Our 1390LC Laser Cutter

  • So, we have 65 hours on the laser since I installed the meter.

    @Vaughn told me he cleaned the lenses in the last couple of days, so I got Jerid to swap out the furnace filter and vacuum out the filter enclosure.

    I tried to fix the x-axis belt alignment issue, to no avail. It looks like the holes were drilled slightly off at the factory and it just took us a while to notice the wear on the belt. In order to compensate, we are going to have to make a mounting plate that gives us control of the pulley angle. Either that or resign ourselves to replacing the belt occasionally, and having spares in stock.

    I confirmed that when you move the Z-axis, the laser dot still drifts down and to the left. Alignment is better than it was at its worst, but is still off. Also the laser, when in focus is not round at all:


    I dropped the bed about an inch and a half between shots. The two hits should have nearly co-witnessed but the beam drifts as it moves down. Also, the close hit beam should have been perfectly circular. Initially I thought maybe the beam was hitting the inside of the lens tube. But this shot makes it clear that it is not hitting near the center of the mirror at all:


    That circle is me rubbing my greasy thumb on the paper and outlining where the hole that goes into the lenses is. Documentation I’m seeing online indicates that we need to hit within 2mm of the center of that circle everywhere on the bed. As it is, we are just clipping the edge of the circle, losing some of our beam, and getting the strongest part of the beam to hit the edge of the lens, which is likely curving it off center.

    About 8 minutes 20 seconds into this video is a pretty good description of how to systematically remove the error from your laser alignment.

    Unless someone comes up with a better suggested procedure, I’m going to try to follow those instructions. @arasbm @Nicholas @MIPS anyone else have suggestions?

    Also, I’ve created a very simple form for logging laser cutter maintenance:

    It just saves info to a spreadsheet in google drive for now. I’d like to capture how many hours before various things need doing so we can start to predict issues. I’ll eventually build it out into `a proper maintenance application with a database backend, but this will do for now. If you do work on the laser, or replace any bits, please use the form to make it easy to track. I’ll try to put it on the desktop on the laser-cutting machine.

  • I did some cutting yesterday afternoon. 3 things:

    1. it’s generally cutting more vertically than when I used it a few weeks ago, eg, my cuts didn’t have a slope to them.
    2. before I started, the bed was not nearly high enough, and the bed was bowed upwards, eg “concave”. It seems the back of the bed was caught on the frame, so I lowered it down and pulled the bed forward, at which point it moved freely, and came up high enough to focus properly.
    3. it looks like the laser is out of alignment when cutting on the forward right corner (towards the control panel) like the laser is diffracted inside the tube and cutting two lines. I noticed this on a few pieces. I’ll see if I can find a sample to get a picture of.

  • I also noticed today, the laser doesn’t look like it’s coming out of the center of the tube at all :(0_1493604223202_20170430_163855.jpg

  • Design Lab

    We should plan a Laser Servicing Party soon! Maybe @arasbm and @pierre and anyone else interested can meet (Hack Night?) and address the alignment.

    I am concerned the laser is hitting the inner housing of the lens enclosure and may be damaging the part!

    One thing to note: when the honey comb is taken out and replaced for cutting on the rails, the honey comb has to be properly aligned on the rails or it can catch under the blue surround! That may even be the cause of the bad being out of alignment with the gantry/laser.

  • I will be there on Thursday for the first aid workshop, after I will inspect the laser and report back.

  • I’m interested in learning as well. Happy to learn the procedures and document maintenance done in the log.

  • Watching this today. Will not attempt the procedure without the assistance of someone who has done it before.

  • @Vaughn The laser has not got nearly the power to damage the aluminum tube. Not by several orders of magnitude. I wish we had that problem, because then we’d be able to cut and engrave metal.

    It’ll mark the anodized coating if it is in focus when it hits it though, which might tell us if we are hitting the edge of the tube after we exit the last lens.

    Beam is about 8mm in diameter before it hits the last mirror so the energy concentration is considerably lower than it is after the lenses. It barely sets paper on fire on a full power pulse. If I could get a decent filter that gave me about 10% IR transmission, we could probably see interesting things by burning paper with the unfocused beam.

  • so @pierre and I did a quick inspection today after the workshop. The laser is out of alignment. It also not hitting in a round circle shape as you would expect. This may be due to damages mirror or lens, or hitting side of one of the mirrors on the way. We need to set a few hours aside and do a full inspection and realignment of the mirrors.

    I do not think it is unsafe to continue to use the laser for now, however you may notice reduce cut quality.

  • Laser is down again. Tube is broken this time. As you can see here in glorious potato-vision (trying to get my phone to focus on the inner tube instead of reflections off the outer was not cool. Somebody needs to design a manual-focus cell-phone.


    The metal terminal (Not sure if it is cathode or anode, but I suspect cathode, because it is serviced by a tiny-uninsulated black wire… the other end has high-voltage insulation) at the business end of the laser has broken off the inner glass tube (The spring noise that @Krankin heard) and there is now water in what was the sealed CO2 chamber.

