Hey everyone, brand new coil builder here. I’ve done 2 coils out of pre made Kanthal fused Clapton wire and a screwdriver. The first one opened up to larger than I wound it. I read about heating the wire beforehand to take some spring out of it, and the second coil was much better. Do people use a smaller mandrel than the finished ID to compensate?(say 2.5mm to make a 3mm ID?) Or do I need to do a better job preheating the wire?