So.... What's happening to my corners?

I've tried A LOT of things and I can't seem to get anywhere.


Tell me what additional info you need:

PLA
185c nozzle
75c bed
200mms print speed (This is my goal speed and I'm NOT slowing down after all my BS prior to my new setup)


I just want to print............ And I feel a collective of minds can help me figure this out.

Edited 1 time(s). Last edit at 10/26/2015 09:10AM by Hephaestus0000.

200mm/s that is some speedprinting.

What type of printer is this?

Folger Crap Prusa I3
Flexidrive
ED3v6 hot end


For the record I halved the speed and the result was the same.

I personally don't have any experience with this type of printer but to be able to print at 100mm/s I think you need a printer with a lot less moving mass, like a delta.

Maybe someone else knows the upper limit for accurate printing with a prusa style printer?

But I'd try much slower first, like 30-40mm/s

Edited 1 time(s). Last edit at 10/26/2015 04:24PM by Koenig.

What size cube is that?

Most likely it's a combination of issues. Could be Vxy-jerk is too low versus print speed, what happens is that the build up pressure during fast print motions causes extra fikament to come out in the the corners. You'll need to keep that speed as constant as possible. This can be worse with a high temperature, backlash in the x y (with auto bed leveling also z) belt or idler and a wobbly y carriage.

I had a similar mess at much lower speeds, maybe you can check these to confirm it is not your hardware:
1. Check if the print bed vibrates - mine did on the mounting poles and it was only noicable when holding your fingers on the bed during prints.
2. Especially at higher speeds the moving mass of things can play tricks with you.
The belts can actually flex and expand a little bit and even with a belt tensioner you still have to provide more force to hold all in place than what is applied by the movement.
3. Extruder pressure...
The higher your print speeds the more constant you want the pressure to be in your nozzle.
On an item like the cube you can work without retraction to check if the problem is within those settings.
4. Overall flex of the printer frame.
Extreme speeds can cause extreme things Check if your printer is still sturdy and stable at high speeds.


Basically it comes down to do print at "very low" speeds of around 30mm/s and without retraction to check if the problem is in any way related to the speed you print at.
If at low speeds the result is as bad as before it comes down to tweaking the settings.
By the way, on my old Prusa I can only reach around 160mm/s with PLA before literally everything comes together to make a mess out of the print.
And I only use those speeds for test prints of simple parts, everything that needs half decent quality is printed at a max of 80mm/s.

it's a 20mm cubed cube


I'm pretty sure my speed has little to do with it because I just attempted to print another one at 30mm/s and there was absolutely ZERO difference.

Try to print the object without any kind of retraction, I have a hunch that would almost eliminate your problem.

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borupdk
Try to print the object without any kind of retraction, I have a hunch that would almost eliminate your problem.

At my intended speed goal or at a lower speed?

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Hephaestus0000

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borupdk
Try to print the object without any kind of retraction, I have a hunch that would almost eliminate your problem.

At my intended speed goal or at a lower speed?

Start at lower speed and when you get results that is acceptable to you - raise the speed.

For printing with PLA on blue tape, your heated bed temperature seems really high, transferring excess heat to the plastic. Try turning it down to 60º or less, or even turning it off entirely.

Nope.

Tried ZERO retraction and no bed heat at 30mm/s and I get the SAME result.

It's actually worse. A lot worse.

Edited 1 time(s). Last edit at 10/29/2015 07:59AM by Hephaestus0000.

OK, so you have ruled out retraction, that is one thing less at least.

You say it came out worse when you printed last time, how?

Is your extruder calibrated?

What does your slicer setting look like?

The corners on the left look much worse than the right corners.
I guess you have a fan blowing partly on your hotend?
-Olaf

Cubes aligned with XY are hard because at the corner one axis has to go from Vjerk to 0 instantly while the other goes from 0 to Vjerk instantly. The entry and exit to the corners also have to decelerate and accelerate between Vjerk and Vperimeter, so the print head has to cope both with the physical forces and the change in pressure due to the changing extrusion rate.

