Cura 4.13.1 - Newbie doing something wrong!

[zogthegreat 0]

Hi everyone!

 

So I'm the proud owner of a new Ender 3 Pro! 😊 However, I'm having a problem with Cura. When I slice my .stl, my print comes out as sort of a mesh, (please feel free to help me with the terminology here). Here's a picture of what's going on:

 

 

When I print the precompiled .gcode that came with the printer, it prints perfectly, however, as you can see, when use Cure to output the .gcode, it comes out like garbage. I tried raising my infill to 100%, but I have the same results. I'm sure that this is a PEBKAC, but I can't seem to find any settings to fix this problem. Here is the link to the original .stl:

 

https://www.thingiverse.com/thing:1895060

 

Any suggestions?

 

Thanks!

 

zog

[GregValiant 1,261]

I've been living with my Ender 3 Pro for a couple of years now.  Any printer and the slicer have to be on the same page when it comes to reading a gcode file  In your case look in Manage Printers and Machine Settings and check the firmware Flavor.  It should be set to Marlin (and NOT Marlin Volumetric).  Within the printer menus will be a setting for Control and Filament.  "E in mm³" needs to be Off.

If both the slicer and the printer are set to Volumetric (E in mm³) then it's OK.  When one is different than the other it doesn't work.  That is a setting used by people with a couple of different printers and one might be 1.75mm filament and another 2.85mm filament.  If they don't know which printer will get the job then Volumetric will work.

 

If you haven't done so you need to calibrate the E-steps so that when 100mm of filament is asked for, then exactly 100 is pushed by the extruder.  There are a lot of videos on how to do that.  I don't believe in Calibration cubes.  Setting the E-steps is all that is needed.

 

I think the problem is the volumetric settings aren't in sync between the printer and Cura.

 

EDIT:  If your printer has a plastic extruder arm then take it off and check the underside to see if it's cracked.  They don't hold up and some Enders have even been delivered with cracked arms.  Talk about a short lifespan!

Edited February 10, 2022 by GregValiant

[zogthegreat 0]

Hi @GregValiant

 

Sorry for the late response, I've been working on getting my printer printing properly and I'm confidant that you know what a PITA that is!

 

Thanks for the advice. I've calibrated my e-steps and now my printer is extruding properly. I was off by 27.41, so not that bad, but still enough to mess with my prints.

 

Right now I'm working on getting my bed calibrated, however that's on hold until a glass bed arrives from Dr. Evil's lair, (I'm sorry, but if Jeff Bezos want's to shave his head and build a moon base, he qualifies as Dr. Evil!). As soon as it comes in, I'll level my bed and try printing again.

 

A question that I have is I thought that the CR Touch was supposed to eliminate the need for bed leveling. Why is it necessary to manually level the bed if I have a CR Touch installed?

 

Thanks again for the help!

 

zog

[GregValiant 1,261]

Remember - the printer doesn't know where the bed is and neither does Cura.  The bed needs an initial leveling.

The ABL system doesn't move the bed up and down, it simply creates a virtual grid showing where the bed is high or low.  The firmware then adjusts the first layer to the grid.  It won't make an adjustment if the bed is off by 10mm.

Once you have the initial leveling close then the ABL should work.  You might have to do (manually level) again once in a while, but not every print.

[gr5 2,178]

Also the leveling firmware moves the Z axis up and down as it prints the first layer (which is not flat but matches the hills and valleys of the glass) and slowly reduces the corrections to zero by the 10th layer or so.  If your bed is quite a bit off this will give wedge shaped bottoms of your parts.  Like if you print a cube the bottom face will be crooked.

 

So you need to get it pretty close manually once time and then forget about it for a few years.

[zogthegreat 0]

So things seem to be working now. I installed my new glass bed and reset my z axis properly. Now I'm getting good printing results"

 

 

It looks like I need to tune my Y axis a bit, my test print came out somewhat forward instead of centered. I alos have a minor problem with stringing, but it looks like I'm finally getting my printer zeroed in!

[GregValiant 1,261]

"my test print came out somewhat forward instead of centered."

This is a popular one.

Get out a thin metric ruler.

Auto-Home the print head.

Raise the Z 5mm or so.

Move the X until the nozzle is 2.5mm in from the left edge of the glass (not the bevel, the edge).

Move the Y until the nozzle is 2.5mm in from the front edge of the glass.

