Difference between revisions of "Laser Cutter - Bumblebee"

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[[Category:Laser Cutter]]

Revision as of 12:31, 25 February 2014

There are two of these. They have 3'x4' beds and 150 watt tubes. This one is named Bumblebee. It is identical to Wolverine, except that whereas Bumblebee is yellow and black, Wolverine is yellow and very dark navy blue.

Laser Cutter - Bumblebee
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Name Bumblebee
Owner Group-owned, purchased with funds collected from far and wide.
Make Model Jinan G. Weike / WKLaser LC1280
Part Number
Date Acquired
Storage Location West wall, you can't miss it.
Authorization Required
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.

There is also Laser Cutting for Dummies on our wiki.

Other References http://boxmaker.rahulbotics.com/ makes wonderful box patterns that you can put into the laser cutter.



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.

Do not cut or etch any plastics or other materials that contain chlorine or vinyl. A trace amount of chlorine, such as found in the glue in thin plywood or the resin of medium density fiberboard, is acceptable. Particle board has too much glue. You are responsible to know whether there is chlorine in your material before you try to cut it.

If you cut plexiglass, please be sure that it is acrylic and not polycarbonate. Look along the cut edge of the material, from the side. Polycarbonate is dark on this area; acrylic is light. Polycarbonate is one of the most dangerous materials you could try to laser. It instantly starts producing yellow, acrid, toxic fumes which will corrode your lungs, and the mechanisms and lens of the laser. When the lens clouds up with these fumes, it may reflect the laser back into the machine, which may melt the head and set the machine on fire. You may not be able to reach the fire extinguisher due to what is in your lungs. Both these outcomes will upset the community.

Materials List

  • Cut or etch: Acrylic, Delrin, Leather, Matte Board Chip Board (AKA architect modeling board), Melamine, Model Foam, Rubber, Wood (natural or veneer)
  • Etches but does not successfully cut: Glass, Coated Metals, Painted Metals, Ceramic, Tile, Marble
  • Cuts but does not take etching very well: Cloth, Paper, Mylar
  • Banned: Human flesh (yes, this has come up), Polycarbonate (Lexan etc.), PVC, Particle Board, any plastic if you don't know for sure it is Delrin or Acrylic


Get material that will fit on the bed of the laser cutter, which is 3'x4': 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.

You will need access to vector graphics software to design your parts. So far, DXF files seem to work the least-bad of the various vector filetypes, so use them. LaserCut is good for putting finished art into the laser, but barely adequate for designing art.

Materials which can be cut, can normally be cut up to about 3/16 of an inch. Some materials can be cut thicker with multiple passes. The thickest cut so far was of 1" thick acrylic. However, that required that it be cut from the opposite side, while flipped over and perfectly registered.

When cutting parts on the laser, you will use the software to set the cutting speed and power. If we have cut the material you are using before, you can refer to the power and speed recommendations in this list. Otherwise - experiment! Bring some scrap material to do test cuts on until you find a cut you are satisfied with. After that, record your power and speed settings in the list:

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 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

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

In general:

  • Lower speeds allow for lower cutting power, which saves life on the laser tube.
  • Lower speeds cut a wider "kerf" (thickness of cut) through the material.
  • At higher speeds the cut is faster but requires higher power, which uses up the laser tube faster.
  • High power on wood and paper may cause some discoloration near the cuts (browning color from burned material).

Time-of-cut checklist:

  1. Place material (square to edge of honeycomb).
  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. Turn keyswitch to on, and wait for boot and home to complete.
  7. With the D-pad, jog head over to center of material.
  8. Press "Z" to enter the mode to raise or lower the bed.
  9. Keep one hand over emergency-stop. Press "Datum" to auto-focus.
  10. Press "Z" again to exit Z mode.
  11. Wave hand under head and verify that air-assist is blowing.
  12. Download design from LaserCut software.
  13. With the D-pad, jog head to start of cut.
  14. Keep one hand over emergency-stop while using the "Test" button to check boundaries.
  15. Turn on the exhaust fan (black switchbox on wall).
  16. Lift the fire extinguisher and set it back down. This verifies that your muscle-memory knows where it is.
  17. Press "Start".
  18. DO NOT WALK AWAY. See http://www.thinkhaus.org/2011/04/03/lazzoring-is-serious-business/ for why.
  19. When cutter finishes, observe elapsed time on LCD and put money into box.
  20. Also, please remember to turn off the exhaust blower! The furnaces have to put back everything it removes.

Maintenance Info

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 lens cylinder has telescoped in itself, because the thumb screw that forms its lip was loosened, so calibration is done by pushing it back in place and re-tightening it; or, B. the depth-finding plunger is at the wrong height on the lens cylinder.

Regardless of which of those parts you are adjusting, use the huge acrylic brick which is on the shelves to measure your success and determine whether to go up or down. Put the block under the laser, do an auto-focus, and mash the "Laser" button for several seconds. The resulting hole will get thinner as it goes down, and then thicken out. This matches the shape of the beam. When the narrowest point of the hole (where the beam is most concentrated) is as close to the surface of the acrylic block as possible, this means the auto-focus plunger is at the correct height.

If you are not telescoping the actual lens cylinder itself, you will adjust the bracket that connects the auto-focus plunger to the lens cylinder. The bracket tightens on both ends, where it grips both those things. Ideally you would move the bracket where it grips the lens cylinder, not where it grips the plunger. But at the moment (April 2013), the clear plastic screws that tighten the bracket on the lens cylinder have their heads broken off from use. Roger is finding replacements for them. In the meantime, use the hex wrench in the white plastic tub to loosen the screw in the bracket which holds in the plunger.

Gently twist the plunger and pull up or down to adjust its elevation within the bracket. This twist will keep it from jumping up or down farther than you intend to. You'll probably want to just barely nudge it up or down. Then tighten the bracket and burn another focus hole. Repeat until the narrowest part of the hole is at the surface of the block.


A list of commonly asked questions

1) 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.

2) 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.

3) 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.

4) 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.

5) 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.

How To

How to cut PCB solderpaste stencils


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.

That should do it.

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.

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.


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.


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.