Which is a long winded way of saying you might want to experiment with different values of the jerk speed, and it would be interesting to compare the normal print with one where the cube is rotated 45 degrees on the print bed.

I was also trying to estimate your layer thickness - it looks pretty small, less than 0.2mm? Experimenting with different layer thicknesses might provide interesting info. If the problem is, say, over extrusion in the corners it might be much less of an issue with thicker layers.

I printed this with FolgerSHIT i3 as well but at 150mm/s, but MK3 bed, Genuine E3D v6, Greg Wade Bowden Drive, and use newer firmware configured from scratch with autobed leveling enabled

I have't tried any faster yet, 150mm/s is good enough for me for now



p.s. leadscrew upgrade and this and that, its not really a FolgerSHIT anymore TBH and that hammer was printed with ABS by the way

Edited 2 time(s). Last edit at 10/29/2015 02:33PM by deaconfrost.

Yeah, I can print at 5000mm/s with acceleration set to 1mm/s²
-Olaf

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Koenig
OK, so you have ruled out retraction, that is one thing less at least.

You say it came out worse when you printed last time, how?

Is your extruder calibrated?

What does your slicer setting look like?

Yes my extruder is calibrated.

The corners were worse. I don't know how to really explain it. It was just.... Worse

Is there a faster, more efficient way of posting my slicer info rather than just screen capping everything?

Quote
o_lampe
The corners on the left look much worse than the right corners.
I guess you have a fan blowing partly on your hotend?
-Olaf

Nope

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JamesK
Cubes aligned with XY are hard because at the corner one axis has to go from Vjerk to 0 instantly while the other goes from 0 to Vjerk instantly. The entry and exit to the corners also have to decelerate and accelerate between Vjerk and Vperimeter, so the print head has to cope both with the physical forces and the change in pressure due to the changing extrusion rate.

Which is a long winded way of saying you might want to experiment with different values of the jerk speed, and it would be interesting to compare the normal print with one where the cube is rotated 45 degrees on the print bed.

I was also trying to estimate your layer thickness - it looks pretty small, less than 0.2mm? Experimenting with different layer thicknesses might provide interesting info. If the problem is, say, over extrusion in the corners it might be much less of an issue with thicker layers.

I'll try rotating it 45 degrees

I printed that cube at 0.2mm and any subsequent cubes related to this post.
However, I have tried printing the cube at:
0.25
0.22
0.20
0.175
0.15
0.125
0.1
0.05

And the smaller the layers became, the more of a mess it made.

Quote
deaconfrost
I printed this with FolgerSHIT i3 as well but at 150mm/s, but MK3 bed, Genuine E3D v6, Greg Wade Bowden Drive, and use newer firmware configured from scratch with autobed leveling enabled

I have't tried any faster yet, 150mm/s is good enough for me for now

[attachment 64939 20150928_221257_001.jpg]

p.s. leadscrew upgrade and this and that, its not really a FolgerSHIT anymore TBH and that hammer was printed with ABS by the way

That's really awesome, but it doesn't really help me and it just makes me jealous......

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o_lampe
Yeah, I can print at 5000mm/s with acceleration set to 1mm/s²
-Olaf

............ As does this

Quote
Hephaestus0000

Quote
o_lampe
Yeah, I can print at 5000mm/s with acceleration set to 1mm/s²
-Olaf

............ As does this

No need, he was making a bit of "fun", you can actually print however fast you like using an acceleration of 1mm/s, you won't reach that speed inside the bed boundaries anyway.

Many slicers include the settings as comments at the beginning of the gcode file that gets outputted, you can get them there.

Hi Hep, Pugzor posted a link in the pictorial print issue thread to simplify 3Ds troubleshooting guide, and I thought their entry on curling and rough corners looked quite a bit like yours.

[www.simplify3d.com]

Maybe worth taking a look at their suggestions? If that doesn't work out, perhaps it would be worth posting some more pics from a few different angles so that we can get a better look at what's going on.

the only thing I can tell you is I worked my way up slowly adjusting the settings starting fom 40mm/s and observe the changes of the result and adjust, again and again and again, think it was about 3 to 4 weeks of trying different settings and layer heights before I got to the result I feel acceptable.

here's what I have set in marlin for stepping and speed

are you using stock extruder mounted on x carriage with groove bearing?

