Unresolved Can't seem to get a decent print on one printer

JoshYourITGuy · Aug 17, 2015

I own 2 R1's, one is a bit older (end of 2014, has panel on bottom, but has X limit switch on extruder assembly) and the other is a bit newer (early 2015, X limit switch on X carriage instead of extruder)

The older R1 was precise but not accurate, I resolved that issue with a few tweaks including the following:

Updated firmware (fixed Z steps-big help, enabled Z motors, enabled Z baby-stepping)

Calibrated E-steps using the 150mm mark, extrude 100mm, do math method

Tightened every nut, bolt, belt, cable on the thing

Added the ball bearings to the couplers (huge help)

I am now precise and accurate on the older machine. I have had my share of issues with this older machine (bad limit switch, failed linear bearings, clogged hotend today, and cracked parts) but it is still highly precise and accurate with nice smooth prints.

The newer machine is a different story and it is beginning to bug me.
I performed the same tweaks as above, but I am having issues.
My prints come out with a slight gap here and there, which leads to cracking in the future.
Here is an example:

I have done the following:

Verified extrusion rate again (this machine is slightly higher than the older machine)

Verified filament diameter (1.72 to 1.76 - I have been happy with HatchBox)

Tried slowing things down a bit (Love the XXL Controller)

Played around with the extruder tensioner both super tight and super loose.

Completely disassembled and cleaned the extruder assembly including verifying the hobbed bolt was in fact grabbing the filament dead center. There seems to be a bit of filament grinding going on, but I can't tell what's causing it.

Verified the nozzle was 0.4mm

Here is a shot during the initial layer, it almost seems to skip here and there:

And one more a few layers up:

Here is a shot of the grinding I mentioned:

I just don't understand what the issue is or how to resolve it.
Any help would be appreciated, it is bumming me out because the older one is for work and the newer one was purchased for home, so now I have a wife who is not happy because we saved up for this and she can't use it yet.

Thank you.