Here we have the Arcol hot-end, this version is equipped with a 0.35mm nozzle.
The product got quite a few parts, which the image below will show.
It consists of some wooden pieces to build the body of the hot-end, a place to take the pressure of the filament going into the nozzle. PTFE liner to make the filament slide easy through, heating element to provide the heat, heating block the element will go into, heat sink to prevent the heat to rise too high, wires, fire cement, and some connectors.
This is the first time I am putting it together, and it took me a while. Actually around 2 hours to put it together with the wires, and having it all aligned up right. Plus when it was almost done, one of the very tiny legs on the thermistor broke, so I could take all the wires off again and start all over with the thermistor and the firecement to hold it in the heating block.
I had some problems figuring out how to mount the wires correctly, and could not find any good pictures of how to do it, or how it was done, so I ended up almost just letting them go straight up.
But… A few hours after starting, I had a thing looking like a working thing.
The initial test was fine too, it heated up very fast, and the controller could easy hold the temperature close to the desired.
Insulating the hot part from the cold part of it also seems to be pretty good, the copper heat sink is only getting a bit warm, but hardly noticeable.
Next ting I tried was to push some filament through it by hand, and it was also surprisingly easy, but I noticed the plastic leaking out between the PEEK insulator and the aluminium heat blok, so I tried to tighten it a bit more, but had problems getting any tools in there, so I had to take it apart again so I could get a better grip on top of the wooden plate, below the copper heat sink. This operation was a bit tricky, as I didn’t want to move the wires too much, already having broken one leg of a thermistor while initially assembling the hot-end.
Time to put it on the printer!
The big body made it quite a tight fit in the X carraige, and the bolt head sticking out of the top of the hot-end was also quite a tight fit.
But it got bolted on, and looked pretty advanced, but how would it print?
I set the heat to 180c, then pressed print, but with some settings having to be tweaked, it took some attempts before any useable g-code was generated. And after a few more attempts, the g-code started to look right, and the printer running correct.
So now, time to print an actual thing!
But half way through the raft, it suddenly did not look right any longer, like something was bending…. And then the PEEK piece broke, with melted PLA rushing out.
To inspect the problem, I had to take it off the printer again, and take the most of the hotend apart again. And here is what broke, and with it it took the PTFE liner, that got a bend as the PEEK broke.
As you can see, it broke on the top of the thread, around one millimeter over the part with the nozzle in.
So after a short printing experience, I will try to sum up what I noticed.
Is this a reliable hotend?
Sadly no. It looks quite advanced, and got a lot of parts in, but it actually broke before I had a chance to print anything for real with it.
How long does it take to heat up?
I have been running it on 13.4 volts, and with that voltage I heat up with between 6 and 10 degrees Celsius pr. second.
How hard is it to assemble?
Assembly was quite difficult. There was many parts, and they had to be put together in the right order to make them go together, and at the same time there are the wires you have to be careful to not move too much, with the risk of breaking the legs of the thermistor.
Would you recommend this as as beginner nozzle?
No, it is not easy to put together, and does not seem to be robust enough to be able to handle some beginner problems.
The machined parts got a good finish, and almost all edges are smooth.
Parts were fitting together nicely, and did not require much force to make them fit together.
It consist of many parts
Did take some concentration to make sure it was put together correct.
Assembly guide was only clear for some of the steps.
Using the fire cement to keep the thermistor on the heat block was a bit difficult to make look right.
Provided thermistor had very thin legs, thinner than any other I have seen. (and the first broke when I assembled the hot-end)
The body of the hot-end is quite big, and does require some space under the extruder.