I'm new to this game, and recently upgraded the hotend on my Ender 3 Pro to a clone of an E3D V6, as I'm keen to do nylon prints at some point. I noticed however that this one I got has a teflon liner which seems to negate the advantage of a metal hotend entirely.
I'm wondering what temperature it's safe to run this hot end up to?
There are many types of heatbreak clones. In cour case, your clone effectively turns your hotend into an e3d Lite6, not an all-metal e3d v6. To function properly, the PTFE liner needs to butt against the nozzle or you will quickly develop leak and clog issues.
This means, handle it like a Lite6, which has a max of 245 °C listed, but under usual operation should not exceed 230 °C.
It depends how deep it goes. If the teflon goes into the hotend then yes, it will limit the temperature end.
But: the teflon may just be something that ends somewhere in the cold side and sticks out so there is something to put into the extruder or higher up into the connector.
I cam currently setting up a Slice Mosquito for a Bondtech DDX. The Mosquito is full metal, but there is a (actually printed nylon) adapter for the DDS. In this adapter you put a teflon/capricorn tube, that ALSO sticks out only around 5 mm. Here is the point though: it never goes into the even cold side and is only there so the connection to the extruder on top has a width limitation.
So, it really depends how long this tube is (and no-one here will know because a v6 clone may be different internally from the original). I would suggest pulling it out (it should move out easily) and then seeing how deep it goes. As long as it stays on the cold side before the heatbreak, it never gets in touch with anything that is hot.
Long story short, you can print Nylon with a Teflon tube. I've done it. P.S. The nylon absorbs water like nothing you've ever seen. Even after the part is printed, it absorbs water, and expands!
