Visco Fuse Winding Machine

grabcad

After searching in vain for a usable model of one of these machines online, I decided to give it a go myself. The .stl plates are missing several updated parts; see the STEP or .f3d files for all revisions. The way I have it running now is with one or two strands of KN03 soaked cotton embroidery floss as the carrier core. (The other core option is detailed in the 4.20 update) These run through the funnel, which is filled with very finely milled BP. The first (outer) stage carries 24 cotton threads and the second 8 threads wound in the opposite direction. There is a NC coating stage in the model, but it needs work; not enough dry time and too much tension. I coat it afterwards at the moment. All of the hardware and electronics are labeled in the model (I think; if not it should be fairly obvious what the part is). The gearing is a bit of a mess but it works. The motor runs at 60 RPM. The uptake spool gearing is 3:1 so it runs at 20 RPM. Drive shaft to first plate is 1:4, so inner wrap is 240 RPM. The outer wrapping plate has an idler gear that's a tad larger so it's running a bit slower, probably around 200 RPM. The frame plates are made from 3/32" aluminum. If you want to build this, you're going to have to spend some time tweaking the CAD files to your needs. The f3d file is fully jointed and motion-linked with the correct ratios, so it's fairly straightforward to change gear ratios or even substitute belt drives (which for me gave inconsistent results). It's not quite as simple as you'd imagine to run, but it definitely works and I finally have reliable and repeatable fuses that don't go out and, perhaps more importantly, don't decide to behave like detcord. Much depends on the quality of your BP, as well as the NC coating, but that's beyond the scope of this site. I'm still working on the integrated coating stage and if I get that working properly I'll update the model again.Update 4.20.23 - Added a new hopper. This version spins with the first stage. This helps the core threads scrape the powder off the walls and into the hole. I had to raise the upper plate about 9mm to make room for the new hopper.