Solved Two steps forward, one back...extrusion issues

So I just got my replacement hot-end for my R1+ and the good news is, it appears to be working just fine (thanks, Robo support).

However, the issue that I noticed when I first got the printer has returned: specifically gaps in the printing. This weekend I printed a few things. On Saturday I printed a Fortune Cat, which came out OK except it had the gaps I'll show in a different print below. That was printed at 200m. Since that was the first print of any size (other than a 3mm calibration cube), I assumed it was just the nozzle getting acclimated. Unlike when I got the printer, I now have an oiler...and I could see the oil on the filament as it went through. My next print was the same Fortune Cat (from thingiverse) at 100m. It was printing perfectly until Simplify3D crashed on me, but it looked perfect (no gaps that i noticed).

So I rebooted my PC, printed a calibration print from thingiverse (after I noticed the z-axis was a little wonky) to make sure everything was cool. I then printed a Yarn Bowl to do a print that was larger than something I could print on my Printrbot. Due to the time, I decided to go to 300m (knowing full well there would be a quality drop). Unfortunately, the banding-gap problem came back. I saw this go away after I added the oiler, but it came back. I'm not sure what would make that happen. Any ideas what might be causing this? Could I be using too much oil? Could this be a temperature issue? I'm assuming this is related in some way to how the R1+ print mechanism works versus how my Printrbot works, since I've never seen this issue with that printer, even though they sit literally side-by-side.

Any suggestions are appreciated.

 

Sorry, realized I forgot to give details about some of my print settings.

This was printed from Simplify3D at 300m.
Print temperature was 210.
Filament type is ColorFabb PLA.
Extrusion is at .90, which is S3D's default for the Robo.
I'm not at the printer, so I can't recall what the retraction settings are, but I can post them later.

Could this simply be a question of under-extrusion? I can try a print tonight and increase that value, though I thought I did that prior to the oiler and it didn't solve it.

Thanks!

 

I go by if there is enough oil where it just puts a shine on the filament. Some say there is no such thing as too much. Either way really. With the new hotend, did you go through and do a PID tune or an extrusion calibration? Just want to make sure you aren't having an issue with under extrusion. Also did you season the new hotend prior to printing?

 

I also try to keep PLA printing at the lowest temp that it will extrude at. Somewhere between 190-200C for the hatchbox pla I've used. I don't think that is the root of your issue, but wanted to mention that since I saw you printing at 210C.

 

I have not (actually this is the first time I've heard of PID tuning, tbh). I can certainly give those a try. I didn't season the new hot end...I assumed that having the oiler would prevent me from needing to do so. Seasoning is basically just feeding through something like 50mm of oiled filament and then cooling down, heating up and repeating a few times?

 

Seasoning I normally dip the end of my filament into the oil and then run it through. More oil than I would be sending from the oiler.

PID tuning is fairly easy. Just send M303 E0 S190 C10 from the terminal window. The S190 is if you regularly print at 190C. Change that for whatever you normally print at. Then you take the last 3 values that it spits out (it cycles a few times) and enter that into the firmware and reload the firmware.

http://reprap.org/wiki/G-code#M303:_Run_PID_tuning

 

I tried printing at 200 and I believe saw no difference, but I'll try dropping down to the bottom end of the range, which is 190 for that filament.

 

and don't forget to do the extruder calibration. Need help with that then I can post the video we all know and love from our pal Tom on YouTube.

 

Tom Salander? Yup, I think I know the one. If not for his videos, I might never have assembled my Printrbot.

 

Good ol' Tom...He must be the most referenced youtuber out there for 3d printing

 

Okay, did a calibration last night and definitely saw progress, but I'll need to do more tonight. I believe it was extruding on 96mm when instructed to send 100mm, and I think I still need to increase it. I also lowered my print temperature to 190 and increased my extrusion multiplier to .95 from .90. The two prints below show the difference...the one on the left is printed at 100m with the new settings, while the other one was printed over the weekend at 200m with the old settings. The side profile shows the improvement more dramatically, but I'm still seeing under-extrusion on some layers, so I'll do some more tinkering.

Thanks for the advice, all.

 

If 190 isn't getting you what you needed for extrusion you might want to bump it up by 5C and try again.

 

Guys, can a partial clog cause something like this?
Would changing out to a new nozzle be worth a try?

 

my guess is that not the issue: I just replaced the entire hotend (including a new nozzle), which solved my previous problem of jamming above the heat break. I suspect it's just environmental issues, but I haven't had time in the last two days to really test some new settings. Hopefully tomorrow I'll be able to go ham on the printer and tune the settings. I think the extrusion is still too low, so I just need to further calibrate the extruder and possibly increase the multiplier. I feel like I'm getting close to having it working. (crosses fingers)

 

I've done a little more printing, including some ABS. I'm inclined to think it's really just tuning and other options now, so I'll close this thread. I'm going to do some more serious tuning this weekend.

Thanks, all!