Lower the Z to 0.

On the LCD select Set Home Offset and then Save Settings.

In Cura, go to Manage Printers and then Machine Settings.  Set the build plate to X(width) = 230 and Y(depth) = 230.

 

That's it.  Now both the printer and Cura know where to start printing from.  The midpoint of your glass will be X=115 and Y=115.

[zogthegreat 0]

@GregValiant

I am trying to do as you suggested with setting the offsets, however, after I do my measurements and try to "Set Home Offset", I get an error on the main screen "Err: Too Far".

 

I've tried nudging the X & Y axis by 1mm in, but I get the same error.

[GregValiant 1,261]

That shouldn't happen.  I have the same printer (although mine is a couple of years old).

Auto-home the print head and measure the distance from the nozzle to the edge of the glass.  Post the X distance and the Y distance.  Neither should be more than a couple of mm.

I have set my home offset to the right front corner when I needed to mirror a gcode file one time.  Your newer firmware is likely configured differently, but it shouldn't be that different.

 

The printer looks at a gcode file and puts the origin at the Home Offset position.  Right now since you haven't defined the Home Offset position the origin is at the Auto-Home position and so the prints aren't centered.

 

Another thing to look at is to:  Auto-Home and then move the print head to X=235 and Y=235.  Can it get there?  At that point the nozzle should be just inside the right rear corner as the Auto Home position is outside the left front corner.

[zogthegreat 0]

OK, this is probably where, (one), of my problems is. When I hit auto home, my printer extruder goes to the center of the machine. Since this is how it was coming out of the box, I assumed that this was set in Marlin and everything was properly configured.

 

I'm going to do some Googling today on how to properly set the offsets and I will post up my results.

[GregValiant 1,261]

Yours is the first Ender I've heard of that Auto-Homes to the middle of the build surface.  The typical situation is to hit the End Stop Switches in the X, Y, and Z.  All three switches are mounted so they are hit when the print head is at the left front corner.

So where are the X and Y switches mounted?  On my printer - the X switch is mounted on the X motor housing and is tripped by the print head bracket.  The Y switch is at the back of the Y beam and is tripped by the right rear wheel on the Y carriage.  After Auot-Homing, my print carriage stays right there in the left front corner.

 

 

[zogthegreat 0]

So I think I have my bed calibrated properly(ish):

 

 

I still need to tweak it to the rear a bit, it's still forward about 3mm. Having said that, the machine printed out the test pattern and everything was evenly printed out. I'm going to try an actual print and see how it goes.

[GregValiant 1,261]

Close enough.  Print stuff.

If you get a model that is the size of the build surface there may be a problem, but with most models it should be fine.

[zogthegreat 0]

So success, (mostly). I ran a print through and I got meh, OK results:

 

 

Obviously I have some Googling and tweaking to do but I am printing and my print is centered and adhering to the bed.

 

Thanks for the help @GregValiant, really appreciate it!

 

[EDIT] This print was done with eSun PETG @80c for the bed and initially 240 for the extruder. I started having strings and I lowered the extruder to 235. However, that's when the print started getting the rougher appearance. 

Edited February 21, 2022 by zogthegreat

[GregValiant 1,261]

PETG is just gooey.  There is usually a little more cleanup on a print than with PLA.  My numbers are the same as yours at 240/80 with 6.5 retraction at 35.  I think I get better layer adhesion at 240 so I leave it there.  My print speed is 35 with 30 for the outer walls.

 

[GregValiant 1,261]

Z-hops.  That print appears to be a "U" shape.  A combing mode that stays over the part is a good idea but if Z-hops are enabled then the nozzle lifts and so does a string.  The nozzle may travel over the part, but the string stays pretty much in a straight line from the nozzle lift point to the nozzle drop point.  That will leave more cleanup.  Better to leave Z-hops off and allow the nozzle to wipe itself as it travels over the part.  Large horseshoe shapes present problems because of the long combing moves.  The pressure in the nozzle falls off and the next extrusion can take a few mm's to get going while the pressure builds again.  There is a post-processor called "Retract Continue" that spreads the retraction across the combing move rather than all at once.  It takes some tweaking to get it right but it's handy.  It doesn't work with Z-hops enabled.

[zogthegreat 0]

I just ran a retraction test with this model:

 

Quick Stringing / Retraction Test

 

Here is my results:

 

 

I'll try to make the changes that you recommended to my Cura settings.

