Laser Cutter - Bumblebee

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This is one of the two nearly identical laser cutters in the space. They have 3'x4' beds and 150 watt tubes. This one is named Bumblebee becasue it is yellow and black, as compared to Wolverine, which is yellow and navy blue.




Bumblebee

Basic Info

  • Ownership: Group-owned, purchased with funds collected from far and wide.
  • Location: West wall, you can't miss it.
  • What it looks like:
alt text

Manufacturer Information

  • Make/Model: Jinan G. Weike / WKLaser LC1280
  • Part Number: not specified

Documentation

The setup manual, File:OPERATIONAL MANUAL OF MACHINE xin USB.pdf is worth reading, if only for a laugh. Inside the cutter, a Leetro MPC6515 control board coordinates the motors and laser firing. Its documentation is freely downloadable. So much grief has arisen from the awful state of the documentation and software, that an entire Chinese laser support forum has arisen for the hapless owners of these machines help each other.

Rules

If you are not trained yourself, operation of the laser cutter must be done under the supervision of one of the trained operators. (A list can be found on the clip board in the zone) Trained operators are: Matt A., Roger S., Nate B., Terry W., Andrew M. and Devon T. See the section below about Damage Prevention.

i3Detroit asks that users donate $0.25 per minute or $15 per hour that the beam is active. This is to replace consumables, especially the expensive bulb. There is a wooden donation box.

Approved Materials List

Instructions

General Instructions

Get material that will fit on the bed of the laser cutter, which is 3'x4' (optimal cutting area 34" x 46"): 4 feet wide from left to right, and 3 feet long from the front to the back. Your piece must be able to fit on the bed itself, because the bed will lower to put the surface of your material in focus. However, in case anyone needs to know the whole interior of the bay for some reason: there is 51 inches of clearance between the two rails the gantry runs on (the same width as the machine's bay door). 51 inches is also the measurement from the front lip to the back wall of the machine, but the door itself takes up 3/4 of an inch of that.

Time-of-cut Checklist

  1. Place material (square to edge of honeycomb).You can also run the head left / right and watch the red dot to see if it moves parallel to the edge of the material. Adjust as needed.
  2. Cover inactive honeycomb area except an "intake" in front of the material. This directs smoke away from the gantry.
  3. Turn on POWER STRIP on floor behind cutter. This should bring up the chiller and air-assist pump.
  4. Gently pinch rubber hose from laser to chiller to trigger chiller alarm, verifying that it's awake.
  5. Assure the exhaust is open on the back of the unit, right next to the chiller. Slide the door all the way open (to the left).
  6. If the other machine is not in use, cover the vents at the back of the OTHER machine to increase the exhaust flow.
  7. Make sure there is nothing obstructing the path of the laser head toward the right rear of the working surface!
  8. Turn keyswitch to on, and wait for boot and home to complete.
  9. With the D-pad, jog head over to center of material.
  10. Press "Z" to enter the mode to raise or lower the bed.
  11. Keep one hand over emergency-stop. Press "Datum" to auto-focus.
  12. Double check the auto-focus with one of the acrylic manual focus gauges. Tell the zone warden if the autofocus is off by a significant amount.
  13. Press "Z" again to exit Z mode.
  14. Wave hand under head and verify that air-assist is blowing.
  15. Download design from LaserCut software.
  16. With the D-pad, jog head to start of cut.
  17. Keep one hand over emergency-stop while using the "Test" button to check boundaries.
  18. Turn on the exhaust fan (black switchbox on wall).
  19. Lift the fire extinguisher and set it back down. This verifies that your muscle-memory knows where it is.
  20. Press "Start".
  21. DO NOT WALK AWAY. See http://www.thinkhaus.org/2011/04/03/lazzoring-is-serious-business/ for why.
  22. When cutter finishes, observe elapsed time on LCD and put money into box.
  23. Also, please remember to turn off the exhaust blower! The furnaces have to put back everything it removes.
Example of a correctly focused setup

How to use the manual focus gauge

The manual focus gauges are in the laser cutter box. They are small L-shaped pieces of acrylic with "69mm For use with 63mm lens" engraved on them, corresponding to the 63mm focal length lenses currently installed in the laser cutters. To check the focus, place the gauge on the surface of the material you are cutting. The underside of the nib should rest against the top of the knurled fitting, as shown in the pictures to the right.

To re-cut the manual focus gauge, or to modify the file for a different lens, use the files found in this thread.

