Before we get started, it's important to make sure you've landed on the right cleaning tutorial. The Mr Beam II dreamcut can be identified by the brass tube for the air supply on top of the laserhead. Furthermore, it does not have the small [S] mark on the top right of the laser head cover.
1. Collect your tools
1: keyboard vacuum cleaner
2: filter mask
3: gauze compress
4: cotton swab
5: Allen-key 2 mm
6: safety glasses
7: glass cleaner
2. TAKE OUT THE LASER HEAD:
1. Switch off Mr Beam and plug it off. Allow the laser head to rest for at least 2 minutes before proceeding with the next step, to ensure that the laser unit is fully discharged.
2. If the laser head is in the Home Position of the working area, pull it into the centre by (a) gently moving the x-axis and (b) pulling the laser head into the middle. This way you will have a better grip of the laser head.
 |  |
3. Unscrew the laser head from the mounting bracket. Put the knurled nut back on the laser head body, this way you will avoid losing any parts during the cleaning process.
 |  |
4. On the back of the laser head you will find a black clamp which holds the white cable in place. Please pull it out carefully at the corners, about 2 mm. Unplug the cable in the back of the laser head by gently pulling it out.
 |  |
| Gently pull the air tube off the copper tube. |  |
3. Take laser head appart
1. Remove two screws on the back of the laser head, using a 2mm Allen key. Carefully take the laser head apart.
Tip: Take photos while taking your laser head apart! This way you will have a reliable memory aid later on, when putting the laser head back together again.
1: laser front
2: copper block and laser module
3 & 5: heat sink
4: fan
2. Carefully unplug the fan cables from the laser module. Make sure to get hold of the white pin jack, don’t pull on the entire socket or directly on the cables, or they might tear!
 |  |
4. Clean the laser head
Warning: Make sure to wear gloves while cleaning or wash your hands thoroughly at the end of the cleaning process. Please put on a filter mask and safety glasses, to prevent potentially dangerous substances and dirt from getting into your eyes or respiratory passages.
1. Heat sink:
Use a hand vacuum cleaner with a brush and clean all rilles as well as the recess for the laser channel thoroughly. 
2. Fan:
Vacuum off the dirt with a hand vacuum cleaner.
Important: Hold the fan wheel with one finger to prevent it from spinning while cleaning. Otherwise the fan will spin too fast from the vacuum cleaner’s air flow, and might break!
If there is a lot of resin on the fan, it is best to use a resin remover diluted with water to clean the filter with a cotton bud.
3. Laser module:
Vacuum off the dirt here as well.
4. Laser lens:
Wet one side of the cotton swab with a glass cleaner and carefully wipe the laser lens clean by making rotating movements with the swab. Use the other end of the swab to dry off the lens.
Please note: Make sure not to touch the laser lens after you have cleaned it. Otherwise you will need to repeat this step.
5. Laser front:
Vacuum off any dust particles. The laser front gets yellow and brown stains from cutting plywood. You can remove those easily by using a napkin and a glass cleaner to wipe the dirt off the laser front.
5. Assemble laser head
1. Plug the wires from the fan back into the socket on the laser module. It will only work in one position, but make sure the orientation of both parts matches.
2. Place the fan with a hole facing the top and align the fan with the metal pin. The product label in the middle of the fan should be facing the heat sink and should not be visible.
3. If it is not the case yet, screw the knurled nut on one side of the heat sink and then put both parts of the heat sink together. There should be no gaps between them.
Important: Make sure the fan cables are not squeezed between the both sides of the heat sink when they are put together! Make sure the heat sink closes tightly!
 WRONG - if the label on the fan is visible, it has been positioned in the wrong way |  WRONG - there should be no gaps between the cooling parts |
 WRONG - cables are jammed |  RIGHT - the fan's open side is facing upwards |
 RIGHT - cables are in the right position, in the notch of the cooling part |  RIGHT - cables are in the right position, cooling part without the notch |
4. Put the laser front back on the laser head. Align the position of white threads with female screw threads of the laser head. Press the laser head against the laser front and gently to the bottom. You will hear a clicking sound indicating you assembled it correctly. If it doesn't click, don't worry -sometimes it does not make this sound and is still correct!
Please note: Check that both rectangular holes pictured on the right are aligned to each other when the laser front snaps into place. There should be no overlapping which make the opening for the laser channel smaller.
5. Put both screws on the back of the laser head back in place using an Allen-key.
6. Now you can reinstall the laser head into the Mr. Beam. To do this, insert the cable with the contacts facing upwards into the black bracket and carefully clamp the bracket back in place.
Also put the tube back on the brass tube. Then screw the laser head to the mounting bracket in the Mr Beam.
In some cases, you may need to do a camera calibration after cleaning if the laser is not in the exact same position as before. So if you have a bigger offset than usual, you can find the camera calibration tutorial here. |  |
 |  |
DONE!