Selective Laser Sintering.



  • I was talking to a guy in Vancouver who designs and paints 3D models for board-gaming… He draws them on the computer, sends them off to ShapeWays and has them SLS printed in fine powdered nylon. I picked up one of his cheaper ones, unpainted, to use as a demo of what the technology can do…

    0_1470675660296_battletech-01-full.JPG

    Here are a couple of close-up macro shots of the thing to give a good idea of the resolution:

    0_1470675897670_battletech-02-foot.JPG

    Notice the undercuts:
    0_1470675946724_battletech-03-chest.JPG

    The SLS system lays down a very thin layer of powder, then uses a very precise laser XY setup to scan the surface and weld powder to the layer below, then drops the bed and lays down another very fine layer… This means that the part is fully supported during the entire print. You never need to bridge an open area. You just clean off and re-use the unwelded powder support material afterwards. (It also means that you can’t print a fully enclosed hollow space though… it’d seal the powder inside.)

    Anyway, I was thinking that we have a very precise, large format laser x-y table… If there was a z-stage that contained a suitable powder distribution system that you could just drop onto the laser cutter and start printing, it might be a fun toy. I did a little looking online and found this:

    http://reprap.org/wiki/OpenSLS

    Interestingly it will print in wax powder… which opens up a world of interesting lost-wax casting options.



  • I am pretty sure @BrianB at scorpion has one of these printers. I have been very impressed with the demo pieces I have seen.

    I personally would be more interested in building a resin based printer. Something similar to peachy printer which can provide high enough resolution to create jewelries. Either way, I think this type of printers can be built whit much less powerful laser. Our laser machine would be overkill, and with the amount of use we are getting out of our laser, I rather not interfere with its normal operation at all.

    It would be nice to create a different type of printer (not based on extruding filament) from scratch that can print very high resolution parts.



  • My reading says that our laser is overkill, but also that a CO2 laser is far preferable to a diode laser because of the frequency bands that it runs in (only black plastic is not transparent to most diode lasers…) The other factor that makes me want to start with an SLS module that fits our laser is an attempt to do a feasibility study… I’d want to start with the simplest proof of concept that bolts onto our existing gear that I can, then add features to make it into a standalone unit as time permits. That way if we decide that we cannot build a reliable powder distribution system we are not stuck with a spare (expensive/bulky) underpowered laser cutter.

    In an ideal world, I’d build two powder stages, one sized for our laser cutter (think printing enormous parts…) and a much smaller one for printing more reasonably sized parts, and use that one as the basis for a future stand-alone machine.

    Much as I love the peachy printer concept, sintering powder is a much cheaper process than curing resin. The base elements are more shelf stable and less toxic too.

    I’d love to find out how they measured the laser power output at different PWM levels on that paper too. Specifically, I’d love to know if our laser output resembles this one at all:

    0_1470719128805_800px-80W_linearity_at_PWM13-40.png

    Because if it does that changes several things about the parameters we would use to calculate optimal cutting power.



  • On a related front, Scorpion just took delivery of a Formlabs Form2 SLA 3D printer. If anyone is interested in having a look, feel free to stop by. The detail on the sample pieces is amazing!

    Brian


  • Design Lab

    Fascinating



  • I have an iBox Nano that I got from KickStarter that I’ve never had any time to play with.
    https://www.kickstarter.com/projects/826799607/ibox-nano-worlds-smallest-least-expensive-3d-print/description

    If I’m not there any sooner, I’ll bring it with me on the 25th and can leave it at the space for anybody who wants to play with it.



  • True to his words, @dhylands left the ibox nano at the space yesterday. I plugged it into power (microusb) and hdmi… It promptly booted up and gave me a linux login prompt. Nothing 3d print specific.

    I hit up the documentation, and it said that the LCD that hardens the resin will give you information… So I rebooted and read that LCD. It was trying to pick up wifi via WPS. So I made up a wpa_supplicant.conf file, put it on a USB stick in place of the wifi adaptor and rebooted. Couple of reboots later I had it connected to makerspace wifi at 192.168.0.102. There’s a webserver on it, so you can access it from your web browser if I get a microusb power supply to drive it.



  • @pierre awesome! thanks for keeping us posted. We should probably create a separate thread for the iBox Nano.


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