Unresolved Shuddering/jittering; bumpy on curved edges

Okay, so I thought I finally had the Robo working well, but I was wrong... the vertical Z-ribbing/banding issue seems to be fixed (presumably due to firmware upgrade) and the printer works fine on straight runs... BUT whenever curves get involved, this is what happens:

Sometimes (often, but not always), the carriage starts "jittering"... it shakes/trembles slightly, and make vibrating/shivering noises. This is also affecting the print... circles and curves end up being very rough/bumpy.

This never used to happen, until I replaced the hotend and updated the firmware to V2... any ideas? Again, it doesn't happen when doing straight lines... but happens about 50% of the time (maybe more) on curves...
I have had this problem with 2 different filaments, on 2 different models now (the whistle -- printed on medium -- and the robot, which was printed on low quality)

 

Ok that looks a little bit like over extrusion. Have you calibrated your extruder?

 

It's not overextrusion. Everything is the same as it was on that nearly-perfect calibration box i posted pics of. Also, if it were overextrusion, why would it only happen on curves... not straight lines? And why would it only happen sometimes -- not all the time -- on the curves? (At first I thought it could have something to do with the bed movement, but the straight lines are good even on diagonals, so there goes that theory)

it literally, physically shakes/vibrates when these issues are occurring (my wife even said "the printer sounds funny".. and that coincided with this artifact... i took a video, you might be able to see/hear it) Rather than having nice, smooth movement, it jerks and vibrates. I can't see any way that extrusion amounts would cause that behavior

 

Have you tried a different slicer? On the first picture, the jiggles look too uniform to make me think that it's just random, like a loose cable or something.

If you're using Slic3r or another one of the more advanced slicers, I've seen some options for using the firmware to make arcs instead of multiple segments. Could you have something like that set?

I'd also be suspect of some binding somewhere on the X or Y axis, but again, they look too uniform to me to be a hardware issue. Then again, I'm so new to this hobby that I'm probably pretty off base with my suspicions. I also remember reading somewhere about the printer having resonant frequencies that can cause issues.

I'd try a different slicer, or adjust the speed up or down a bit to see if the problem goes away.

 

Yeah I was also thinking it might be slicer related. Try cura

 

I will try whistle with cura.

thing is... i never used to have this problem with matterslice. It didn't occur until i replaced hotend (with identical setup) and updated firmware...

 

I've never used matterslice so I can't speak for it, but stranger things have happened. What's the name of the firmware you're running right now?

 

R1v2

MatterControl says it is up to date, but based on the Robo website and what someother forum posts have said, I'm not so sure.... (it sounds like they are up to v5)

 

Which solved the banding issue, but now I have this one (just as annoying, if not worse)

 

I've used both firmware versions (current using the MatterControl latest) and have also swapped my hot end with another hexagon and I've never seen that problem. I don't think it's firmware-related, unless you've got some slicer settings that conflict with the firmware.

 

There's different models out there of the robo and the firmwares have different names. It's pretty poorly managed but R1V2 is the latest for you. v5's were for beta printers

 

I wouldn't call the whistle "advanced"...

Also, our tablet stand that we developed is just a simple shape (triangles/rectangles), extruded up 3" on the z axis. Yet Slic3r can't even slice it! Always takes several minutes to "write file", and then it fails. Can't even make it work. MatterSlice handles it in seconds.

haven't tried cura yet, though. I'm about to give it a try

 

I was printing a new fan shroud last night and tried Slic3r first. It took forever to slice, came out looking nasty yellow/brown with natural PLA, and was ultimately unusable. It had a couple of nice supports, but a couple of really bad ones, too.

I ran it again using MatterSlicer. It sliced in seconds, came out frosted white with natural PLA, had minimal support (which apparently was all it needed) and I'm getting ready to mount it.

Both prints took about 3.5 hours, so I have no clue why the Slic3r print came out discolored. The temperatures were the same for both prints.

I've made some relatively complicated things, though I'm not sure how advanced we're talking about.

 

I have been thinking about the different slicers is it possible that one needs more processing power then another could that be why its slow?

I tried using Simplify3d and it looks a little over my head. Same with Cura, MaterControl seems by far the easiest to get going. Materslice never fails to slice a piece but the prints don't turn out very well some times. CuraEngine in MC fails a bunch but when it works the prints are much better.

My best prints come from MC running CuraEngine.