Other References

Maintenance

How To Calibrate The Auto-Focus

From time to time the auto-focus gets out of alignment for various reasons gradual or sudden. The depth-finding plunger is at the wrong height. One of two things have usually happened. A: the depth-finding plunger is at the wrong height on the lens cylinder; or B: the depth-finding plunger is at the wrong height in its (gold-anodized) holder. Note: the telescoping of the assembly relative to the crossbar does NOT affect the focus, it affects the height of the honeycomb relative to the outside edge of the laser table when focused.

To adjust the autofocus, use the plastic gauge (as shown above). Adjust the position of the probe in its holder and the position of its holder on the black tube so that the top of honeycomb surface is approximately even with the surrounding edge, and there is enough of a gap between the holder and the top of the knurled ring to allow the gauge to fit between them. The set screws that secure the probe bracket to the black tube should be below the bottom edge of the crossbeam that supports the laser head.

When you are done, make sure the nozzle is tight on the end of the black tube (thumbscrew on side is also tight) and the nut that controls telescoping of the lens assembly in the black tube is also secure.

How to tell if the laser head needs cleaning

If speed for CUT in 1/8 mdf falls below 20,then check focus and have a trainer clean both mirrors and lens.

Power and Speed Rankings

TW- I have noticed that the laser seems to lose power over time. To better get a handle on this I am going to start running Cut Rankings. Every time I use the laser, I will make a test of small squares on the 1/8 mdf, which is usually around as scrap, for cutting at 100 power. They will be staggered at speeds of 5.10.15.20. I will put the results and date. If others could do this to we might start to see what we need to do.

  • Cut means fall out / Popout means req'd push to release / No Cut means not seperable
  • 6/2/13 1/8 MDF 5 CUT 10 CUT 15 POPOUT 20 NO CUT
  • 6/9/13 1/8 MDF 5 CUT 10 CUT 15 POPOUT 20 POPOUT
  • 6/10/13 1/8 MDF 5 CUT 10 CUT 15 CUT 20 POPOUT
  • 6/11/13 1/8 MDF 5 CUT 10 CUT 15 POPOUT 20 POPOUT
  • 6/12/13 1/8 MDF 5 No CUT 10 NO CUT 15 NO CUT 20 NO CUT
  • 7/31/13 1/8 mdf 30 cut 33 cut 37 popout 40 popout
  • 8/6/13 1/8 mdf 20 cut 23 cut 27 cut 30 popout
  • 8/12/13 1/8 mdf 20 cut 23 cut 27 popout 30 nocut
  • 11/14/13 1/8 mdf 12cut 20 no cut
  • 11/14/13 1/8 mdf AFTER Cleaning 20 cut 25 cut 30 popout

TRAINERS NOTE: Alcohol and cotton bundle. Convex lens side goes TOWARDS laser. capture ring tool is in white box. use tweezers for removal of oring.

Damage Prevention

The most common way the laser can injure itself is colliding its plunger with something when it moves itself. Moving itself takes place during a job, when going to the logical origin that has been set to begin or end a job, or when homing to the upper right corner of the bed. Homing takes place when pressing the Datum button, or when the machine powers on, such as recovering from an emergency stop. If the plunger is mounted on the wrong side, it can collide with the machine frame during homing. The plunger can collide with material or with weights that are holding down material. During a job, sometimes a flexible material will lift off the bed through heat curling, or when cutting releases its pent-up spring energy. Continuing the job might cause the head to collide with the newly-emerged edge.

Only use the auto-focus feature (z-datum) when plunger is over material. Otherwise, the plunger tip goes into the honeycomb without being pressed down, so the Z-motion doesn't stop itself, and crushes the lens head into the bed. Keep your hand over the emergency stop when auto-focusing. Everyone should practice hitting the emergency stop button. Pressing the emergency stop does not cause an emergency.

Be very careful when removing the emergency stop, because it homes itself during every power-on. So, be sure the lens head is free. If the table is so high that the plunger is stuck in the honeycomb, open the lower doors of the laser, manually pull the belts on the screws so that the bed goes down. After this, this procedure will have to be reversed, measuring the distance from both sides of the bed to both sides of the gantry.

Coolant failure will destroy the laser, so each time the laser is used, squeeze the coolant tube to ensure that the alarm would go off.

Be sure the exhaust is on, or the smoke gathering in the machine will damage the mechanics, the optics, and any nearby humans.

