The item I will look at here, is the new ParCan MK2 hotend. It is normally a 0.5mm nozzle, but I had him make me one with a 0.3mm hole instead.
As some might know, after reading other reviews from me, I like things to be simple. Even when this isn’t the simplest version I have seen, I would still call it just as simple to use.
What is the best way this could function? In a perfect world, the filament would just slide in, and come out in a small steady stream without much force applied to it, and with very low temperatures. But is this even possible? Most likely not, but the designs are still getting better and better. For this so be a good hotend, it should require as little force as possible to press the filament through, and do it reliably over long periods of time. I got multiple other hotends, and I will compare the force needed with those later.
When opening the bag I found two smaller plastic bags inside, one with the hotend itself, and another with the heater block, an extra thermistor, extra power resistor, some wire, and also some crimps to put on the cables.
When taking a closer look at the heater block, I noticed the thread being very rough on one side, most likely the side where the tap exited the material. While it makes no difference to the actual function, it is still something that does not look good, which is a bit sad, because the outside edges of the block are all nicely chamfered and got no sharp edges.
When looking at the barrel and nozzle of the hotend, there are also machining marks, again nothing that will change the way it work, but something that can be avoided. The peek body is not chamfered on the outside, but got a good looking chamfer where the liner goes into it.
For this hotend, there is a bit assembly, but not much. Where I have had other hotends where I had to mount the power resistor and thermistor, this is already put into the heater block, and even done with some paste to maximize heat transfer.
All you have to do, is to screw the heater block onto the nozzle, and you are close to being ready to go. On this picture I still haven’t cut the excess liner off, after doing that it is ready to mount on the printer.
The total length of the hotend is around 56mm from top to tip.
First thing before I started the first print with this hotend, was to test how high I had to set the temperature to get it to extrude properly.
The temperature I found is less than what I use for my other hotends, a lot less actually. With my other hotends, I had to set them to around 270 degrees celcius for abs, to get them to extrude with a reasonable amount of force needed from the extruder. But with this I am down to 250 degrees, so it is a reduction of around 20c, and the layers seems to still melt properly together. I had expected this to be the other way, because with the other hotends, I got the thermistor on by just using kapton, on this hotend it is mounted inside the heater block, so the heat transfer is better and the thermistor will read a higher value, since the temperature from the heater to the themistor is better.
Is this a reliable hotend?
So far, it looks like it. It got a simple design with few things that can go wrong, and the machining work done also looks good and carefully done.
After printing some more with it, I sadly have to take some of the reliability back again. After 20-30 hours of printing, I multiple times have had the PTFE liner to break lose from the clamp holding it down inside the PEEK piece. And also had the first one break its tip off, but it got replaced right away without any questions.
I have looked a bit more into how the PTFE is clamped down, and it is a very sensitive way of doing it. The brass piece is squeezing it in between itself and the PEEK, and if those two pieces are not perfect, and with the right tightness, it will either slip out again, or be cut into and then break.
How long does it take to heat up?
It took around 4 minutes to go from 25 degrees to 250, so that is also a reasonable amount of time.
How hard is it to assemble?
It is very easy to assemble, the power resistor and thermistor is already mounted in the heater block, so all you need to do is to screw it together with the nozzle and connect the wires. So if you got the wires ready, it would take you around 30 minutes to mount it and be ready to print.
Would you recommend this as as beginner nozzle?
Absolutely That depends on what mechanically knowledge you already got. I have had some problems with the PTFE liner, and that might need to be replaced after some time, but the work with messing around with the paste to mount the power resistor and thermistor is already done, so you don’t have to think about that. And even if you break a leg of a thermistor, or you somehow manage to burn out the resistor, there is a spare of each in the package too.
Parts fitting very well together
Easy to assemble
Power resistor and thermistor already mounted with paste in heater block
Well priced when looking that the work and spare parts put into it
Backside of thread sticking out of the heater block
No instructions on why the liner is sticking out of the top
No information in the package about the provided thermistors
The way the PTFE liner is mounted is very sensitive, and got a very little margin for error