I've been having trouble keeping my heater barrel at a constant temperature. It tends to vary about 10 degrees while it is hot. This is just what the thermistor is reading, I assume it's actually varying more. i found that I had to keep it above 250C to get ABS to consistently melt. So i decided to make the barrel even closer yet to the Makerbot MK4; I had to get some ceramic tape. Unfortunately I also wanted more nichrome wire, the Makerbot shop was out... crap. Fortunately there are a lot more people selling reprap vitamins on the internet now. From Ultimachine I ordered about 60cm of Ceramic tape and 5' of nichrome wire and they also sent some amount of plastic filament in green and brown. Thanks guys.
I was just going to warm the barrel and see how it's pushing plastic now but it quit working and started cooling after it hit 140 degrees Celcius. Crap. This is the second time this happened, I have to assume it's either the nichrome wire the I got originally from Profound devices or something in the way I am wrapping the nichrome around the barrel that's causing such a consistent failure. I'll have to dismantle the heater tonight and see what's what.