Hi aardvark, no problem.

You get sheets of buildtak with it, but I don't use them. Far too finnicky to get right and always tearing them apart when prying loose parts.

I found that a sheet of ULTEM PEI (the plain amber stuff) works perfectly. Stick it to the build plate with high-temp double sided adhesive, and roughen up the surface with some fine steel wool. Then it a matter of getting the z-zero right. Too far and the part will warp, too close and it takes a lot of effort to tear the part loose. However, the PEI sheet can take an enormous amount of abuse (I have a 3mm thick PEI sheet stuck directly to the 8mm alu build plate), so try pretty close and gradually increase the Z-zero to get them tight, but easier to remove.

Print at 250-260 C with 30-40 mm/s. Take into account about 0.2-0.4 % shrinkage when slicing. Heatbed starts at 100 C for first layer, then 99 C for layer 3 and 98 C for layer 5+ (S3D settings)

Parts are very strong and can withstand higher temperatures than ABS.

I do have a heated chamber. I put a compact electric heating element+fan inside the enclosed printer, and control the temp with a cheap chinese temp controller (10 euro). The fan I put on the mains permanently, so that it keeps running when the heating element is off. Otherwise the fan will turn on/off with the heating element and the latter will dissipate more heat to the fan when off. The temp controller regulates the temp inside the printer, the fan moves the air around to

I also have a micro-swiss full metal MK10 style hotend in my replicator clone for polycarbonate (and PEI). Works very well, have two more in the mail now.