Help Printing Problems

[gustrowsky 0]

Hello everyone. I am 3d printing this piece and I am getting some issues I can't find solutions for. I have images attached. Thank you!  

[GregValiant 1,410]

If you would use the File | Save Project command you'll generate a 3mf file with all your settings in it.  Post that 3mf file here and somebody will take a look.  Without knowing any of your settings it's just guessing.

[gustrowsky 0]

Here is my file. Thank you for your support!

BB-8 skeleton file.3mf

[GregValiant 1,410]

You don't need my support...I've seen your customs supports.  There is a lot of effort into that.

I hope @gr5 chips in with his thoughts.  I get first shot at it though.

 

This is necessarily a lot of opinion/personal preference so don't take any offense.

• The 1.4mm line width for the initial layer is huge.  That is an effective flow rate of 350%.  I know you've got it going very slow at 12 and 15mm/sec, but that's a lot of plastic to push.
• That amount of plastic flow coupled with an initial print temperature of 170° is making your printer work really hard to get plastic out.  At the regular printing temp of 180° the layer adhesion can't be anything to write home about either.  I print white PLA the coolest of any material I've used and I print it at 200°.  This may be one of those "personal preference" things.  You know your machine.
• "Compensate Wall Overlaps" could be one of the problems you are having with corners.  The plan is that when walls pass close together, the extrusion is lessened to prevent over-extruding.  That means in some cases that it's under-extruding and doing it on purpose.  It's a feature that has a use in specific situations but I don't see a need for it on those parts.
• Z-hop.  At a height of only .075mm, why not just turn it off.  The print head is jumping up and down and really not having much of an effect other than inducing vibrations.  It can also cause extrusion problems in the area between holes or other features that are on the same layer.
• Combing.  Long combing moves allow the pressure in the nozzle to fall off.  When the "prime" comes and extrusion resumes the prime is often insufficient to meet the immediate needs of the next extrusion line.  That results in under-extrusion for a bit before the pressure can build back up.  This is usually more of a problem at the layer start and at the zseam location because so many prime moves take place there.
• Finally, you have 50% density gyroid infill coupled with slow print speed and all the combing moves on three parts.  It's a 54 hour print.  Why not print one at a time?  The total print time won't be much different and the threat of one piece failing after 30 hours and taking the other two with it becomes nil.
• In your photos #2 and #3, that edge needs to be supported.  You have given a lot of attention to support on the back side, but on each "front" corner, the printer is air-printing that edge.
• The printing temperature of 180° may have something to do with the bridging problem in the c'bored hole.
• In photo #4 those blobs happened when the nozzle made turns at the start of a layer, or at the Z seam.  There is going to be some visible "stepping" along that edge since it's a sharp corner along a compound curve. 

Using up some leftover wet filament (it's why I keep it around), I did a partial print.  This is with 0% infill, 200° print temp, 50mm/sec printing speed, combing off, "Compensate Overlaps" off, Z-hops off.  I moved the model down 35mm into the bed to avoid all the support.

As is typical when I print white PLA, there was some wispiness, but no real stringing.  There were no surface blobs.  It took 3 hours.

 

Have you printed a temperature tower to confirm that your machine prints well at 180° (as opposed to 195 or 200)?

[gustrowsky 0]

Thanks so much for your help. I will try the printing tower and thanks for helping. I will share my results soon.

[gustrowsky 0]

 So, I have one perfect corner and one messed-up one. Would re-leveling fix this? 

[GregValiant 1,410]

No, the problem occurs well off the bed.  Do you have combiing or coasting enabled?  It looks like it might be having trouble getting the extrusion to start when it comes around that bad corner.

 

If you could use File | Save Project and post the 3mf file that would be good.

[gustrowsky 0]

I have combing and coasting off... 

 

 

InnerSkeletonV1.3mf

[GregValiant 1,410]

There are things in your settings I would do differently, but they are just personal preference.  Nothing sticks out as interfering with other settings.

While I was sitting here watching my machine come to a color change I played with your model.  Again, it's just personal preferences but it's how I would do it.

GV_InnerSkeletonV1.3mf

[gustrowsky 0]

Thanks for those settings. They're probably better than mine anyway 🙂 How do I get rid of that grey box around the print? I want to print the whole thing. Thanks for everything!

[GregValiant 1,410]

There are "different" settings but there are no "better" settings.  We just do the best we can.

 

There are 2 1/2 kinds of gray areas.

#1. Is around the periphery of the build surface and is reserved for skirt/brim.  If you change the skirt settings or the brim width that gray area will change size.  If you set Build Plate Adhesion to None that gray area will disappear.

#2. Is around the model itself - sometimes.  When you print "All at Once" there will be no gray area around the model.  If you print "One at a Time" then Cura takes into account the size of the print head and limits where you can place models.  It represents the interference area of the print head.  Cura also takes into consideration the Gantry Height which is usually the distance from the top of the bed to the underside of the X beam.  If a part is taller than "gantry height" it won't slice as Cura considers a possible crash between a finished part and the gantry.

#1/2 is on Creality printers.  It is defined as a stripe on the front edge and on the back edge of the build plate that is reserved for the clips that hold the glass build surface to the hot plate.  The defined area is in the printer definition file and I remove it for my printer as I don't use clips.

[gustrowsky 0]

This box. I think it's there because you are only printing the top 3/4.

[GregValiant 1,410]

It is a generic support blocker for all the upper holes.  I figure they would bridge OK and not require support.

 

Slice it with it in there and see what the supports look like.  Then select just the support blocker, delete it, and slice again.  You will see the difference as a bunch of additional supports grow up and into the holes.