I have my Taz5 for almost two years now and even before I got it, I was concerned of a couple of things. First, the fact that the material was exposed out in the dust and everything else in the room while printing and second, the humidity and everything related to it. I must say I like my Taz and one thing I really like is the building volume.
So I knew I had to find a way to keep my filament protected at all times during short and long prints and, if possible, dry. And when I was introduced to nylon filaments I knew I had to find a way to keep them dry for sure. And then there were the filled filaments that, according to manufacturers, due to their brittle nature when cold, should be fed through a heated path.
And, almost two years later, I can finally say that I have an almost finished project that I can share with anyone interested at. I have to say though that it may seem simple but it’s actually a bit complex because it involves some knowledge of DIY electronics and PCB making, unless someone can help you with this.
So, here are some pictures:
The box and the hinges are made of nGen. I have tried ABS, HIPS and PLA but they would suffer either from warping, delamination or the temperature. nGen printed out without a hiccup and with a Tg of 85C works just fine for me.
The hatch on the side, right beneath the PTFE feeder, is required for accessing and feeding the filament in the tube and for providing the blower fan. It is designed to print with the entire box, serving as a support as well, and just snaps off at the end.
The gray slots that hold the hot wire are made of nGen Flex due to its flexibility and extreme Tg of almost 120C.
The bolt that holds the spool is M6 and not M8 for a very simple reason: I couldn’t find a way to make a 3D printed retainer strong enough to use with a 608 ball bearing and still fit a Taulman small spool (1lb). And I love these nylons! So, M6 it was using the 626 ball bearings.
The hot wire that I use comes from McMasters and it is the flexible 8ft-24V/1A one. For the box I use two (2) of these and one for the PTFE tube. As you can see from the pictures, I just twisted the wire around the PTFE tube and used a clear tape to keep it in place and insulate it just a bit from the environment.
The blower fan help to circulate the hot air inside the box, improve the drying process and protects the box from overheating the walls. Early designs didn’t have the blower and the box, running on 48W (2x24W hotwires), was getting really hot on top (heat goes up, right?) affecting its shape! Now the temp goes up to 65-70C and works great. Running 24W on the PTFE tube rises the temp up to about 65C.
The thermostat circuitry is designed to use a 10k thermistor for control (T and ΔT) and a KSD9700 bimetal thermostat for overheat protection.
This post is getting really big, so I stop here. I only want to say that this design has worked great for me and I just can’t think of any other way to work with Nylons and PCs.
Should anyone feel that would like to give it a try, just let me know and I will post the STLs, the BOM and instructions.