Difference between revisions of "Laser Cutter - Bumblebee"

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A list of commonly asked questions
A list of commonly asked questions
1)  If I have a jpeg file, how do I etch it on a piece of acryllic?
2)  If I set speed on LaserCut, what does the SPEED % mean on the display of the LaserCutter?
3)  I have a jpeg of a line drawing.  How can I cut a piece of acryllic using that line drawing?
4)  Do I need training to use the LaserCutter?  If so, how do I get it?
5)  Why do we have 2 LaserCutters?

Revision as of 11:52, 28 April 2013

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
alt text
|175px| ]]
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.



Operation of the laser cutter must be done under the supervision of one of the trained operators.

i3Detroit asks that users donate $10 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 Settings

None yet

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

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?

2) If I set speed on LaserCut, what does the SPEED % mean on the display of the LaserCutter?

3) I have a jpeg of a line drawing. How can I cut a piece of acryllic using that line drawing?

4) Do I need training to use the LaserCutter? If so, how do I get it?

5) Why do we have 2 LaserCutters?


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.


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.