We’re back in business!

The last time I had tried to print something, I noticed a bunch of smoke coming out of “C” in the diagram below.  And things were dripping too freely.  I had the thermister at position “A” below, just how its supposed to be.

Thanks to acquiring a digital thermometer capable of measuring temperatures up to 200C, I was able to read my own temperatures – and sure enough – Fred in this chart.  The real temperature in the barrel was much higher than was being read.  Why?  This makes no sense!

Well, luckily I had watched a video on how to put a print head back together, and it turns out that I had not looped some Kapton tape around the nozzle first, I had put the thermister directly on there, and then covered it up with tape.      I tried it the other way:  One loop around with tape, then the thermister, and then another layer of tape, yielding sample Barney.   (I also put the fiberglass insulation (tattered, but still in one piece) on it like they suggested.

Much better!   We’re in business.. almost.   While printing, the tape gave way and the thermister fell off. 

Why, I wonder?   My guess is that by having one loop of kapton tape, and kapton tape is a good heat transfer agent, it gets to sample the average heat from all around the nozzle, all around the thermister, rather than just one side of the thermister.  Or something like that.   Or maybe there’s just a bad spot on nozzle and I was unlucky.

I tried taping it back on 2 more times.  No luck.  I seem to have done something to the print head, the wires are shorter now, and after much cursing and screaming, I gave up.

Instead, I put the thermister in at location “B” – inside the fiberglass insulation, which held it snugly in place – and yielded sample Scooby.   We still seemed to be in business.   And here it is, printing:

The URL to the above camera is https://www.dropcam.com/p/sunnywiz, although there is no guarantee that it will be pointed at a geeky subject at the time this post posts.

(Those things in the picture, btw, are thingamabobs (technical term) that Jason needs in his Arcade machine build)

Yay! so now that its back to working again, what now?  Hmmm..

For future time historians, the list of all posts on the clog:   http://geekygulati.com/tag/3d-printing+clog/

Jason did a great job on the nozzle, but after I had it up and printing (nicely), i noticed a trail of smoke coming from the PEEK barrel.  (Why the heck is it named that?)

I think I have the barrel too far up into the PEEK thingy, and the heat is heading up there and melting things.

Also, with the thermister dialed in for 140, the plastic was dripping freely … i suspect that things are MUCH hotter than they are registering at the moment.

I might need a secondary source to determine real temperature.  I wonder if my IR gun can get close enough for an accurate reading.

@jstill is the Man.

Here’s what he did to unclog the nozzle.

1. Put it on the Grill, for a while, at 700 degrees or more.     At the end of this, it still had black stuff all over it.  (Much better than my idea of the oven.. no wife being annoyed at me for stinking up the house)
2. Tried to remove the black stuff with ____ (I didn’t quite catch it) and Mineral Spirits.. didn’t work.
3. Had a Eureka moment, realized it was all carbon, so he used Hoppe’s No. 9. Gun Bore Cleaning Solvent. A single wipe, and it all came off.
4. ‘Tis beautiful.

I think for good measure, I’m going to pick up some guitar strings and run floss it as well.   Then put it on and test.    This time, definitely tighter on the barrel .. I think it was loose, when I removed it, there was filament where filament ought not be.

Excited. 

Well, we tried.  And its better.  But it ain’t fixed.

Here’s the first bits of print that came out of it.  You can see the dark stuff that was either the old filament or burnt:

However, the stream of filament coming out the end keeps varying.  Sometimes its good, and then other times it fizzles out:

Conclusion: There’s something still clogging the bottom thing.    More work needs to be done.