Fiber Laser Training

Each user should only run one laser at a time and not leave the room during operation. We ask that members not use both lasers at the same time as a courtesy to other members.

Use the Laser Signup Sheet to reserve time on the laser.

Capabilities:

60W JPT MOPA EM7 with enclosure
Cuts thin steel, brass, aluminum, and other metals up to 2mm, but it takes a long time.
Etches or marks aluminum, the anodized coating on aluminum, brass, stainless steel, slate, glass and ceramics.
Marks stainless steel with black or other colors (It is hard to predict the colors.)
Working size: 110x110mm (F160) and 210x210mm (F290) lens
Software: Lightburn (For Fiber it works a little differently.)
Connection: The fiber laser only connects through USB, not the network, so you can't easily use your own computer.

SAFETY WARNINGS

This laser can be dangerous if used improperly: It can cause serious deep burns if the safety interlock is bypassed. It can start a fire if flammable materials are in the beam. It can produce toxic fumes with some materials.

Use of this laser is the responsibility of the member, and the member should take note of whether the material being marked is suitable. First, do not mark or cut wood, paper, polystyrene, or any other ﬂammable materials. The Thunder Laser is suitable for some of these, but the fiber laser does not have air assist blowing on the laser beam, so fire is much more likely.

Items that have been etched with the laser may be VERY HOT. Touch your work piece with caution!

Please keep all doors on the laser surround shut properly while the machine is in use, and ensure that all items to be lasered can ﬁt within the enclosure.

Exercise special caution when working with conductive materials, as the buildup of their dust and ablated particles may damage electrical components, cause short circuits, or produce other eﬀects, including reﬂected laser radiation.

Some items have coatings on them that produce dangerous fumes. One example is galvanized steel: this is most of the steel you ﬁnd at hardware stores, especially for construction or outdoor purposes. While the ﬁber laser is capable of marking these items, the coating on them contains zinc and lead and can cause serious health issues to the people in the area.

Do not place anything in the path of the laser that should not be marked. The laser is not necessarily safe just because it is currently not cutting. Use common sense and precautions, and treat the laser as if it could spontaneously turn on at any moment.

Do not place reﬂective items in the path of the laser. The reflected beam can cause damage to the wires and structure of the laser and enclosure. To prevent reflections, a layer of tape can be applied.

Do not place ﬂammable items in the path of the laser.

More items known to be dangerous to laser etch:

Leather containing Hexavalent Chromium (Cr[VI]). (Vegetable tanned leather is safe but stinky.)
ABS produces cyanide gas when heated
Plastics containing Bromine, like some fire retardant plastics
Plastics containing Chlorine including Polyvinyl Chloride (PVC, Vinyl, Sintra, etc.) Some fake leather is actually PVC.
Plastics containing Fluorine, including Polytetraﬂuoroethylenes (Teﬂon, PTFE, HDPE etc.) There are plenty of halogen-containing-polymers, so if your item is plastic and you aren't sure it's on the safe plastics list, just avoid it as it can be lethal.
Phenolic Resins, including various forms of Epoxy
Galvanized metals, and metals containing zinc, lead, or other toxins.
Pot-metal is a generic term and may contain any number of hazardous metals.

(One reference: Accurl)

OPERATION

POWER ON

Read the safety warnings above. I know you skipped that part.
Power on the mini PC beside the ﬁber laser (password hackrv@@) and open LightBurn.
Turn on the yellow power strip on the wall to the right of the laser. Listen to be sure that this turns on the ventilation. (It turns on all three fans, to keep exhaust from going over to the other laser.)
The laser is the silver box on the floor to the right of the table. Turn the red emergency stop button clockwise and pull out. This will turn on the laser.

FOCUS

Place you material under the left side of the head. The focus lines for both lenses are on a sticker on the side of the laser head.

The focal sticks are hung on the wall behind the laser computer. Open the enclosure door on the side closest to the computer and make sure your focal stick (410mm long for the F160 lens) lines up from the red line marked on the sticker on the laser head to the top of your material to be

marked.

Burn!

Place your material in place underneath the laser head. Open LightBurn and open your prepared ﬁle or start a new project.

Select the layer of your graphics.

Search in the Materials Library for presets that best match the project. To do this, ﬁnd the tab labeled Material Library at the bottom of the window in LightBurn. Select your material, then the subcategory. For example, Steel, black.

Click Assign. This copies these settings from the library to the chosen layer. If you have one file for cut and engrave, repeat the process with different layers for each.

Press CTRL-A to select all. Press the P key to center your image in the laser work area.

Select the Laser pallet (next to the Material Library tab), and click Frame. The laser will project a red image on the bed. (This is not the work laser and is safe.) There are options in the Frame dialog: It can be a simple outline, the outside shape of your image, or a detailed sketch, with or without inside shapes. You can use the more detailed types to confirm orientation. (Up on Lightburn is towards the gantry on the laser.) For alignment, switch back to Hull. It is much faster.

Move you material to line up with the red framing laser image.

Shut the enclosure door. (The safety switch is at the top left of the enclosure in the front. If LightBurn gives you a door safety switch error, the laser will not start.)