Never laser-cut polycarbonate. It is highly flammable, and will produce toxic, highly corrosive smoke. Also do not cut plastics containing chlorine. Acrylic and delrin are currently the only known-safe plastics.

Before cutting something with an reflective surface, consult a user who is qualified for training or maintenance.

If material catches on fire, hit the emergency stop, yell "fire", and use the fire extinguisher mounted to the front of the laser. Pull the pin, and spray carbon dioxide gas in a sweeping motion over the flames. It just dispenses carbon dioxide gas, not foam. This will do no damage. It's just loud.

Things that Need to be Done

New cylinders to hold different lenses,
...to make it easy and safe to change them without smudging or damage. Sector67 has indicated they may make some of these. (The existing cylinder has too narrow an opening for the lens that gives a long focal length. Its beam is so wide that it hits the lip and heats up the cylinder.)
Payment-measuring timer.
One way to do this would be to measure current to the machine and time how long it runs at laser-firing power. It would be good to put a button on the timer that would re-set it to zero.
Another way, used at other spaces, is to use the "blow" output contact from the controller, which is meant to trigger the air-assist, in case bottled gas is being used for special cutting.

Done

Payment box.
Greg Smith made it.
Laptop desk.
Standing desk built by Dustin White & Ted Hansen.
Aperture in the chassis, through which to thread the blue USB cable with a grommet.
Instead, we discovered an exit under the machine and threaded it through that. Matt Arnold used sugru on the side of the standing desk for a place to attach the end of the cable when unused.

FAQs

A list of commonly asked questions

If I have a jpeg file, how do I etch it on a piece of acryllic?
The easiest way is to import the jpeg file into the LaserCut software, then put it on an engrave layer.
If I set speed on LaserCut, what does the SPEED % mean on the display of the Laser Cutter?
The speed on the Laser cutter screen is irrelevant. When uploading files manually (Without the LaserCut software) this is where you change your speed/power. However, LaserCut handles all of this for you, and the cutter will follow your settings from the program, regardless of what they are set for on the cutter itself.
I have a jpeg of a line drawing. How can I cut a piece of acryllic using that line drawing?
It is recommended that you upload the image into a vector art program (ie: Illustrator, Inkscape) and trace the into tool paths. If you try to cut the jpeg directly, the cutter will also try to cut the artifacts in the image and not only extend your cut time, but also create the potential of ruining your image.
Do I need training to use the Laser Cutter? If so, how do I get it?
Yes, use of the laser cutters must requires you to be a member and either training, or the supervision of a trained operator. If you would like to be trained, or need assistance, you may either contact the zone wardens, or one of the trained operators listed (both on the wiki and in the zone) and a time can be set up.
Why do we have 2 Laser Cutters?
When the lasers were originally purchased, we received a huge discount by ordering multiple. (Three were actually ordered. The third is located with our friends, Sector67.) After the funds were raised for the actual purchase (via a kick-starter), one of our members contributed the funds necessary to purchase all three units. As a result, Bumblebee is owned by the space, Wolverine is owned by Roger S., and the third was purchased/is owned by Sector67 in Madison, Wisconsin.

TroubleShooting

When running TEST I get a SOFT STOP message on screen and no test.
That usually means your cut runs off the laser table. Check your origin point on the file and where you have the laser head starting. Sometimes it means that Logical Origin is set to ON which places your cut off the table, no matter where you have manually set the laser head.
How can I turn off Logical Origin?
To Cancel Logical Origin we will use the keys on the Control Panel on the Laser and the Control Panel Display.
  1. Hit ESC 3 times.
  2. Hit the RETURN key (the one with an arrow that goes down and to the left). This should highlight the current file name.
  3. Hit RETURN again. This should pop you to the Logical Origin screen.
  4. Hit Right Arrow until the field Cancel Logical Origin YES is highlighted.
  5. Hit RETURN.
My Test doesn't start where my laser head is and I have turned Logical Origin off
Make sure and check the IMMEDIATE box and save before Downloading AND turn off Logical Origin to allow the origin to be the manually set position of the laser head.
It takes several minutes or infinite minutes to compile in LaserCut
I have had this happen with some (but not all) DXF files from OpenSCAD. Open the dxf file in CorelDraw and then save it as dxf. It will "clean it up" and you compiles will now be very quick. I have no clue what is happening.
When cutting 1/8mdf through it takes 100% and slower than 20 speed.
Check Focus. If problem persists have trainer clean lens and mirrors. DO NOT attempt cleaning if you are NOT a trainer.