Layers collapsing onto each other after E3Dv6 upgrade (Page 2 of 2)

That actually is beginning to look good. I would go up another 5 degrees as it still looks a bit cold.. Did you confirm your set temp is actual temp on hot end? Notice the layers are much more parallel and directly over each other on that print where as all your others the layer kind of just where all over the place in the vertical axis. I would consider this usable, but could be better.

I'm actually running a DRV8825 driver in 1/32 microstep mode *and* a Hobb-Goblin.

Sadly, now the HG seems to be trying to eat through the filament - every now and then the filament seems to stop feeding and I find that the filament has been nearly eaten through by the hob. It extrudes fine for a while, then all of a sudden it'll just stop...

I'm suspicious that there might be a slow clog in the nozzle that I need to clear. Maybe the heatgun-and heat-resistant-desktop method or an acetone soak... I've got a spare nozzle if I need it. I've tried wire but whatever the blockage is, it just comes back.

I'm also a little suspicious that the tension on the hob might be too high, but I can't set it any lower - the screw just isn't long enough.

Not sure if I mentioned, but I'm using mdroman's E3Dv6 mount (based on Lawsy's mount): http://www.thingiverse.com/thing:431363/#comments

I'm running at 235C at the moment. Yes, I've changed the thermistor type.

0.40mm E3D brass nozzle. The filament is some that I got locally, no brand. Black ABS, 1.75mm, the only branding on it is... a small label in Chinese.

I'm pretty sure the replacement nozzle's clogged now - I got another print out (one of the parts for Lawsy's carriage) and started the second, then it stopped feeding and started chewing filament again. Retracted the filament, cut off about six inches after the chew and re-fed. Now instead of the easy-feeding straight lines of molten plastic, I'm getting curls of molten plastic which twist and tangle as soon as they exit the tip of the nozzle and end up sticking to the heatblock.

What gets me is, this filament worked great until I got to about half way through the roll (where I'm at now). Now it's just problem after problem.

EDIT -- This is the filament I'm using: http://www.ebay.co.uk/itm/351015776147

Wow, that worked well! Took it up to 280 and hit extrude and the nozzle cleared right up!

Which begs the question, why is it clogging at lower temperatures?
I might try it at 250 or so and see if that cheers it up a bit.

Thanks,
Phil.

Could be that you used a higher temp material like ABS and then went to a lower temp material like PLA without liading the lower temp at the higher temp. When going from a high temp to a low temp you need to load the lower temp at the higher temp then several hundred mm at the higher temp to purge all the high temp material. Otherwise you could have small bits of the high temp left in the extrusion path that won't melt fully or at all at the lower temp and cause clogs. This is one reason I like dual extruder systemd. I use one extruder only for low temps and the other only for high temps.

Just checked the temperature with a thermocouple and repeated the PID tuning.

I started out with:
echo:   M301 P37.55 I4.15 D84.89

New PIDs are:
ok p:33.92 i:5.45 d:52.79 c:1.00

With a setting of 250C, I'm getting 235C at the hottest point on the heater block. So it's probably fair to say my temps are a bit low, and the extruder kept jamming.

I had to increase the temperature in Pronterface to 280C (262C measured) before the filament stopped jamming. Does this seem too high for ABS?

Most ABS should extrude just fine at 215°-230°C. 

I've tried probably 20-25 different brands of ABS (I don't use PLA), and the only brand of ABS I ever came up on that needed 250°C was from Affinia.  That particular stuff is made specifically for the Affinia printers which extrude somewhere between 250°-260°C.

What brand of filament are you using?

I have an all metal hot end (E3D clone), and I run ABS at about 220°C  Depending on the roll and brand, I've gone as low as 215° and as high as 225°.  The only thing that wouldn't extrude at those temps and required me to kick it up to 250°C+ was the Affinia branded filament.

With the original hot end setup (MG Plus with the thermistor taped outside), I used to run ABS at 195°, then when I got a proper heater block and installed the thermistor inside it, the temps went up to 210°-215°.

The E3D type all metal hot ends tend to work at higher temps primarily because they don't have any pockets of molten plastic like the the MG does, so they need the plastic at higher temps to keep it flowing.

The original SD hot ends don't really run cooler...it's just that the proximity of the thermistor to the melt zone was greater.  So while the hot end is actually running at, say 235; the thermistor reads 195-200 due to the farther distance.

350C is WAY too much - Thermistors will be damaged over 300C. I set mine at 295C after doing a PID tune to stabilize temps.

if you want to go 300C or more you will need to install a thermocouple setup

Last night I finally found the root cause of the filament feed issues.

When I fitted the Hobb-Goblin, I fitted it too far forward -- it wasn't aligned with the PTFE tube. So when it was feeding filament, it was constantly trying to push it forward out of the front of the extruder.

I've also found the problem with the Chinese filament: when it was spooled, it was tangled in several places. I've unwound a few (tens of) metres, untangled it, and rewound it properly. Now my SD is feeding filament correctly!

Oh well. At least I have a few extra rolls of filament now... and it's nice to have something other than black to play with. The only problem I've got now is that models are peeling at the corners. Printing a raft around them is helping a little, but not as much as I'd have hoped.