Hi Jason, I wish that the fix was that easy.
I happen to have a two stage, oil sealed, 50 liter/minute scientific vacuum pump. The vacuum reached is below 1/10,000 of an atmosphere which is much better than heating to eliminate moisture, plus low vapor pressure organic compounds, and air that has dissolved or diffused into the filament etc.
I don’t have a scale sensitive enough to weight the spool before and after drying to measure how much water was removed. The best indicator I have is using x10 optical magnification and inspecting the purge line of clear unblended hobby king polycarbonate printed at 290C. I don’t get any bubbles in the first 16 hours after vacuum drying, the next day I can see a few small bubbles in the purge line. Vacuum dried Nylon has no bubbles as long as I don’t exceed the maximum extrusion temperature. It is interesting how quickly above the maximum extrusion temperature the Nylon chemically breaks down and forms bubbles.
In the new cetus extruder, I think the Nylon melting point position between the cold and hot end just happens at a bad point and the Nylon sticks to something. I would do more experiments but I don’t think the white tube liner in my cold end will survive any more Nylon printing tests.
To be clear, I can heat and extrude Nylon at just over 260C and it still has no bubbles, but in the time it takes to move the nozzle and start printing the purge line it jams. Extruding at 270C it has no jams but you get a print full of bubbles with no strength so not a very useful print.
It would be good to know the maximum service temperature of the white liner material to be able to melt out filament jams!!!
Lastly it is possible that by simply changing the air flow over the cold end you could move the melt position up or down just enough to fix the Nylon sticking problem.