I'm using greg's wade with bowden on the E3D v6

I had similar problem on wall due to extruder stepping

if you still on stock extruder, that would be first place to start, slow down and print yourself a gear extruder like greg's wade or go bowden

just noticed you using FlexiDrive, I have no experience with that, but would be the place to look at, as when I had the similar problem, it was the extrusion stepping that I corrected and the problem went away

#define DEFAULT_AXIS_STEPS_PER_UNIT   {80,80,4000,1260}  // default steps per unit for Ultimaker
#define DEFAULT_MAX_FEEDRATE          {500, 500, 3, 25}    // (mm/sec)
#define DEFAULT_MAX_ACCELERATION      {9000,9000,100,10000}    // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for Skeinforge 40+, for older versions raise them a lot.

#define DEFAULT_ACCELERATION          3000    // X, Y, Z and E acceleration in mm/s^2 for printing moves
#define DEFAULT_RETRACT_ACCELERATION  500    // E acceleration in mm/s^2 for retracts
#define DEFAULT_TRAVEL_ACCELERATION   3000    // X, Y, Z acceleration in mm/s^2 for travel (non printing) moves

// The speed change that does not require acceleration (i.e. the software might assume it can be done instantaneously)
#define DEFAULT_XYJERK                20.0    // (mm/sec)
#define DEFAULT_ZJERK                 0.4     // (mm/sec)
#define DEFAULT_EJERK                 5.0    // (mm/sec)

Edited 2 time(s). Last edit at 10/31/2015 05:16PM by deaconfrost.

Although some might not like it but anyway:
I think the problem with your prints is over extrusion.
Especially if finer layers get worse.
Keep in mind that a layer height below 0.1mm requires a perfect extruder calibration as otherwise there is always too much or too little plastic.
After the initial calibration using digital calipers I finetune the extrusion using solid infills.
The first layer needs to be perfectly adjusted in terms of bed flatness, print start height and so on.
If the second layer shows single lines with tiny gaps it needs more plastic.
Plastic being squshed out of the lines, building small blobs or higher, visible lines between the extrusions means too much plastic is used.
With the extrusion tuned right even a 0.5mm solid layer should have a shiny finnish with visible extrusion lines but no visible gaps or over extrusions.
Only once that is done I print serious things with a new roll of filament.

Of course you can print several layers and play with the extrusion multiplier on the go before going into the settings for a change.
But I noticed that for layer heights below 0.1mm you often need to use the "on the go" settings to go a few percent up and down.
A change from 0.92 to 0.93 in the extruder settings to adjust a tiny bit of under extrusion can be too much for small layer heights.
So instead the on the go percentage is adjusted before the print (or after the first layer) to 102 or 103 instead.
IMHO it is easier to do the the final tuning with the smallest layer height you intent to use, if that is fine all higher layer heights will be perfect anyway.

Quote
JamesK
Hi Hep, Pugzor posted a link in the pictorial print issue thread to simplify 3Ds troubleshooting guide, and I thought their entry on curling and rough corners looked quite a bit like yours.

[www.simplify3d.com]

Maybe worth taking a look at their suggestions? If that doesn't work out, perhaps it would be worth posting some more pics from a few different angles so that we can get a better look at what's going on.

That does looks incredibly similar to what I'm experiencing.
However, I only get a slight corner lift (not off the bed) in 3 put of 4 corners and then the last corner over extrudes like crazy.

I'd try taking more pics but my phone camera seriously dislikes my lighting.
I can almost never get a clear shot unless its overexposed.

Quote
deaconfrost
the only thing I can tell you is I worked my way up slowly adjusting the settings starting fom 40mm/s and observe the changes of the result and adjust, again and again and again, think it was about 3 to 4 weeks of trying different settings and layer heights before I got to the result I feel acceptable.

I'm going on 6 months trying to get this FolgerCrap to work decently and I've spent a lot of time and money doing so.