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  • Reonarudo 18:46 on 04/05/2011 Permalink | Reply
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    Acidifying it… 

    Hello,

    I’ve been really busy lately so thats why I haven’t posted as much.
    jheissjr made me notice that with so many experiments I didn’t actually etch any copper and that there was the possibility that the paint left some kind of residue that would prevent the copper from being etched.
    “Some people suggested residue is left on the copper after burning which prevents the copper from being etched.”
    So I grabbed on of my failed boards with the etched paint by the laser and threw it on the acid.

    So this was the result:

    I didn’t clean up the paint very well and some got into the etched tracks so here is a close up so you can see that it was really etched :)

    *EDIT*
    My flickr plugin broke with an update so I had to fix the pictures hope. Hope every thing is correct now :)

     

    • JL Arnal 17:53 on 22/01/2012 Permalink | Reply

      Hello !

      Nice work, but there’s something I don’t quite understand : you’re not using UV-sensitive varnish for your laser etchings, right ? So why bother keeping the KTP crystal of your laser, since you don’t need any UV component in its output ? Your laser seems powerful enough, but using the frequency doubler makes it waste 80% of its effective output power, lost in crystal parasitic heating and OC losses.
      And since even a cheap cell phone camera can make the IR spot visible, there wouldn’t be any trouble focusing the formentioned IR beam .

      What do you think ? ^w^

      • Reonarudo 04:23 on 24/01/2012 Permalink | Reply

        This is a laser diode and to tamper with anything I would have to damage the casing and risk to damage it. There is no reason in using that wavelength it was just the best power/price laser diode I found. For this experiment the wavelength doesn’t mater since I use a black paint but in other cases you should take into account if the target material will absorb the wavelength your are using.

    • kenwshmt 23:15 on 08/02/2012 Permalink | Reply

      I like your work.
      I am tinkering with making a mount similar in function to what you have on that one for a printrbot, which is a Mendel variation. on the side of the printer head.
      can I ask a few basic questions? you are a year furtur along in this than I am.
      http://www.printrbottalk.com/forum/viewtopic.php?f=21&t=162

      • Reonarudo 13:28 on 09/02/2012 Permalink | Reply

        Sure you can ask anything. My laser experiments have diverged from laser engraving to sintering. Some posts on that might come soon.

    • kenwshmt 02:17 on 10/02/2012 Permalink | Reply

      I’m exploring the sintering as well. I’m trying for basic cutting for papercraft and to have it on the head all the time. How did you get the power to switch from the computer? opticoupler? relay?. and what are you using for the laser power supply? I’ve gotten a cheap 1 watt IR in the same casing as you have, but I’m not going to power it until I’m certain I won’t burn it out. the specs on a printrbot control board haven’t been released,so i cant design for that yet.. but what did you do for yours for computer control?.. As terse or concise as you like, I’m still 2 months from having anything to attach it to. :P

      • Reonarudo 13:58 on 10/02/2012 Permalink | Reply

        What I use for control is a normal GCode generator that you can read about in some older post. The power comes from the Gen6 board where I use the extruder heating connector (12V) to power the laser and the laser power circuit is also mention in another another post but now I know there are much better (healthier for the diode) approaches but I haven’t tried them yet.
        “I’m still 2 months from having anything to attach it to”
        I know the feeling… too well unfortunately… I would recommend to look into laser diode powering circuits now and after you understand them use one that fits your needs or design your own if you feel capable of and give if a simple on/off signal interface so you can connected it easily with any controlling board. Don’t depend on the printrbot control board because it might not be enough for you needs hence do something the most generic you can.
        I’m interested in knowing how is your sintering development, do you have any information about your approach?

    • kenwshmt 13:55 on 11/02/2012 Permalink | Reply

      I’ve been wondering: if a layer or two is printed normally, then the laser runs around the outside line of the extrusion, does it affect the finishing at all? it might be an (impractical) way of doing some on the machine post processing. I’m curious what it looks like, or if it works at all. it might be useful to control the cooling of any particular piece of printing, though natural hinges need faster cooling not slower.

      • Reonarudo 15:58 on 11/02/2012 Permalink | Reply

        I’m not sure I understood the context.
        If the laser runs outside where he should be it should be turned off, there is no reason to keep it on the effort to control this is so minimal that it should be done and keep quality even if the decrease in quality would be insignificant. During print you should actually increase temperature so the fusing point is reached faster. Hinges?
        I hope my answers helped because I really am not sure of the context here. Cutting? Sintering? FDM?

