As I mentioned in a previous post, I purchased an Arcol.hu hot end. This week, I started assembling it. Lazlo’s got some good instructions up on his website, so I was able to follow those and assemble the hot-end without any dramas at all.
The biggest hassle with assembling the hot-end is trying to protect the thermistor. It’s quite fragile, and the arms can break quite easily. So naturally enough, you start off by wiring up the thermistor. The very thin connecting wires were quite fiddly to try and strip as well.
After that, you need to connect up the power resistor in a similar way.
Next up is to fit the power resistor into the heating block. It’s quite interesting to see that most of the hot part of the hot-end is made of aluminium. I haven’t chatted with Laslo, but I suspect that it’s because the thermal gradient on aluminium is extremely steep. Away from the active heating area, it will cool down extremely quickly. I suspect that this is why Arcol design has such a short hot zone.
This also makes it easy to fit the power resistor, as you can then safely use aluminium foil as a wrap around the power resistor to ensure a tight fit.
At this point, the instructions on the website diverge slightly from the current hot-end. The instructions on the website are for version 3.0 of the hot-end, but the version he’s currently selling is version 3.01. There are only small differences, mostly down to an improved heat-sink. It’s pretty easy to guess the correct way to put the remaining pieces together.
In all, quite a fun and interesting build. My only gripe is that the PEEK block doesn’t sit totally flush with the lower mounting assembly. This results in a very slight angle to the nozzle. You can see this in the photo below. I can’t really see how this could be a problem for printing though. The millimetre or two of offset isn’t going to cause any problems, as long as it’s consistent.