Switching from S3D to Cura, help needed

[karnalta 0]

Hello all,

 

I would like to switch from Simplify3D to Cura but I struggling to find correct settings to get my print quality back.

 

My printer is based on a BLV MGN Cube and I print with a Volcano hotend + 0.6mm nozzle.

 

So far, I have try to transpose all my S3D parameters to Cura, most of them look straight forward but I feel that they are not .. There is a lot more parameters in Cura than in S3D, I feel like S3D is hiding a lot of stuffs behind the scene.

 

So far I have :

 

- Set my layers height and width the same.

- Set my temperatures the same.

- Set my speed a bit slower than in S3D because S3D seem to print slower than expected while Cura respect the entered speed.

- Set my retraction settings exactly the same.

- Set my fans settings the same also.

- Tried to mimic "wipe nozzle" + "only wipe on outer-most perimeers" S3D setting by using "outer wall wipe distance" of Cura.

- Enabled coasting and convert my 0.2mm in S3D to 0.26mm3 in Cura.

- All theses changes has each time increased my print quality (initials one with the default BLV MGN profil were catastrophics).

 

Now, I am getting a perfect first layer (better than S3D) and an nearly equivalent top layer. But, for the outer wall, it's really worse. I am pretty sure Cura should be able to output the same quality but I need a bit of help with potentials problems I have here 🙂

 

Here is where I am so far :

 

 

- I have small holes here and there in my walls.

- Blobs on tiny sport.

- And most importantly, my layers looks all jaggy and non-uniform.

 

Any tips ?

 

Thank you.

[GregValiant 1,330]

There are a couple of things you should check.

Make sure the "Wall Order" is set to "Inside to Outside".

Try a print with "Coasting" turned off.  It can cause dry starts as it allows the pressure in the nozzle to fall off.

Turn off "Retract at Layer Change" and "Retract before outer wall".

 

If you load the model and set Cura up to slice and then use the "File | Save Project" command and post the 3mf file here someone will take a look.  A Cura project file contains your printer, all the Cura settings, and the model.  It's a good one for troubleshooting.

[karnalta 0]

2 hours ago, GregValiant said:

There are a couple of things you should check.

Make sure the "Wall Order" is set to "Inside to Outside".

Try a print with "Coasting" turned off.  It can cause dry starts as it allows the pressure in the nozzle to fall off.

Turn off "Retract at Layer Change" and "Retract before outer wall".

 

If you load the model and set Cura up to slice and then use the "File | Save Project" command and post the 3mf file here someone will take a look.  A Cura project file contains your printer, all the Cura settings, and the model.  It's a good one for troubleshooting.

 

Thank you, 

 

Wall order is correct but I have made another change in wall parameter that improved the quality. Instead of using only one outer wall like I was doing in S3D, I used 2 and reduced the infill overlap from 15% to 10%. I have a lot less deformations on my wall now.

 

I will try to turn off retract settings you're talking about. But for coasting I have more doubts because it has helped a lot with the quality  when I have activate it. I should have specify that my printer is a bowed extruder.

 

Here is my project file so far.

BLVMGNC300_xyzCalibration_cube.3mf

 

EDIT :

 

I unchecked "Retract between layers" and "Retract before outer wall" was already unchecked. It has again increased my print quality. I am almost there 🙂

 

 

I still have a bit of blob inside the "X" and the bridging is still a bit flappy. But honestly, picture is worse than reality. For bridging I don't know what I could do more, I have already set fan at 100% for bridging.

 

I will make another attempt by reducing a bit coasting amount.

Edited December 20, 2022 by karnalta

[GregValiant 1,330]

With the fairly fine detail on the block and a .6 nozzle you might consider dropping the line width to .6 and the layer height to .2.  That should eliminate the droopy look around the letters.  A large model is one thing to print with coarse settings, but for that block with that bit of detail and some unsupported overhangs on the side letters - going finer is a good idea.

I don't really see a "bridge" issue there and in fact I wouldn't bother to turn it on.  Spanning multiple centimeters is one thing but the tops of those letters a couple of mm's.  You shouldn't need the bridge settings for that.  I don't use coasting as I've found it produces more problems than it solves.  It can make skins look somewhat better, but the monotonic setting is superior (but can produce a lot of travel on certain models).

 

Your "Outer Wall Wipe Distance" of 5.0 in not good.  1/4 to 1/2 nozzle width would be WAY better so drop that setting to 0.15 to 0.30.

I generally consider 3 walls and 4 top/bottom layers to be a minimum to keep infill from showing through.  That varies by model but it's a decent general rule.  I print mostly functional things and strength is usually high on my list of priorities.

You have "Avoid Printed Parts" and "Avoid Supports" enabled in the travel section.  Sometimes it's best to leave those disabled because Cura will calculate travel moves off the part.  That's nice, but it also means that on some models the nozzle will drag off the print as it leaves, and then drag back on when it comes back.  Those moves can leave marks so on a single print it's best to leave them off.

