Help with a slic3r or scad problem

I have been modifying the one piece hot end. I am just starting with scad and feel that I am doing something stupid and making mistakes that a more experienced person would not make.

The modifications look good in scad and the slic3r viewer, but when I come to print I get bridging at a height of 4mm across a 40x40 mm hole and again 3mm from the top of the hole. Also, you can see from problem-pic2 that the vents all have bridging where it should be an empty space.

As I have said I am pretty sure that the problem lies with my understanding of scad ( or lack of skills) so I am attaching my scad file, perhaps one of you experts on scad could take a look and point me in the right direction.

looking forward to being educated
Paul

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appjaws - Core XYUV Duet Ethernet Duex5
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OpenSCAD version 2020.07
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I'm not sure what's caused that, but here are a few hints:

1. When using the difference operator to create a hole or cutout, always extend the shape you are removing beyond the face of the object you are removing it from. You can see this in Matt's original design, where he typically extends the shape he is removing 1mm beyond the face of the shape he is removing from. Otherwise you can be left with a very thin skin in the STL that won't always show up in the openscad view.

2. Before you export STL from openscad, always do a Compile & Render first. I've had strange results when I didn't.

3. After importing the STL into slic3r, use the slic3r View command to make sure it looks OK.

Edited 1 time(s). Last edit at 04/11/2014 08:04AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks David,
I have made sure that the cutouts do extend beyond the face, in fact I have not altered the main block from Matts original except to change the z variable to 20 from 15.1.
I also always action F6, otherwise you can not export a stl file.
Again it looks good in the slic3r viewer.
It's certainly strange and I'm sure will turn out to be a minor problem. Could it have something to do with the order of items in scad? Having said that, it does compile with no errors:-
Module cache size: 1 modules
Compiling design (CSG Tree generation)...
Rendering Polygon Mesh using CGAL...
PolySets in cache: 60
PolySet cache size in bytes: 153984
CGAL Polyhedrons in cache: 135
CGAL cache size in bytes: 6214232
Top level object is a 3D object:
Simple: yes
Valid: yes
Vertices: 773
Halfedges: 2450
Edges: 1225
Halffacets: 904
Facets: 452
Volumes: 2
Total rendering time: 0 hours, 0 minutes, 12 seconds
Rendering finished.

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appjaws - Core XYUV Duet Ethernet Duex5
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Dies slic3r think the STL is manifold, or does it auto-repair it?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hello David,

Sorry it has taken so long to reply.
slic3r says Manifold: yes - I'm not sure what Manifold actually means

I noticed a repair stl option in the file menu so I selected this and then selected the stl file for repair. It was repaired and saved as a .obj file.
Loaded this file into slic3r and by the side of Manifold was a yellow triangle with what looks like an exclamation mark in the centre followed by Auto-repaired (4 errors).

So do you think this item should print now and the problem resolved

Should auto repair happen automatically on the original stl file?

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appjaws - Core XYUV Duet Ethernet Duex5
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OpenSCAD version 2020.07
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appjaws, what I meant was: when you first load the STL file generated by openscad into slic3r, is there a message in the Info pane that the file was auto-repaired? If so, that is a sure sign that there is something wrong with the STL file.

I need to do a print to test some new firmware, so I'll try printing that file myself.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

No, it just said Manifold: yes
It will be interesting to see if it prints for you, thank you for taking the time.

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appjaws - Core XYUV Duet Ethernet Duex5
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OpenSCAD version 2020.07
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I'm printing this now, using firmware 057za-dc42 ...

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

It printed OK for me apart from some poor bridges.



I loaded the file into openscad 2013.06, did a compile/render, exported the STL, then sliced it using slic3r 1.0RC3 and my standard settings.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hello again David,
Thank you ever so much printing my problem item. I just knew that it must be something silly that I had done, so it appears that I have scil3r setting wrong. After all in the slic3r viewer the part looked good with no reported errors. It is strange though that I haven't had any problems printing other items that I have made/modified in openscad and then sliced with slic3r.

My version of slicr is 1.0.0rc3 and OpenSCAD version 2013.06 -- so same as yours. Below are my slic3r setting, could you compare them to yours please so I can identify which setting is causing the problems.

*********************This is my filament settings*************
# generated by Slic3r 1.0.0RC3 on Mon Apr 14 17:20:37 2014
bed_temperature = 65
bridge_fan_speed = 100
cooling = 1
disable_fan_first_layers = 3
extrusion_multiplier = 1
fan_always_on = 0
fan_below_layer_time = 60
filament_diameter = 1.75
first_layer_bed_temperature = 65
first_layer_temperature = 198
max_fan_speed = 100
min_fan_speed = 35
min_print_speed = 10
slowdown_below_layer_time = 15
temperature = 192

