Press failing to extrude

I commented in the other thread about jamming/extruder issues and want to add some of my own testing as well. Not sure if there's a preferred place to discuss this.

I noticed the fan on the extruder seems...oddly placed. I don't yet understand why nearly half, if not more, of the fan's area is facing a flat non-porus surface (the motor body) with no outlet. I also think that my fan was pulling air through the heatsink as opposed to pushing. I went ahead and flipped that around, don't expect that to do anything but it's on record.

I also finished a little 3D-ghost-pacman while my other machine was doing the same, to compare. It's the longest print I've done so far on the Press and went off without any issues. On top of that, it printed from a very warm chamber since it had been idling for awhile. I made no changes outside the fan flip, but this is a single data point and all things tell me the fan change shouldn't do anything. I think it's worth noting that I had opened the lid 3 times during the print to peek inside.

I made a slight attempt at changing the tension in the idler but can't get it to cooperate. (If anyone else dares this, I'd recommend lacing something through the spring while you try to tighten or unwind it, so if it gets away it can't go too far).

I'm very curious about the results from a change of filament, can't wait to hear.

(Currently still using SoliPrint)

Had a jam, and needed to clean things out and rethread the filament. Had a second jam immediately. Combination of knocking and grinding. Was greated by the following (photos) when taking things apart again. 

Everything had been sufficiently warm for awhile. What's interesting to me is that in cleaning out the hobbing I had to remove the most readily accessible metal portion of the extruder and found it easy to handle. Was certainly warm but neither it nor the hobbed hub were excessively warm. The hot end was readily hot.

Three photos for evidence (album link if the attachments don't work )

imgur.com/a/utuG1

1.) Shows the filament I removed, ground out portion of filament, and a curious shifting of the filament at the point of entering the hot end at it's attachment point.

2.) A rough doodle of mine with the filament overlayed.

3.) Filament and doodle separate (started to label but figured it was understood enough).

I'm now very curious about the following things:

Placement of the hobbed hub. This thing sits very far inward on the "shaft" made by the inlet to the cold end and inlet to the hot end. The filament has to make quite the turn to actually get around it.

The connection between the hot end and cold end. I'm wondering if the hot end isn't properly dumping heat to the rest of the extruder.

I think I'm going to see if I have any thermal paste good enough for 250C and apply it to the connection between the hot end and cold end. As far as the position of the hobbed bolt...it really bother's me and I really wish I had an easy fix for that. It'd either mean shifting the entire metal construction over a little, or making a smaller diameter hobbed hub.

EDIT: Forget that thing about the paste, nothing I have is that temperature.

Update 2+:

One more thing- I removed that clear plastic vanity cover over the housing. It seemed to impede airflow across the spur gear and it also allowed for a build up of plastic dust next to the gear itself which only seemed to exacerbate the slipping/grinding problem. I'll give it to Solidoodle; it looked nice but I don't think it works all that well functionally.

nice.  are you using soliprint?

Yes, I'm using SoliPrint. Going on 6 hours now with continuous use and no problems/jams.

And yes, I reversed the fan, removed the vanity cover and used the higher quality filament.

Last night, I tried printing with the SainSmart in the original roll it came in. Because the roll didn't fit the cavity in the top of the Press perfectly like the stock reel does, a snarl eventually developed. The extruder head got caught up while the belts rotated so the head was shifted over a couple millimeters once the snarl cleared. A failed print, but I don't chalk that one up to printer error. That was me trying to use the printer in a way that was not intended. But the good news on all this: even after the filament got caught with the drive spur essentially grinding away in one spot for a bit, extrusion resumed (albeit off center) once the snarl was removed.

So for this print today, I respooled the SainSmart on the stock Press reel and everything is flying. I highly recommend doing this. I was worried that some snarl would develop because I wouldn't be able to get the wrapping as even as it was done on the SainSmart and Solidoodle reels to begin with but my uneven respooling efforts don't seem to be making a whole lot of difference at all. A word of advice on the respooling: the ABS is spooled at first when it's probably warm from being created in the first place so it retains the circular shape of the original reel it was placed on. If you respool any filament, but in my case the SainSmart filament, from the outside strand working towards the inner end, you basically reverse the filament on the new spool. Meaning that the largest circles of filament will be on the inside of the new reel while the inside filament will be on the outside of the new reel. Basically, this causes the filament to jump off the new reel easier than it should because by respooling the filament in that manner, you are forcing filament used to bending in a much tighter radius to bend in a much larger radius. So long story short, try to start respooling from the inner end and work outward. You'll have to remove one side of the SainSmart reel to do that. I know that's confusing. I can't think of a better way to describe it. Just try it for yourself and you'll see pretty quickly. That being said, printing with both tops closed seems to make all the difference in keeping the filament on the reel before it's pulled off by the extruder.

I think Solidoodle designed a really great extruder, it just happened to come with some massively crap filament that couldn't handle it.

Print is almost done. I'll post pictures if the forum lets me.

One other thing to add, I was having major filament shredding issues.  It didn't matter what filament brand I would use, case open or closed.... My prints would always fail during or just after layer 1.  The extruder wheel was grinding into the filament.

There are multiple causes for this.

The end result for me was actually my z offset calibration.  Layer 1 would always print as a bunch of smears, instead of the bold lines you would expect to see.  Since the head was too close to the bed, the first layer was too hard to push out.  The filament jammed.

To fix, I sent codes m502 and m500 to reset my printer to factory, then reran the z offset wizard in soliprint.  I hit the checkbox in the wizard for the correctly printed line, and bingo; big fat lines on layer 1 and no more smearing.
My press printed all night without trouble.