 

 

I looked at the definition file for your printer.  It inherits the BLV_MGN_Cube base file which in turn inherits the Anet3D definition file.  There is an oddity in there...the Anet definition file states that your Max Accel on the X and Y is 500 but the same definition file also sets the Accel in Cura to 1000 so it's 2X the maximum.  There is no way to tell what the Max is in the printer without sending an M503 and checking the printer response.

 

There are other things I would change but it's mostly personal preference and what works on my Ender.  For a 0.6  or 0.8 nozzle I scale up the cube to 30mm.  It gives the bigger nozzle a better chance of making a nice print.  Particularly with the 0.8 nozzle, I've found that some "Extra Prime" is required as on large models there are long travel moves and the nozzle pressure will fall off and the start of an extrusion will be under-extruded without an extra kick.

 

Usually with PETG having the layer cooling blower on near the bed is a bad idea.  Long thin sections will definitely lift from the bed.  I've written myself a post-processor so I can adjust the fan speed either by layer or by feature but generally I don't run the fan below about layer 50 of whatever I'm printing in PETG.  For the most part, PLA just doesn't care.

Good Luck with it.

 

 

 

 

 

 

[karnalta 0]

10 hours ago, GregValiant said:

With the fairly fine detail on the block and a .6 nozzle you might consider dropping the line width to .6 and the layer height to .2.  That should eliminate the droopy look around the letters.  A large model is one thing to print with coarse settings, but for that block with that bit of detail and some unsupported overhangs on the side letters - going finer is a good idea.

I don't really see a "bridge" issue there and in fact I wouldn't bother to turn it on.  Spanning multiple centimeters is one thing but the tops of those letters a couple of mm's.  You shouldn't need the bridge settings for that.  I don't use coasting as I've found it produces more problems than it solves.  It can make skins look somewhat better, but the monotonic setting is superior (but can produce a lot of travel on certain models).

 

Your "Outer Wall Wipe Distance" of 5.0 in not good.  1/4 to 1/2 nozzle width would be WAY better so drop that setting to 0.15 to 0.30.

I generally consider 3 walls and 4 top/bottom layers to be a minimum to keep infill from showing through.  That varies by model but it's a decent general rule.  I print mostly functional things and strength is usually high on my list of priorities.

You have "Avoid Printed Parts" and "Avoid Supports" enabled in the travel section.  Sometimes it's best to leave those disabled because Cura will calculate travel moves off the part.  That's nice, but it also means that on some models the nozzle will drag off the print as it leaves, and then drag back on when it comes back.  Those moves can leave marks so on a single print it's best to leave them off.

 

 

I looked at the definition file for your printer.  It inherits the BLV_MGN_Cube base file which in turn inherits the Anet3D definition file.  There is an oddity in there...the Anet definition file states that your Max Accel on the X and Y is 500 but the same definition file also sets the Accel in Cura to 1000 so it's 2X the maximum.  There is no way to tell what the Max is in the printer without sending an M503 and checking the printer response.

 

There are other things I would change but it's mostly personal preference and what works on my Ender.  For a 0.6  or 0.8 nozzle I scale up the cube to 30mm.  It gives the bigger nozzle a better chance of making a nice print.  Particularly with the 0.8 nozzle, I've found that some "Extra Prime" is required as on large models there are long travel moves and the nozzle pressure will fall off and the start of an extrusion will be under-extruded without an extra kick.

 

Usually with PETG having the layer cooling blower on near the bed is a bad idea.  Long thin sections will definitely lift from the bed.  I've written myself a post-processor so I can adjust the fan speed either by layer or by feature but generally I don't run the fan below about layer 50 of whatever I'm printing in PETG.  For the most part, PLA just doesn't care.

Good Luck with it.

 

Hello Greg,

 

Thank for your detailed reply.

 

The fact I have print this small cube with 0.6 nozzle and that layer height/width combination is because this is how I have printed it in S3D. The goal was to have a one to one comparison with Cura quality.

 

For the "Outer Wall Wipe Distance", that the one setting where default Cura value (sub millimeter) was miles away from what I had in S3D, I have set it as in S3D without having really any clue on the impact to be honest 🙂

 

I will give a try at unchecking "Avoid printed part". I guest depending on the model, it can make it better or worse.

 

About my printer definition I don't really know, BLV has nothing to do with a Anet3D, probably the guy who created the Cura profile has use it as a random base. BLV has been entirely designed by Ben Levi, it's really a great printer (I don't know if you have google it or if you already know it).

 

95% of what I print are mechanical parts in PETG with my 0.6mm nozzle. So where I am with my XYZ cube quality at the moment it's quite good enough. My print are generally at least 5-6 times the volume of that cube. I am now benching a bit the stringing with that small two-towers model. I have a lot of it ATM compared to S3D, I will dig a bit in retraction and coasting.