One of my favorite things about 3D printing as a hobby is that new capabilities are developing almost daily. It seems like a new type of filament is on the market every day, or someone has assembled a new extruder to do anything from create edible cake decorations to pouring concrete housing. A while ago I ordered [STAR] Alchement's Conductive ABS filament and this week I started testing it out. The significance of this as a printing capability is pretty obvious. If you've also got an interest in electronics, it's possible to simply print some circuitry as opposed to leaving cavities for electronic parts in your prints. My dual extruder printer should be particularly well suited for this -- print regular ABS from one extruder for the main print, and conductive from the other to make "wires" through the print.
Of course, this all depends on whether or not the conductive filament is truly conductive.
The Amazon reviews aren't promising. To date there's one question asked: is the filament truly conductive? One person has answered, and he rather vehemently says no, it's not conductive at all. Likewise, the sole review gave the filament three stars and claims that it's not conductive "by any means."
Well, I've got a roll and I like Alchement's other filaments, so let's give it a try. Here's my disclaimer: I've only run one test so far. I'm going to modify some of the prints to see if I can improve the results. I wouldn't claim that this first bit of data is conclusive.
For a simple conductivity test I printed a little connector, pictured to the right. It's just a rectangle of filament, 40mm long, 2mm sides. The final 10mm at each end is a hollowed out cone, 1mm wide at the very end, narrowing down to .4mm. Hence, a jumper wire or the leg of an LED or resistor pressure fits into the socket and there are 20mm of "solid" filament between the two sockets. (Quotes around "solid" because I printed this at 50% infill. One of the next things I'll toy with is printing the "wire" at 100% infill.)
Quick printing specs: because I'm dealing with a pretty small part and want the sockets to work well I changed my primary layer height to .1mm. The bed is set at 105C and the extruder at 230C. It printed quite nicely at these settings and given how small the part is, it took about 10 minutes.)
Time for some measurements. The picture on the left is the multimeter hooked up directly to the 9V battery. Not surprising, I'm getting just under 8V. (It's a veteran battery.) On the right, I've gone from the battery to my filament connector, then a jumper wire to the multimeter probe. Noticeable drop in voltage, down to 4V, but it IS conductive.
Some immediate thoughts: it's possible that my socket design isn't the best. The wires are all plugged in pretty tight; they won't fall out of the sockets without a good tug. It's worth looking at, though. Also, the aforementioned infill of the wire. In the current configuration (no pun intended) my "wire" is 4 square mm with 50% infill. When printing this as a wire inside another model I plan on making the wire a 1mm cylinder at 90% or 100% infill.
Of course, the multimeter is good for testing but not really a fun application. Here's a little more visual evidence of the difference, using an LED to demonstrate. Again, straight hookup on the left, conductive filament socket in the mix on the right.
Early conclusion: hell yeah, it's conducting electricity! No disappointment here, it's time for more experimentation. :)