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A better idea would be to use a 3D printer to put down plastic on a copper clad board, then etch it. The accuracy of 3D printers is much higher than they achieved.
Yes, but I want one for other purposes anyway! When I get it (probably after I retire next year) I will try it out.A 3d printer is still really pricey (at least ~$500 if you DIY) and not as fast.
@hevans1944 - my pleasure, I am glad you enjoyed it!
Just wanting one alone is good enough reason They are very cool!! I hope you post some pics when you do get it, let the rest of us live vicariouslyYes, but I want one for other purposes anyway! When I get it (probably after I retire next year) I will try it out.
Bob
I would like to build a 3D printer that fuses successive layers of plastic powder (instead of melting plastic string) with a high-powered pulsed laser diode. Not real sure how to go about laying down an even thicknesses of powder for each layer though... maybe "dump powder and scrape to a uniform thickness" before fusing each layer? Shake off excess powder at the end of the build. Maybe use a piston in an open cylinder, lowering the piston a few micrometers for each layer, pouring in an excess of powder to overfill the newly exposed volume, then scraping the excess off with a blade passing across the open cylinder end. I think something like this one, that is used for metal powder sintering with a 200 watt fiber-optic laser, but using plastic powder and perhaps a 5 watt diode laser to scan and melt the surface.
There are problems with sintering plastic... you need the right kind of plastic. Fortunately progress is being made and a German company has stepped up to address this emerging market.That would be really cool! When I first read the thread I was wondering how you would keep the powder out of your restricted areas, but then when I saw the video, I understood that the laser would be used like a cnc, but to fuse, not cut, the areas desired.
Folks have been trying for years to lay down conductive traces on an insulating substrate... paper, card board, thin and thick plastic, fiberglass, etc. The only "tried and true" method so far, suitable for both prototypes and manufacturing, is either chemical etching or laser ablation of a copper-clad insulating substrate. This provides sturdy high-conductivity interconnections that easily accept solder and mechanically supports components. Laser ablation is not attractive for mass production, nor is any technique that requires "X-Y scanning" of the "circuit board" to produce conductive traces... it's just too slow.
@BGB: Squirting molten metal through an orifice to deposit metal traces on a substrate could work for prototype production, but the engineering challenges are huge. Why bother when there are less expensive and simpler ways to do it? I think the OP (@chopnhack ) just wanted to demonstrate what clever students could accomplish with a minimal cash outlay, re-purposing what many would today consider "junk".
Kudos to them indeed!
Umm... the guy said in the video "we have this big guy over here that's powering all the motors on this giant capacitor just to stabilize everything." And that is not such a ridiculously big capacitor. Might even be a little on the small side if it's less than 10,000 μF or so, depending on current draw. Servo motors start and stop A LOT, creating large surges of current as they do so. The capacitor allows the motor power supply (the "big guy") to play "catch up" in between power surges.Why such a ridiculously BIG Capacitor ???
I think it could be cheaper (and less messy/toxic/corrosive) for "medium-scale" hobby work than buying blanks and doing chemical etching by hand (the PCB blanks seem to be reasonably expensive, as in, several $ per board or so), and not everyone has access to a laser cutter or similar.
likewise, the extruder shouldn't be particularly expensive to make, as it is essentially a modified airbrush pen with a heated reservoir for molten metal (possibly heated with a glow plug). the main hard part is finding a good metal to use with it.
the actual X-Y mechanism would probably be similar to the plotter in the video, with a solenoid valve to turn the air flow on/off, and probably a portable DC car-tire inflater used as an air compressor (or buy an airbrush that comes with a compressor).
(ADD: though for small-scale hobbyist stuff, perfboard is still a reasonably good option. and, note, it would likely require a solid-steel airbrush pen or similar so not to be damaged by exposure to high operating temperatures).
LOL, kids love supercaps I don't know either, maybe that's all he had laying around, we are talking college kids here! (Edit: see more intelligent response above, thanks @hevans1944 )Why such a ridiculously BIG Capacitor ???
I think its an interesting thought, but my first issue with the process would be maintaining a high enough temperature of the "pot" to accommodate heat loss while being blown onto the surface. Convection would take a lot of heat away, so the pickup tube would have to be fairly short or you would have to "super" heat your metal. Either way, I think it makes it less practical - it can be done, mind you - just thinking it would not be practical. I would also consider adhesion issues to the substrate, metal shrinkage, metal wetting/balling when it hits the surface, etc.
LOL, kids love supercaps I don't know either, maybe that's all he had laying around, we are talking college kids here! (Edit: see more intelligent response above, thanks @hevans1944 )
Testing is good....
I suspect it may need to be tested though to see how well it works...
Energy storage capacitors, i.e., capacitors specifically built to store an electrical charge and then discharge very rapidly into a switched load, come in a huge range of voltages, capacitance, and physical sizes. You would be amazed at what you can find stored away in forgotten corners of most college physics laboratories, remains of once-funded research now abandoned.yeah, dunno there...
that is a lot bigger than I have used for anything though.