What term do I look for to find compatible nozzles?

I think it is time to replace the nozzle on my printer, but I see terms like MK6, MK7, MK8 when searching for replacements, sometimes with thread sizes as well. The manual for my printer only lists the extrusion size (standard 0.4mm), but does not list the thread size or length, which seems like it will be needed to make sure a replacement is compatible.
I think that a nozzle labeled as MK10 or MK11 should be appropriate for an i3 Plus style printer, but I dislike picking blindly without understanding what those terms actually mean. Can someone explain what I should look for.

And is the PTFE tubing typically replaced when the nozzle is worn, or does that item not wear with use?

thanks
Chris C

“MK” means “Mark”. It is a little like a version of a system. So MK10 is the 10th version of the heating system of those printers. Some versions are compatible with previous ones, some are not. MK10 is not compatible with previous version, MK11 is compatible with MK10.

Regarding the PTFE tube, it is a consumable. It should be changed from time to time. This frequency is not directly related to the nozzle. It is mainly dependent of the temperature you are using. Personally, I have upgraded the heating elements to one that do not need a PTFE tube (micro swiss).

I am familiar with that use of “mk” but my (maybe incorrect) assumption was that there would not be many variations in a particular model. I thought maybe mk 1 was the original RepRap design, maybe mk 5 was one of the mini variants, mk something was a high temperature variant, etc.

How many of the (at least) 11 variants have actually been used in i3 Plus based printers? How do I find which is installed in my printer? I looked at the hot end, but I don’t see any identifying markings, at least none that I can see through the filament residue, it just looks like the pictures of every other stock heating block and nozzle that I have seen.
If I remove the existing nozzle and measure the thread diameter and pitch, and length of threaded section, is there a table somewhere which cross-references the differences between the different generations?

I found what appears to be the Wanhao spare part store on AliExpress, which has hot end parts labeled as “MK10” for the Wanhao i3 series, and 2mmx4mm PTFE tubes. Does that imply that all stock printers from Wanhao (and derivatives, my printer is actually a Monoprice re-branded that I purchased from someone else) have that same hotend, or will I have to disassemble to make sure?

The Wanhao i3 Series are only using MK10. MK… are for all printers.

Thank you, just what I needed to know.
I may add BLTouch later, I will consider the MicroSwiss hot end you are using as an upgrade then.

Chiming in to say that the MicroSwiss hot end is a really nice upgrade, but it takes some experimenting to get the settings (temp/retraction) dialed in. If you primarily print PLA, it’s probably more trouble than it’s worth, but an all metal hot end is essential if you plan on printing higher temp materials and the one from MicroSwiss is really high quality.

Is my intuition correct that the 240 degree limit of the extruder (according to the manual) is because of the breakdown temperature of the PTFE tube? What temperature can an all metal extruder realistically achieve? Can you print with the fiber reinforced nylon filaments that recommend 260 or 270 degrees using the all metal hot end with one of these printers?

Yes, those temperature limits are because of the PTFE tube as PTFE breaks down and emits toxic fumes when heated past certain temperatures. Personally, I wouldn’t heat a PTFE hot end past 230 C. Also, there are going to be firmware limitations, along with other hardware limitations (power delivery, thermistor temp ranges, etc.) that will keep the practical max temp below 300 C. I forget what the max temperature in the ADVi3++ firmware is by default (maybe 285 C), but it’s high enough to print nylon at 260 C which I’ve done several times with good results. I haven’t tried any higher temps than that.

It is 300 C

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