Difference between revisions of "Laser Maintenance Plan"

From Hitchin Hackspace
Jump to navigation Jump to search
Line 118: Line 118:
=Maintenance Record=
=Maintenance Record=


09/2015 - Adjusted gantry orthogonality. (Was wrong when delivered). PAB
* 09/2015 - Adjusted gantry orthogonality. (Was wrong when delivered). PAB
09/2015 - Adjusted bed so that is was level, (jack screw sync). (Was wrong when delivered). PAB
* 09/2015 - Adjusted bed so that is was level, (jack screw sync). (Was wrong when delivered). PAB
01/2016 - Cleaned all mirrors, and lens. Checked beam alignment (no change). PAB
* 01/2016 - Cleaned all mirrors, and lens. Checked beam alignment (no change). PAB

Revision as of 14:12, 25 April 2016

Laser maintenance

Focal lens

This is the lens that is used to focus the laser beam. This lens should be cleaned at least once per week. It is not possible to clean the lens while it is mounted in the focal tube. The laser beam alignment should be checked after cleaning is completed. If there is any incident of fire or large issue of smoke/fumes, then it is advised to check the lens and clean it. Use denatured alcohol and/or acetone as the cleaning solvent. Use a lens tissue or cotton tipped swabs (Qtips) to apply the solvent. Do not scrape the lens... Use the solvent to dissolve the dirt from the lens surface. Only use a soft swirling motion when applying the solvent. Use a dry swab in soft swirling motion while evaporating the solvent. Use as many swabs as needed to result in a clean lens surface. The lens surface should be somewhat difficult to see. Look at a reflection in the lens to help see dirt on the surface. Make sure to clean the lens and not leave water marks or dirt smears. The focal lens should be replaced if it is cracked, the coating is scratched/pitted, the core material is darkened, the coating is delaminating, or any other significant damage is found. Some minor blemishes are acceptable, but these problems waste power and will result in reduced laser power at the target material. Any dirt, contaminate, or damage to the lens will cause the lens to become damaged faster.


Mirror #3

This mirror is located directly above the focal lens. This mirror should be cleaned at least every one month. If there is any incident of fire or large issue of smoke/fumes, then it is advised to check the mirror and clean it. It is possible to clean the mirror in its' mounting bracket, but highly advised to remove the mirror from position and thoroughly clean it. The laser beam alignment should be checked after cleaning is completed. Use denatured alcohol and/or acetone as the cleaning solvent. Use a lens tissue or cotton tipped swabs (Qtips) to apply the solvent. Do not scrape the lens... Use the solvent to dissolve the dirt from the lens surface. Only use a soft swirling motion when applying the solvent. Use a dry swab in soft swirling motion while evaporating the solvent. Use as many swabs as needed to result in a clean surface. The mirror surface should be difficult to see. Look at a reflection in the mirror to help see dirt on the surface. Make sure to clean the lens and not leave water marks or dirt smears. The mirror should be replaced if it is pitted/scratched, rusted, discolored from heat damage, or any other significant damage is found. Some minor blemishes are acceptable, but these problems waste laser power and will result in reduced laser power at the target material. Any dirt, contaminate, or damage on the mirror will cause the mirror to become damaged faster.

Mirror #2

This mirror is located directly at the end of the gantry rail. This mirror should be cleaned at least every two months. Use the same directions as found for mirror#3

Mirror #1

This mirror is located directly in front of the laser tube. This mirror should be cleaned at least every three months. Use the same directions as found for mirror#3 Laser tube output coupler lens: This lens is located inside the output end of the laser tube. This lens should be cleaned at least every three months. You must be very careful when cleaning this lens. This lens cannot be removed from the laser tube. You can use a Q-tip for applying the acetone. Be gentle. The ideal situation is that you are only removing dust, film contaminate from humidity, or smoke fumes. Do not scratch this lens.. It is not replaceable.


Linear rails

The linear rails are the guiding rails along the left and right sides, and across the gantry. these rails should be clean, without rust, and have a slight glaze coating of some oil. The linear rails should be given some attention about every month. The surfaces of the metal should always have oil on it such that it is wet to the touch. The best way to see that you need to do some cleaning is to check the end of the rail near where the home switch is located. If you see a dirt line, then clean the rails off and apply fresh oil.


Linear bearings

The linear bearings are found under the gantry(to mount the gantry to the side rails) and under the focal head(to mount the focal head to the gantry). These bearings have grease fittings for pushing lubricant into the ball bearing areas. You might not have a special grease pump to lubricate the bearings. Try the cheap and easy approach. 1) Remove the grease fitting, 2) Apply the grease to your finger, 3) Push the grease into the little hole, 4) push more grease into the little hole, 5) go to step #2 ..... 6) Put the grease fitting back on.


Rubber belts

The rubber belts should be checked for appropriate tension at least every six months. You should expect the two side belts to be the same tension and should be tensioned at the same maintenance schedule. These side belts work together to move the gantry from front to rear. If one belt is tensioned more often than another, then that belt could become stretched more than the other. It is difficult to describe how tight the belts should be, but there should not be a slack, sagging, or flapping. If the belt appears to be worn on one side, check the bearing alignment or damage to the matching bearings. There are many laser machine designs, but the method of changing the belt tension should not be too complex. It is normally a method of tightening a screw and then applying a lock nut to keep the screw in place.


Fans

The cooling fans are used to force air over the electrical parts of the laser machine control system. If a fan blades get dirty, then that fan cannot move the air as quickly. We need to check the fans to see if our laser environment is not so clean as we hoped. If the fan blades are dirty, then we can clean the blades with a spray bottle of alcohol, q-tips, and some paper towels. It is best to clean fans with the power turned off.... Not spinning.


Jack screws

The jack screws are like threaded rods that are used to elevate the work surface. Most all laser machines have a work table that is motorized. The jack screws should be greased when assembled at the factory. Additional grease can be applied if desired, but is not likely to be needed more than every few years.


Chains

A chain is used to synchronize the turning of the jack screws. The chain will be woven from the Zaxis shaft around the sprockets at each of the jack screws. The chain should be greased when the laser machine was assembled at the factory. Additional grease can be applied if desired, but is not likely to be needed.


Nuts/bolts

check all connections on/around the lid and carrage are tight.


Coolant

Firstly, automotive antifreeze should not be used as a laser coolant. The best coolant is deionized water with a small amount of milton in it to reduce bio build up.. In the absence of deionized water, distilled water can be used. Tap water should be a much later resort. The coolant should always be clean and clear. It is a common problem for the coolant to become infested with mold. This often looks like a murky green water with snot building up on the inner walls of the hoses. The solution is a multi-step process.

  • Flush out the bad water
  • Add fresh water with 20 percent bleach . Cycle the bleach-water for 30 minutes. Flush this water out also.
  • Switch the inlet and outlet hoses and flush with more water. This should dislodge mold from inside the laser tube.
  • The flow safety sensor could also be full of mold... The best solution is to take it apart and clean with a soft

brush or pipe cleaners. Make sure to re-assemble the sensor correctly and without leaks. It is possible that harsh cleaners could creep into the sensor electronics and cause permanent damage

Spares

Maintenance Record

  • 09/2015 - Adjusted gantry orthogonality. (Was wrong when delivered). PAB
  • 09/2015 - Adjusted bed so that is was level, (jack screw sync). (Was wrong when delivered). PAB
  • 01/2016 - Cleaned all mirrors, and lens. Checked beam alignment (no change). PAB