Solved Underextrusion?

I put this in after the G28 homing command:

M565 ; X0 Y0 Z-1

Is that at all what you meant?

 

Thanks. Still have the weirdness, though. I've been trying to up the extrusion multiplier and temperature in hopes of getting the layers to be fatter and softer and more prone to adhering when something occurred to me. Look at this picture of what's supposed to be a cube:

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This is most definitely not a cube. I do remember that the guy I bought it from said that they'd upgraded the lead screws to the "faster ones." I still have the old lead screws , and I can see that they are much more finely threaded.

Is there a chance that the firmware hasn't been told that the screws are moving the z axis much more radically for what it thinks they're being moved? Instead of making a cube, it's stretching in upwards, laying the plastic down slightly higher than it ought to with each pass? I have printed many of these cubes, and despite all of my tweaks, I have never gotten anything close to a smooth side of one. It's always this coarse "wicker" look.

Does anyone think this makes sense? And if so, how would I go about fixing it?

 

Coarse lead screw installed; what I think is the finer, original lead screw lying on the bed in the foreground.

 

I didn't put these lead screws on; they came that way. How can I tell if I have the right firmware?

 

Great! That explains why I was getting a rectangular profile instead of a square! I'm getting there. Thank you!

I've been under the hood just like I knew I would with a special-needs printer, and I appreciate all of the help. I'm much closer than my first try, but still wondering what's wrong. The sample below is my latest test cube. As you can see, the top still won't fill in, even though I have it set to print four layers on top and bottom. The sides are hanging together a little better, though they're tipp very striated and can be pulled apart with less force than I'd like.
Considering I'm only able to print with the cooling fan disabled, do you think my next step is to try to replace the heating element in the hot end? It just seems like the plastic is too cool in general to weld to itself. Or is there some other setting I can adjust?

And boy, am I looking forward to allowing myself to print something besides a #2%&$$ cube.

 

OK. I'll do that and get back. Thanks so much for all the advice!

 

Yes - process of elimination. A new heater will rule out "too cool." I just wish I could print something that I couldn't blow air through. Thanks for the help.

 

OK - back from a vacation and a three-day power outage. The new heaters arrived and I installed one. It kept the temperature right at 200 for the whole print - even when I allowed the fan to kick on, which was something I couldn't do before without a "Temp Fall" error.

So that's the good news. The bad news is that my prints look the same. I tried a couple since, but they look so much like the picture above, I don't see the need to upload a new one. I even tried one with an extrusion multiplier of 1.5, which was maybe a tiny bit better. The glaring problem is the completely open top, despite my setting it for 4 solid layers on both the top and the bottom. Bottom isn't really much better. Maybe slightly, since it's melted together a little more. There are a lot of blobs along the side, yet also big spaces where I can slide my fingernail into the print.

Does anyone have a suggestion for what to try next? I'm sorry to drag this on for so long. I could start a new thread if need be. I appreciate everyone's input. I'm really stumped.

 

Yes - still the blobs. It's been set for 200, though I guess the thermistor might be supplying a faulty reading. I've taken the nozzle off and used a propane torch to burn it out, though I was chicken to do it for very long. Should I disassemble it more? Or can I just replace parts of it to be sure?

 

Yes, it can extrude - even down to 180, though I sort of have to push it to get it through. I'm starting to wonder if the feed mechanism is wonky. I made some marks on the filament so I could tell whether it was moving consistently. I also rigged up a spool holder behind the machine that spins as freely as possible. I don't see any roughness on the filament if I pull it out, so I don't know if the teeth on the extruder are slipping or what. Here's a video of the erratic feed...

https://drive.google.com/open?id=0B0h8tuF7pBGyMHNWbnh5YTBBOTg

 

I will take it apart and have a look today.