Mirrors: 3x 25mm diameter
Lens: ZnSe, 20mm diameter, 50.8mm focus
Laser PSU: Reci DY20
Laser tube: ZN-1650 (130W rated power, 150W max, 30mA)
Resources
Access Control
The access control unit will be external to the laser cutter chassis and connected by a cable:
GND
5V supply (from laser cutter, always on)
Enable power-up (open drain)
Current clamp A
Current clamp B
(additional pins may be required for better active/idle detection)
Monitoring
An external unit will contain an ESP8266 and LCD. It will connect to the main chassis by cable:
GND
5V supply (from laser cutter, always on or switched)
One wire bus for DS18B20 temperature sensors
I2C SDA
I2C SCL
Laser enable pin
Laser power level pin
Laser powered-up signal?
Laser cutter in use signal?
The monitoring device will:
Log laser tube time
Log temperatures (ambient, coolant out/return, bed, exhaust)
Detect cutting sessions and report the most recent on the LCD
Potentially, log fume/particulate levels