 

BTW, since I'm a beginner, would I be better off with ABS instead of PETG? I'm nervous about PLA due to it's sensitivity to heat.

[zogthegreat 0]

I went into Cura and found the z hop settings. The only thing that I could change was the z hop speed, which I set to 0:

 

 

I ran another test print and I have better results now:

 

 

Gaa! I understand that there are a lot of variables in 3D printing, room temp, ambient humidity etc, but I can't wait until these thing just plug in and work!  

[GregValiant 1,261]

"I can't wait until these thing just plug in and work!"  

 

There is no "Easy" button.

 

That test is much better.  I use very little fan with PETG because certain shapes will warp/pull from the bed but that print looks like you can do with some cooling.

 

ABS gives off noxious fumes, and is a lot fussier to print.  An enclosure is pretty much a must-have.  PLA might not be what you want to make some models out of (It isn't good at in-car phone holders for sure) but it is easy to print and you will learn a lot from it.  Printing knowledge will transfer over to PETG.

 

I was having trouble finding my silver SUV among the other thousands of silver SUV's in parking lots.  This is a shark fin for the roof in silver PETG.  I made other ones in PLA and yes, they were a problem.  So I developed the steel backbone.  It slides down into a hole and then the print finishes.

You can see that in spite of the robust elephant ears it was pulling up hard.

 

[zogthegreat 0]

Wow! That's really nice work! I didn't know that you could embed objects into the print as it was printing.

 

I tried to start my day with PLA, however, I accidentally loaded some HIPS in to my filament dryer. I have to dry the filament that I'm using because it's over 5 years old and has been sitting in a box, in my balcony storage closet, with temperature swings of 35c in the summer and -25c in the winter! I managed to get a so-so print out of it, but bed adhesion was a problem;

 

 

 

I'm putting the HIPS back into the box until my skill level goes up. 

 

Once the PLA was dry, I was able to get some really good quality prints, although I had some very minor lifting on one corner:

 

 

Other than that, a really nice job;

 

 

 

Thanks for all of your help @GregValiant!

 

 

[GregValiant 1,261]

Cura's Pause at Height plugin makes the hobby much more interesting.  I don't bother with the retraction settings in it.  I just tell it what layer to pause at (layer numbers in gcode are base 0 and in Cura they are base 1) and where to park the head.  After I have hand pushed some filament through to flush the first color I "hand retract" about 3mm and then click the LCD button to resume the print.  I've gotten pretty good at faultless restarts.

You can insert nuts, bolts, whatever using Pause at Height.  You can change colors at a layer.  By designing parts with "steps" in a top surface you can change filament and make some sophisticated prints.

This was for a friend.  This sort of thing is all about practice and thinking about possibilities.  Getting good at a CAD program that you can export STL/OBJ/3mf etc. model files from is a good idea or you just get stuck printing stuff from Thingiverse.

 

 

Speaking of inserting nuts - if you design your own parts you can get threaded inserts that you heat with a soldering iron and push into a hole in a print.  When the plastic hardens back up it grips the insert.  McMaster Carr here in the States sells these.  I used my electronics soldering iron as a push tool.  The narrow tip slipped right into the nut and the inserts went in perfectly straight.  The shark fins have four 10-24 nuts in them along with the steel backbone.  All those were inserted into hex shaped holes during a pause.

 

For being a good student and not disrupting the class, here is a printing utility I wrote.  It is for Windows only (Visual Basic doesn't port to other operating systems) and it isn't signed so you would have to fool your anti-virus into allowing you to install it.  There is a readme file in the zip folder.

It allows you to control printing from the SD card from a connected computer and moves a lot of regular things from the LCD to the computer.  It does not print over the USB, just sends commands to the printer telling it what to do and where to go.

 

Gregs SD Print Tool.zip

[zogthegreat 0]

Thanks @GregValiant! Right now my son can't find my Raspberry Pi, so I'm running Windows off of a Dell 9020 Micro to run my webcams for monitoring. I'll give you app a try as soon as my current print is done.... right now I'm on the tail end of a 15 hour print, so I don't want to breath anywhere near the printer in fear of messing something up!

 

I'll give it a try later and let you know how it went.

[GregValiant 1,261]

If the USB sees 5v it will cause the printer to reboot.  It's the emergency external reset.  Never connect during a print.