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Razanur

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  • 3D printer
    Ultimaker 2+
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    NL
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  1. Thanks a lot - that helps! Do you reccon, one could drill the heater hole to 6mm?
  2. Thank you for the tip! Actually just doing a regular internet search for "Taobao agent" several website pop up. So far I'm pretty happy with http://bhiner.com - you can simply copy and paste the urls in their search bar. With all the required parts from Taobao I end up with around 53€ (don't know if there is additional shipping costs). I'll edit this post when I ordered and tell you how it goes. BTW: which diametres and lengths are the heater elements and PT100 for these heating blocks?
  3. Hi, sorry for zombie-ing this thread, but it is one of the first search results and very informative. There is a new option available: This seems to avoid the hitting and the loss of printarea problem. Only the sourcing of the materials seem to be hard. How do you think this compares to the aformentioned two?
  4. First: I think you did something amazing and I probably want to go in a similar direction. I just wanted to add my personal views/perceptions on some points, maybe also for the benefit of people reading this in the future. That is pretty neat! I think it might not be suitable for the big, heavy laser I'm using though. That is a very valid argument. However, with more power you can also cut, engrave etc. I'm not sure, how much power is exactly required to remove the paint. As far as I can tell, there is no proximity effect whatsoever for the spray paint method, where I would expect a small a proximity effect in the photo-resist solution (the resist is transparent, so reflections from the copper also develop nearby resist). So from theory, but also from the results I've achieved so far, I don't think there is much of a difference. I think both techniques have their strong and weak sides. Since most (all) PCB design softwares use-defacto vector descriptions to begin with, I don't really see your point here to why it would yield higher resolutions. Also, there is a well-working plugin for eagle to produce nice gcode files already. For pictures with shading etc, I think you totally have a point. Hmmm, it appears you have a very different beam geometry than I do. My beam is currently rectangular with one side about 3x longer than the other. As I said, I think it is much easier to compensate for weird dot geometries in the raster/pixel scheme. The only way to compensate is to use a pinhole (which especially for low power (150mW) should be no problem whatsoever (albeit extra work)). I don't really understand how rotation and defocus can make a gaussian profile out of a non-gaussian profile. Could you maybe explain this a bit further? If you really have a gaussian profile you have a very valid point. However, in my case my beam is a pretty well defined rectangle, so this is not an issue. Also for PCBs you basically only want discrete paint removed/not removed. As my beam is currently smaller than the apparent step size of the UM2, this does not seem an issue to me. Again, if you want shadings etc, go pixel ? I did a few test patterns and with speeds of ≤ 300mm/s, I see no residual ringing whatsoever. Also check the picture I appended: I think it is high-res enough, that you should be able to specifically point out any artifacts - and I don't see any oscillations. I think this is advantage no 2 of the vector approach; its much faster and potentially uses less etchant. Advantage no 1 being, that you can implement is much easier for beginners/as a first test and cheapter (unplug fan, plug-in laser, extract gcode from eagle, replace a few commands, run). That's super nice. I think I should also go with the exp-port and introducing the 'B1' command. Does this port also support PWM directly? I would like to set the laser power from the gcode directly for the vector mode (as you then only have to update the gcode on the SD card, nothing else). Well, you could use the FAN output as sync. Otherwise, I totally agree. I would also go with an external controller. In the case of vector mode, I would just forward the PWM signal (either from the ext or the FAN) from the main board. That's good to hear! I would definitely love to see a write-up and some pictures of your rig! I'll try and see if I can drill the holes by cutting them out with the laser, but I'm still a bit sceptical about that.
  5. Hi conny_g, I've also just upgraded my UM2 with laser cutting/etching capabilities (405nm laser, several Watts of power, mounted with https://www.thingiverse.com/thing:3022126). I followed a quite different approach though for PCB mask etching. I'm using the print-head cooling fan PWM to directly control the laser power output. Then I create a gcode file, tracing the outlines of the PCB layout (through eagle ULM). In my case, I'm not using photosensitive film (as I think you do), but a plain PCB, spray-painted in black and then blasted away where I want to etch (so also effectively using positive resist). I'm also getting a 0.09mm (better-than 4mil) resolution with that. I think I'm mostly limited by the step-size of the UM2 and the 3:1 rectangular beam profile. Working on adding a pinhole in the beam to get a round beam profile (not sure how well that'll work). Using paint rather then resist also allows me to just remove the paint if something went wrong, re-paint it and try again. This is very easy to build and yields great results fast, so I would suggest to you to use this technique for PCBs (with your low laser-power maybe still with photo-resist, rather than paint though). As you already figured out however, gcode doesn't really support drawing shaded bitmaps (and it is hard to hatch larger areas with a 0.09mm beam). So I might still be interested in developing the solution you proposed. It could also be better suited to cope with the non-square beam profiles that we often see in diode lasers. One solution would be to use rectangular instead of square pixels, another to move adjust the write time for each pixel such, that it effectively becomes square (which would lower the resolution a bit, limited by the longer side of the beam). Ideally, we could merge the two approaches and build one controller that can run in either mode without having to switch stuff around. This might be possible if we used the fan PWM to give the sync signal, which can then be send from the gcode. As a bonus, the firmware-modification would be unecessary. Let me know what you think, maybe contact me via PM.
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