    My reading indicates that you get about 1000-2000 hours of cutting time out of such a tube, and I need to check the hour meter again, but I think it has put in over 300 hours in the last 4 months. So we likely just used it up. Next time we’ll hopefully have warning well before the tube hits end of life and have a replacement in hand when the time comes.

    I’m shopping around for a replacement 120w CO2 laser tube now. We’ll fund-raise for it when we have a good idea of the shipped cost. It’ll likely take at least a week to get the new tube, so I was talking to @Grant-Fraser about rebuilding the chiller with easier water changes and better filtration while it is down. @Vaughn was bending my ear about setting up an interlock so you cannot fire the laser with the chiller offline too. Ideally such a system would measure flow and temperature of the supply-side water, rather than just “make sure it is turned on” so that it will throw an error and refuse to fire when the pump fails.

  • Member

    @pierre RIP laser tube. You served us well

  • We should have over 100$ credit with G-Weike toward the purchase of a new laser tube. I strongly recommend going with the manufacturer because so far they have given us stuff that works really well for very cheap and their support has been decent too. @kile was last in touch with them over the info@kamloopsmakerspace.com email before I hand over the email to makerspace. Please look at last conversation in there with G-Weike about ordering a laser tube.

    The danger with ordering a cheap tube from some random supplier is that we have no assurance that it was not sitting on a shelf for the last 5 years. The laser tubes have limitted shelf life and they would fail much faster if they have been stored for too long. At least G-Weike seems interested in us referring them to other potential customers, so chances are they will act in our best interest.

    Regarding the flow sensor, there is a flow sensor in line with the water tube. I do not know how it works and if it does work, but I would look at that first before implementing additional security for monitoring water flow. It might be working perfectly fine.

    Good luck with finding a new tube. I will wait for someone to start a fundraising thread, but I will chip in 100$ toward a new tube, whichever you decide on.

  • Classroom

    The offer to info was $100 credit IF the guy I talked to about our laser ended up buying a laser from them. I am not sure if he did or not, but either way I agree with @arasbm, the manufacturer is probably the way to go. From the sounds of it our tube performed to (or above) spec in terms of hours. It will be nice to track the hours on the new one from the start.

  • Design Lab

    I’ll chip in $100.

    Does G-Weike carry the rotary tool for the laser? If so, how much is that?

    The Clay Space grant does include that tool as a line item. We need to have the capability in place for the Clay Space programme launch Sept 1.

    @pierre mentioned he could make one, but with all he has to do I think researching an off the shelf model is a good idea.

  • Member

    What kind of cost are we looking at? Should we do some sort of fundraiser?

  • Classroom

    I have contacted G.Weike for a quote on replacing the tube. No response yet.

    I have also requested a price on their rotary tool as per @Vaughn’s request.

    @arasbm also mentioned it might be a worthwhile time to ask them about the cost of components to upgrade to a 300W tube, I am assuming that this would also require a new power supply, and possibly other components (I have no idea). I will ask then when I hear back.

  • Classroom

    @pierre said:

    Somebody needs to design a manual-focus cell-phone.

    My new LG G6 Android phone ships with a built-in manual focus option on the OEM camera app. I would be surprised if you can’t find an android app that will give digital manual focus capabilities to most android phones. The Lumia 1020 has a 41MP camera, and I’m pretty sure it has true optical zoom and focus capabilities (but it is a Windows phone, ewwwww).

  • @kile said:

    @arasbm also mentioned it might be a worthwhile time to ask them about the cost of components to upgrade to a 300W tube, I am assuming that this would also require a new power supply, and possibly other components (I have no idea). I will ask then when I hear back.

    The 300W tube I’ve been drooling over online uses two smaller tubes, the first pumps the second… Two 150W tubes, two 150W power supplies. They have a 3-barrel, 3-tube 400W rig too. I’m not sure I could shoehorn that into our machine though.

    I also tried contacting G-Weike with no response. I’ve put in requests for quotes from several suppliers, but have not got an answer yet. This weekend, I’m going to try to find and contact the company that @trunner has mentioned that has given him very good service in the past.

  • Classroom

    Okay so I got a response from G.Weike. Here it is:

    Hello Kile,

    Good day.

    1. Checked the record, you are using RECI W4 tube, best price $ 435 / PC.

    But the freight cost by DHL is high.

    Do you have any other goods buy from China? So we can send together?
    Or your friends buy from China?
    Cheap & Safe way by Sea.

    1. According to your order, auto up-down table equipped, so Rotary axis is available
      But there is no interface to connect the rotary axis. Can you add this?
      Rotary axis old type $ 200 / PC, Rotary new type % 250 / PC.


    Emily Cheng
    Sales manager
    ADD: C-504, In hi Tech square High-Tech Zone, Jinan, Shandong, China
    Tel: +86 0531 88020976
    Mob / Whatsapp: 008618905413376 Skype: G.Weike Emily Cheng
    Web: www.gwklaser.com www.wklaser.com

    Doesn’t say how much shipping would be, just “high”. I have requested a specific quote.

  • I looked up the laser tube on aliexopress. Shipping is usually just over $500. Return airfare to hong kong is $1000

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