    • kenwshmt 17:46 on 11/02/2012 Permalink | Reply

      just wondering about using the laser for modifying an existing print as its being made. as in, it may be usable for insuring internal holes and edges are sharp in what would be an enclosed object when its finished printing. if its on the head, might as well put it to use.

      • Reonarudo 18:05 on 11/02/2012 Permalink | Reply

        I don’t believe it would work very well. Maybe melting the external surface to look more smooth but I’m not sure how that can be achieved. Usually a well calibrated printer won’t have problems insuring holes and if we would use a laser for that it would need a really high angle focus so it would only modify the desired layer. Anyways even if I say that its unlikely the best way is to try it for yourself. ;) Don’t forget to have printing material into account.

    • kenwshmt 08:06 on 09/09/2012 Permalink | Reply

      http://www.thingiverse.com/thing:30064

      Thanks for the inspiration.
      All I need to do now is make a 12 volt to low TTL signal adaptor to use the fan line for on / off control.

      • Reonarudo 13:55 on 09/09/2012 Permalink | Reply

        A pleasure. I’m building a printrbot myself so this will be a nice addition. :)

        what electronics are you using?

        • kenwshmt 15:02 on 09/09/2012 Permalink | Reply

          I haven’t made the control adapter for it yet, but I will optocouple off the fan power line. I’m not using any power from the printrboard. The Laser came with a driver board and heat sink which has TTL control.

  • Reonarudo 01:17 on 12/02/2011 Permalink | Reply
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    Trying to fix precision… 

    Hello,

    This time I’m just trying to fix the machine so it can output properly the models.

    If you have read the previous post you know that I’m having problems with circles. From what I have read on the net the problem is called backlash. Other people had the same problem in the past. One of the solutions is to tight the belts but if you have read the previous posts you know I already did this and when I rotate the gear manually the carriage responds accordingly.

    So to start I got someway to debug the thing several concentrical circles:

    And it came out like this:

    Ok this definitely shows the problem with circles…

    I lubricated the bearings and the X axis smooth rods to diminish the friction as suggested by nophead in the reprap forum.

    The result didn’t change at all. This can be because the problem in on the Y axis or it is something else on the X axis like the gears not fitting properly with the belt. I haven’t replaced the old gears that are glued with hot glue yet  so if the problem is from this I have a good solution now that I have replacements.

    This was the result of the lubricated X axis on a red tape.

    In this picture is clearly visible that circles are broken in the top  suggesting that there is at least one problem in the X axis and that I will probably have to change the gear that I’m using or increase the motor current.

    I tried everything and printed several tests none of them produced any diferences in the result.

    And now after a day of tests I present all my tests results and an acceptable end result (nº 15). :)

    Conclusion: The X axis is pretty sensible and the Y axis belt has its teeth against bearings and that causes variations in tension while printing it should be revised. For the X axis I basically remount it having attention to every little detail and check if the Z axis is correct and not interfering with the X axis. So after all this testing it is time to re etch the circuit…

    So it was a good improvement and the circuit was almost usable, but I guess my mendel X axis isn’t good enough. Maybe someone out there in the community can shed some ideas how to improve this because I’m out of them. :(

    I’d probably only get better results with a completely new X axis and for that to happen I have to receive my hot-ends first…

     

    • Ken Jenkins 20:46 on 08/06/2012 Permalink | Reply

      I read a write up on what you are doing over on hack-a-day. I’m interested in the process. I have a commercial laser system so that part of it and the “motion control issues” are not a problem. I’m not exactly clear about the process you are using. ie. are you “getting rid of the non-trace copper by oblating it with the laser” or are you “getting rid of the black paint in the non-trace area so that the etchant can eat the copper in a second step.” Thanks. Very interesting approach.

      • Reonarudo 21:43 on 08/06/2012 Permalink | Reply

        Exactly. The laser oblates the paint where I want the etchant to reach, it is faster if you only oblate the outline of the traces.

  • Reonarudo 03:43 on 09/02/2011 Permalink | Reply
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    Round 3 

    Hi,

    I’m still waiting for my hot end parts to arrive. But at least I got new pulleys for free at AltLab :) I’m sure my mendel will appreciate them.

