Laser commissioning / to do list
With the laser in and basically running, there is still more to do to get it ready for “production”.
I did the first pass beam alignment but did not check the exit beam at all 4 corners. Up to Mirror 3 it is good at all 4 corners. Near the center of the bed it is dead center on the nozzle.
To do in rough order:
- Connect laptop and configure LightBurn for the laser. LightBurn is the software for some design but more importantly editing of the engraving / cutting parameters for the drawings. Configured 10/31 – worked easily
- Check that the laser interlock for the chiller is functioning (chiller off, or disconnected, no water flow, etc) . Important not to destroy the tube. I know the flow sensor in the chiller works and triggers an alarm on the chiller but have not tested to make sure it is properly linked to the laser controls. I also need to find out if there is a flow / pressure sensor in the laser itself. — Works 10/31 both for chiller off and flow stopped. Check by trying to pulse and get water error if chiller is off or alarming – good.
- Upgrade Air Assist This will provide more air at the nozzle with adjustable pressure for cutting vs engraving and run off the shop air compressor rather than the tiny pump in the laser . — Started 11/1 I have enabled the “wind output ” on the controller in Lightburn and hooked up the pressure regulators and first solenoid to switch on high pressure. Waiting on a second solenoid and more 6mm hose to rework and have an air on / off from the status signal and have the low pressure reg hooked up to the first solenoid so I have have low and hig pressure plus off / standby. Note using the 6mm PU hose and push connectors is addictingly easy. I will be adding more for the milling machine, metal lathe and CNC router for the air and mist feeds and no more tripping over air hoses!
- Complete the exhaust pieces and hookup. One of the 2 hoses is connected, but the other needs a mounting plate made (perfect early project for the laser). Plus, I need to figure out a way to hold the exhaust hoses up as I push the laser back to the wall. –Completed 11/1 used the laser to cut the plywood panel to mount the duct flanges for the hoses. First “real” but simple project (not a test card or other test).
- Walk through the controller diagnostics and note all of the major signals and switches and where they are connected and the indicator lights for them. While the unit is basically working, get to know and document the “functioning” state for later troubleshooting.
- Get to the bottom of the intermittent “System protect” message and adjust the top door sensor. If you move the laser, it may trip the safety switch – Fixed 11/1 – lid left side proximity sensor needed to be moved out a bit. However now I need to add something to protect it if the door slams shut.
- Check bed level vs the laser nozzle. The distance from nozzle to bed needs to be constant across the entire area (4 corners and center minimum). — completed 10/31first pass. The corners are nearly dead on but the center of the honeycomb bed is low by about 2mm. This seems to be due to the frame of the honeycomb edge and the edge of the knife edge rack. These folded over edges raise the perimeter and then the center droops onto the knives. I need to figure out a solution
- Check size calibration . Run known size test pattern (e.g. 20x20cm) and measure to see if it is what is expected. — completed 10.31. This was done with the “sugar skulls ” test card. Size was almost perfect
- Check gantry for square. This is to make sure the X and Y motions are exactly perpendicular Basically engrave a large rectangle (same as above) and compare the diagonal measurements. They should be equal, otherwise 1 of the X axis bar pulleys / belts needs to be shifted. — completed 11/1. This was done with the “sugar skulls ” test card. Size was almost perfect / within measurement tolerance / error.
- Run more test cards for focus and power levels . Adjust autofocus if necessary. Test cards will be needed for each material type and thickness (basically build a library of settings). –Completed Drew and Ran a ramp test to find best focus. Test tool provided was quite close (20.5 vs 20mm) distance from nozzle to work piece. Autofocus sensor did need to be adjusted. It was about 6mm off. 11/1 so far I have done 2 different kinds of 1/4″ / 6mm plywood and MDF and 1/2″ plywood. I can foresee an ever growing pile of test cards as reference to complement my stain and finishing test cards.
- Automate starting of the chiller and exhaust blower — blower connected 11/3
- Label all of the warning lights
- Add more LED strip lights inside the laser
- Make a small dolly for the chiller. It is heavy and needs to be in the closet by the laser when not in use.
- Red dot pointer and beam combiner. Replace the existing red pointer with a coaxial one. This will be a fair bit of work as mirror 1 location is hard to get to and it will need to be replaced (or maybe locate after mirror 1???.
- Order spare mirrors and lenses. These are consumable items and with my great manual dexterity I will surely drop one and break it while cleaning at some point.
- Figure out what camera to get and where to mount it for use with Lightburn. This makes positioning of the stock easier vs the design to cut.
- Guard for Z axis chain to protect the internal vents. The vent hoses rub against the chain. New vent hoses were installed to replace the failed original “dryer vent type” hose but need protection. — Completed 11-3. Used boxes.py to do the test card and design for a finger jointed “box” which was really a tube . Ripped one side to make screw flanges and flipped them outside. Worked out well.
- Run scan offset tests and enter the offset values via lightburn. Note that this was not done initially and was performed later as part of the closed loop stepper upgrade, but it would have saved some grief by doing it up front.