Continued issues, but narrowing it down with Josh's help at MG. It would be nice if it were working now, but I have to say it has become an interesting hunt. Erroneous temperature readings are a prime suspect. When it is resolved I'll post the results here for reference.
FYI, off-topic about the nozzle and threaded tube...when I cleaned them out, I found remnants of old filament in there that I thought had been flushed out ages ago. I don't know if that hurts the quality of the prints, but I'm sure it doesn't make them any better. Now I'm thinking of having separate extrusion paths, maybe even the whole hot end for convenience, for different filament types. Might be overkill, but I'm considering it just on principle.
Problems Printing Colored PET+
Re: Problems Printing Colored PET+
Dave, that old filament you pulled out just hardens in the barrel and nozzle after a while making new plastic harder to extrude. Just after i made that post about this the other day, i changed filaments again and i could tell it was getting tight. I got the clicking here and there. I pulled it apart and soaked it in my spray gun stipper bucket. There was a piece i pulled out of the tube that i should have taken a picture of and posted it. It slid out of the tube real nice and if you looked at the end of it you could see all the rainbow layering of each color plastic that went through the hot end. It was like seeing a cross section of 15 different color paintjobs. It was really the first hard proof of this build up of different plastics.
Re: Problems Printing Colored PET+
Interesting! Is the stripper you soak it in thick or thin? I bought some stripper at Home Depot the other night, with methylene chloride and other nasty stuff mixed in. It was quite thick and I'm not sure how much it actually got into the tube or nozzle (which I couldn't get apart). I ended up cranking off the old tube with vice grips and replacing it with a spare new tube, then threw it away. I should have taken a look inside.
Re: Problems Printing Colored PET+
the stuff i use isnt. its watery in a 5gal pail with a stainless soaking basket. i tell everyone to get the stuff at home depot because i dont know where the average person can go locally to buy methylene chloride. its not exactly available on every street corner. you will really need to get the nozzle off the tube. use 2 m6 nuts and lock them together on the tube so you can take your nozzle off. you dont need to kill it either when you put the stuff back together. just try to work the stripper down in to the tube. i know its pretty thick. its like that to keep the meth on the paint your trying to strip so it can work and not just evaporate away. i was in HD tonight and i did see they had a sprayable version thats watery. that might work better but im not sure whats in it. it didnt say on the can but its not tree hugger stuff so its prob meth chloride.
Re: Problems Printing Colored PET+
Just following up. I was sent a new thermistor. My old one was giving erratic readings when the wire at the thermistor was moved around. I also ordered a hot end as a spare. Anyway, rather than replace the thermistor and see how that worked, which would have been the proper way to do it, I used the new hot end and left the original hot end and new thermistor as a project.
In short, it worked. I still saw some short lengths of filament that inexplicably lifted after being laid down, but the lengths were a few millimeters for the most part. Those little bits stuck around the tip of the nozzle, but didn't seem to have adverse effects, and the next layer to go down "fixed" the short bit of missing filament. I've heard that some build up at the tip of the nozzle is common for that filament, so maybe that's what happens to cause it.
So, I am happy again, thanks to Josh's attention to this. Even though I replaced the whole hot end, I'm sure it was the intermittent thermistor connection problem that was the root cause. When I have some time, I'm going to put the new thermistor into the old hot end, clean out the PET+ in it, and use that for non-PET+ prints.
I can't say enough good things about MG!
In short, it worked. I still saw some short lengths of filament that inexplicably lifted after being laid down, but the lengths were a few millimeters for the most part. Those little bits stuck around the tip of the nozzle, but didn't seem to have adverse effects, and the next layer to go down "fixed" the short bit of missing filament. I've heard that some build up at the tip of the nozzle is common for that filament, so maybe that's what happens to cause it.
So, I am happy again, thanks to Josh's attention to this. Even though I replaced the whole hot end, I'm sure it was the intermittent thermistor connection problem that was the root cause. When I have some time, I'm going to put the new thermistor into the old hot end, clean out the PET+ in it, and use that for non-PET+ prints.
I can't say enough good things about MG!
Re: Problems Printing Colored PET+
I just used Jim's file on black and it was one of my best prints yet. thanks Jim