    Today I regenerated the GCode with CAD.PY with new settings:

    After that I had to edit the GCode manually in a text editor so that the mendel can use it to make the etching.

    After all the editing I load it up in Repsnapper that gave me a nice preview of what it would be done.

    I added 3 cooling fans to the mendel (it can almost fly now :D ) to keep the circuit and the laser cool and it seems it worked. Ate least this time it didn’t auto destruct from the laser heating and helps keeping the smoke away from the lens.

    Here is a clip of the machine working

    Circuit etching with laser on reprap mendel

    The results where quite promising but it seems the mendel still needs calibration.

    As you can see in the bottom there are some tracks that are suposed to be round connected to a via but they came out all distorted and still have no idea how to correct this. If you know anything or think of anything that can help please drop a line in the comments. Also I obviously made the tracks to thick but that is easily correctable in cad.py.

    bill2or3 from the RepRap IRC Channel sugest that I use a heated bed it seemed a good idea and I implemented it but I don’t know why it suddenly stopped heating and I gave up on it for now.

    I don’t think I’ll drop this iteration on the acid yet but probably the next one who knows. ;)

     

  • Reonarudo 00:18 on 02/02/2011 Permalink | Reply
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    Round 2 

    Hello every one who has been following my short adventure to build a self replicating robot able to kil humans with lasers, hmm, oh forget that last bit…

    Ok, I have a very limited number of PCBs available for tests so I had to wash the paint of the previous PCB with acetone. It came out very easily.

    This time the paint coat came out a little bit more uniform than the first time. Maybe I should try some graffiti art next time :D .

    I modified the cad.py setting to completely fill the outer part of the tracks. This would be a lot slower but it would increase the number of things tested to guarantee that I cover all the bases.

    So I sent the board under the laser one more time and this time it was much slower. As a consequence the laser and the driver heated a lot more, that is definitely not good and I had to interrupt the print.

    I tried to improvise a fan with a CD and a motor but it just came to be an epic fail and I ended with a cut in the tip of my finger from the improvised blade.

    So I packed the LM317 from the driver circuit with a bunch of dissipators and hoped for the best…

    Ok I crossed my fingers and tried to print again.

    I t was working… for about 15min (I wasn’t counting) then the hot glue that was holding the laser melted from the heat.

    Even so in that short time I got improvements! The laser etched the paint and reached the copper :D .

    It is not very perceptible in the photo maybe check the flickr if you can’t see the copper.

    I HAZ COPPER!

    I definitely have to get a PC fan to cool things down or else I will not be able to continue development. But today’s results are very promising.

    It’s good that I can’t go much further right now because I have to study for a final exam that I have thursday.

    Stay tunned.

     

  • Reonarudo 01:01 on 01/02/2011 Permalink | Reply
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    PCB laser etching round 1 

    Hello and welcome,

    This time for something more interesting. Yesterday I started my PCB laser etching tests as Casainho requested.

    First I started by spraying the PCB with a random Black Spray Paint I got from the local Supermarket. It could have been red since red doesn’t reflect blue but the black one was cheaper. Attention this is a matte black! We don’t want our laser beams shining everywhere.

    I painted the PCB and it didn’t look great, it had some cotton in one of the corners and some bubbles, but it looked awesome for the first time I ever used a spray paint :D .

    For the laser etching I had been using comercial software and that wasn’t very Reprap like so I found CAD.PY this software that is used by some other people in the 3D Printing community to etch PCBs and it was perfect for this application. After some tries I managed to generate a usable. First I had to change the units to mm and cad.py is in inches so I asked my friend Google what value should I use. The rest of the parameters I used the same logic and some experimentation then after generating the GCode I still had to change it manually to have in account that we are using a laser and since the laser is connected to the hotend heat I just had to change Z changes for M104 commands to turn on and off the laser.

    First try to laser etch pcb #1

    It looked great working, unfortunatly as usual I had some problems that messed up the etching completly.

    The axis belts where to loose and lhe lines ended very fine but they where all wrong and wobbly.

    I did something wrong in the GCode because the laser was moving to fast and it wasn’t getting deep enough to reach the PCB in most of the circuit.

    I hope to have better news in the next post. Stay tunned ;)

     

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