Confirm everything is the way you want it.

Click Start. The laser will immediately start and will mark your material or anything else in its path.

ERRORS and Problems

You must always keep an eye on the laser in operation. With the fiber laser, cutting metals can take a long time, so it is permissible to leave the area briefly but only if there is nothing flammable inside the laser enclosure.

In case of fire, open the door and the safety interlock should turn off the laser. If it does not, press the big red safety stop used to turn on the laser. Remove the burning material if possible, or get the spray bottle of water marked FIRE! usually found on the Thunder Laser and spray it.

SHUT DOWN

When you are done, turn oﬀ the laser by pushing in the Emergency Stop button on the laser. (far right, red button).
If no one is using the CO2 laser, turn oﬀ the yellow power strip. If someone is using or is about to use the CO2 laser, leave the yellow power strip on.
If you are done with the computer, please sign out, because the automatic sleep settings can interfere with laser operation so they have been disabled.
If you used a lens other than the 290, please put the 290 back on.

HOUSEKEEPING

If your work on the laser produced any dust (such as in the case of reliefs or heavy etching on slate material), please vacuum it out of the enclosure with a shop vac and carefully use compressed air to remove dust from the lens.

Be sure that no work piece or jigs are left inside the laser enclosure.

Check and be sure that the tools for the laser are in reasonable and visible places on the bench (metric ruler, infrared thermometer, etc.)

Check the trash in the area. If it is full, please take the trash out.

Advanced Laser Control Settings

SPEED

Speed controls how much time the laser spends on a given line, so the slower the speed the more energy and heat is put into any given square mm of space. So in many cases a lower speed could be more

aggressive, but this may change based on material properties. This may go up to 7,000 mm/s. The setting goes as low as 1mm/s, but this isn't a practical speed (50mm/s is reasonable).

POWER

Power is the percentage of total power used, so in the case of this equipment, 100% power = 60w maximum power. The higher the number, the more energy will go into the material. The range is 0 to 100.

FREQUENCY

Kind of like sandpaper: the lower the frequency, the more aggressive. The higher the frequency, the more smooth and polished the results will be. The frequency range for the JPT MOPA is 1khz-600khz where 1

would be the most aggressive. To transition from removing material to cleaning up, you should make several passes, increasing the frequency each time.

Q-PULSE WIDTH

This is the time between the start of one pulse and the start of the next pulse. For basic black marking, 200ns works ﬁne. Change these values to get different color outcomes for the same power/speed settings.

If you choose a setting outside the range, the machine will not let you start a job. The eﬀects of this setting are subject to many variables including material, ambient temperature and humidity, material temperature and thickness, etc. Try to do a test burn if you change this setting to dial in your results.

MANUALLY FIND THE FOCAL LENGTH

This should not need to be done, as the focus stick should be the right height. However, if you are experiencing problems, this is an easy thing to do to ensure you are getting the best results from the laser.

1. Launch LightBurn software and start a new project. Make a small square near the center. You can center work by selecting the pointer tool, selecting your shape, and typing P on the keyboard.

2. In the Cuts/Layers window, double click your work layer and use these settings:

Speed: 1000mm/s
Frequency: 25khz
Max power: 80
Line interval: 0.025
Q pulse width: 200ns
Global passes: 1
Bidirectional ﬁll: ON
Cross hatch: ON
Auto-rotate: OFF
Flood ﬁll: OFF
Wobble: OFF
Fill all shapes at once: ON
Enable dot width adjust: OFF
Ramp outer edge: OFF

3. Click OK.

4. In the Laser>Frame menu, check Run Continuously.

5. Check that your material is under the laser (the red dot should be framing the area it will mark) and then click Start.

6. The laser will start to mark the material. Using the up and down buttons, adjust the height of the laser head until the light from the laser is at its brightest and the noise from the laser is loudest.

7. Once you have found the brightest and loudest position, click Stop.

8. Wait for the work to cool sufficiently and then measure the height from the work to the red line on the laser head sticker. This is your optimized focal length. You can make a touch stick that length so that you can quickly set the height of the laser head housing to this position over your work each

time.

CUTTING

While the laser is capable of cutting, it takes significantly longer than marking, and may cause damage to materials due to excessive heat. You should check the material being used. At the time of this writing, cutting material thicker than 2mm requires stopping after the laser has cut 2mm and lowering the Z axis by

2mm to continue cutting in focus. We do think it's a simple software ﬁx but we don't know if or when the software will be updated.

At the time of this writing, we have only cut steel and brass, for which the following settings were used.

To cut lines/outlined shapes:

Power 100%
Frequency 20khz
Q pulse width 200ns
Speed 50mm/s
Wobble ON

Steel took 100 passes per mm, and brass took 30 passes per mm. Be prepared for trial and error. When cutting, place the item to be cut on a riser made of durable material. The riser will get VERY hot and may be etched somewhat.

There are 12”x12” ﬂoor tiles available to put under your work piece in order to protect the bed. If you remove a significant amount of material from the protective tile, please bring in a replacement. Big box hardware stores oﬀer inexpensive individual tiles for sale.