jbob

I have taken to doing a material change between prints. I don't actually change the material, but when it reloads the PVA, I let it extrude until i get about six inches without bubbles or debris. it is possible to change the nozzle without forking over 100$ for a new print core. I heat up the print core, remove it from the machine and remove the nozzle quickly. One needs to be ready to work before heating up the core. Make sure you use two wrenches. One wrench goes on the nozzle and the other one on the big square heat block. Make sure you don't allow any torque where the other fitting threads into the top of the hot block. It is very easy to snap off this thin walled connection. It is super thin to keep the heat in the bottom. I've succeeded in clearing a clogged hot end by chucking up the nozzle in my lathe and putting a .6mm drill bit in a drill chuck on the tail stock. I spun it by hand as I felt that would reduce the risk of snapping off the drill bit and allow me to immediately stop if it looked like I was drilling out the brass. Then I flipped the nozzle around and chucked up a drill bit slightly smaller than the end the filament enters. I spun it around with mild pressure on the drill bit until I felt the plastic break free of the nozzle and start spinning. I only did this because I didn't have any spare nozzles. I have a 50% success rate on this because the second time I tried it, I drilled the orifice off the nozzle body... turned a .6mm nozzle into a 6mm nozzle! See below where I describe removing the nozzle from the hot end. There are videos online. Some of the videos try to trick you into buying special jigs/tools, neither of which I own. I've also tried ultrasonic cleaning and dissolving with either hot water, acetone or alcohol. These attempts all failed. When you buy nozzles, make sure they are for the S3 (if that is what you have.) The S2 nozzles are wrong. the correct nozzles are cheap on the south american river web site. I have taken to coating the insides of my nozzles with Molykote G-N assembly paste. It contains molybdenum disulfide which plates out on the brass... Haven't been doing the G-N thing long enough to say if I think it works.