Compatability issues using a Mk8 style heatbreak with V6 hotend.
I have a V6 heaterblock on a mk8 style heatbreak and extruder assembly. This arrangement is working but I'm having a bit of a problem with underextrusion when printing too quickly. I start encountering problems with 0.3mm layer heights, 0.4 width and around 50-60 mm/s print speeds with 1.75mm PLA. I have even had to raise temperatures by about 20 degrees celcius to try to counter this problem.
The mk8 heatbreak in question is 40mm long and has an external m6 thread and an internal PTFE tube lining on the entirety of its length. The PTFE lining goes all the way up to the nozzle inside the heaterblock.
It seems to me that the PTFE tube is insulating the top part of the heaterblock and drastically reducing the meltzone in the hotend, hence leading to the underextrusion I'm experiencing.
The short side of the V6 heatbreak which sits in the hotend has no lining so I would expect that to act as part of the meltzone and just wanted to confirm that is the case.
Is this a good question?