So many things wrong with that last statement. First off, lets get the first layer adhesion out of the way... ANY time you work on your hotend, you need to adjust your Z offset because things rarely go back to the exact same. Even just a different torque spec (your hand is not a torque wrench nor is it as consistent as one) changes it. 10 degrees more turn on the thread from harder cranking and now youre higher off the bed. Believe it or not metal does actually flex when you tighten, especially aluminium and soft copper alloys like brass and bronze.
Secondly, the E3D V6 head is shorter than the mark 8. Thus you will need to adjust offset closer, by default, when switching to a V6.
That will fix bed adhesion in most cases. Follow procedure and recalibrate when you make changes and youll be fine. Now, as for temps... raising bed that high is a bandaid setting. We dont use bandaids. Fix the root, stated above, not a symptom of it. This prevents other problems. In this case your bed temp (assuming you're on PLA) is above glass transition. Thats a no-no. Even with proper offset, that causes other issues like the "other" type of elephant's foot. From the bottom layers being fluid and having a taller and more diffuse heat gradient. Basically the bed layer stays put and then layers above it shrink. Till about 5 or 10 layers up. Giving it a bow at the base of the print. You want it hot. But not melted. In regular PLA, thats 55c. 60c is glass transition. You can go to 59c with disgression, but generally you wanna keep 5c away from GT. Be careful with forums and FB posts, people say "do 75c" etc... these are beginners. Be careful taking advice from someone in their first few years of printint. FDM is tricky. It will fool you and teach you bad habits, and you wont realize its hurting you till much later on when you start moving out of the box.
Now all metal temps... who told you +30c? Thats not a thing. If you are having to heat up another 30c to print with all metal, you have a throat clog. Fix your throat cooling system. This can also be from incorrectly installing or assembling it. Same with steel nozzles needing to be hotter. This is a myth. They will equalize just as any other nozzle. The difference is steel has a lower rate of heat absorbtion, and thus takes longer to heat up. It also drops faster than brass as you get into speed printing. Think pouring water on red hot steel. The filament is the water. So * when * printing at very high rates of flow, which most people wont reach anyway, then yes, you run it hotter. But this is true for all hotends and nozzles during speed printing, not just because its steel. Speed printing often has nozzle temps above thermal breakdown of a material because it never has a chance to reach that due to rate of flow and time to heat, but still needs that abnormally high temp so the rapidly flowing filament can grab enough energy to melt in time. Larger bore nozzles also need a small bump because the core of the extrusion is farther from the walls of the nozzle.
But no, V6 and/or all metal hotends absolutely do not need extra temps under normal use (like 0.2 layers at 60mm/s). The run at the same temps. And so does the bed. If it still doesn't stick and you know for sure your z offset is good, and you preheated and all the stuff youre supposed to do when setting that offset, then your bed is dirty, wipe with alcohol. Or the coating is worn out. Or, on bare glass and large base prints, you need an adhesive like 3D Lac or gluestick (not regular white, or gel, you need Xtreme or extra strength, or purple). If you have to heat up the hotend to extrude on an all metal or nozzle change, figure out why youre having throat clogs, because thats not a normal thing for a well-functioning hotend and extruder. That indicates a problem somewhere. Either user error or poor throat cooling. It can even happen with really cheap and poorly made nozzles. V6 does not mean its genuine E3D. If you see V6 and its not directly from E3D or a company in a contract with them, then its a Chineese clone. Yes, it matters... Their geometry inside the hotend needs to be machined properly, not rushed out cheaply. Thats why genuine ones cost more, and its how they got their reputation for being amazing hotends. They take care with machining, and they test and refine stuff, in house, daily.
-The guy that started on a Cupcake back in 2008-2009 and now teaches it.