****************Print settings*****************
# generated by Slic3r 1.0.0RC3 on Mon Apr 14 15:01:06 2014
avoid_crossing_perimeters = 1
bottom_solid_layers = 3
bridge_acceleration = 0
bridge_flow_ratio = 1
bridge_speed = 60
brim_width = 0
complete_objects = 1
default_acceleration = 0
external_perimeter_speed = 70%
external_perimeters_first =
extra_perimeters = 1
extruder_clearance_height = 40
extruder_clearance_radius = 43
extrusion_width = 0
fill_angle = 45
fill_density = 0.45
fill_pattern = rectilinear
first_layer_acceleration = 0
first_layer_extrusion_width = 200%
first_layer_height = 150%
first_layer_speed = 25%
gap_fill_speed = 10
gcode_comments = 0
infill_acceleration = 0
infill_every_layers = 1
infill_extruder = 1
infill_extrusion_width = 0
infill_first = 0
infill_only_where_needed = 0
infill_speed = 50
layer_height = 0.25
min_skirt_length = 0
notes =
only_retract_when_crossing_perimeters = 1
ooze_prevention = 0
output_filename_format = [input_filename_base].gcode
overhangs = 1
perimeter_acceleration = 0
perimeter_extruder = 1
perimeter_extrusion_width = 0.7
perimeter_speed = 30
perimeters = 2
post_process =
raft_layers = 0
randomize_start = 0
resolution = 0
skirt_distance = 10
skirt_height = 2
skirts = 2
small_perimeter_speed = 60%
solid_fill_pattern = rectilinear
solid_infill_below_area = 70
solid_infill_every_layers = 0
solid_infill_extrusion_width = 0
solid_infill_speed = 70%
spiral_vase = 0
standby_temperature_delta = -5
start_perimeters_at_concave_points = 0
start_perimeters_at_non_overhang = 0
support_material = 0
support_material_angle = 0
support_material_enforce_layers = 0
support_material_extruder = 1
support_material_extrusion_width = 0
support_material_interface_extruder = 1
support_material_interface_layers = 0
support_material_interface_spacing = 0
support_material_pattern = rectilinear
support_material_spacing = 2.5
support_material_speed = 60
support_material_threshold = 0
thin_walls = 1
threads = 8
top_infill_extrusion_width = 0.8
top_solid_infill_speed = 50%
top_solid_layers = 4
travel_speed = 90


****************Printer settings*************
# generated by Slic3r 1.0.0RC3 on Mon Apr 14 15:01:06 2014
avoid_crossing_perimeters = 1
bottom_solid_layers = 3
bridge_acceleration = 0
bridge_flow_ratio = 1
bridge_speed = 60
brim_width = 0
complete_objects = 1
default_acceleration = 0
external_perimeter_speed = 70%
external_perimeters_first =
extra_perimeters = 1
extruder_clearance_height = 40
extruder_clearance_radius = 43
extrusion_width = 0
fill_angle = 45
fill_density = 0.45
fill_pattern = rectilinear
first_layer_acceleration = 0
first_layer_extrusion_width = 200%
first_layer_height = 150%
first_layer_speed = 25%
gap_fill_speed = 10
gcode_comments = 0
infill_acceleration = 0
infill_every_layers = 1
infill_extruder = 1
infill_extrusion_width = 0
infill_first = 0
infill_only_where_needed = 0
infill_speed = 50
layer_height = 0.25
min_skirt_length = 0
notes =
only_retract_when_crossing_perimeters = 1
ooze_prevention = 0
output_filename_format = [input_filename_base].gcode
overhangs = 1
perimeter_acceleration = 0
perimeter_extruder = 1
perimeter_extrusion_width = 0.7
perimeter_speed = 30
perimeters = 2
post_process =
raft_layers = 0
randomize_start = 0
resolution = 0
skirt_distance = 10
skirt_height = 2
skirts = 2
small_perimeter_speed = 60%
solid_fill_pattern = rectilinear
solid_infill_below_area = 70
solid_infill_every_layers = 0
solid_infill_extrusion_width = 0
solid_infill_speed = 70%
spiral_vase = 0
standby_temperature_delta = -5
start_perimeters_at_concave_points = 0
start_perimeters_at_non_overhang = 0
support_material = 0
support_material_angle = 0
support_material_enforce_layers = 0
support_material_extruder = 1
support_material_extrusion_width = 0
support_material_interface_extruder = 1
support_material_interface_layers = 0
support_material_interface_spacing = 0
support_material_pattern = rectilinear
support_material_spacing = 2.5
support_material_speed = 60
support_material_threshold = 0
thin_walls = 1
threads = 8
top_infill_extrusion_width = 0.8
top_solid_infill_speed = 50%
top_solid_layers = 4
travel_speed = 90

Much appreciate your support
Paul

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appjaws - Core XYUV Duet Ethernet Duex5
firmware 3.1.1 Web Interface 3.1.1
Ormerod 1-converted to laser engraver, Duet wifi
OpenSCAD version 2020.07
slic3r-1.3.0, Simplify3D 4.1.2, Cura-4.4.1

Attached photo shows modified Hot end with 3 vents. -- At last---

The file that printed on dc42's machine would not print on mine and kept trying to bridge/fill in large spaces. I still do not know what caused slic3r to do this, the only items of set up I have changed are some of the speed settings, I got so frustrated with this that I became confused (not hard to do) so am not sure which setting or settings were to blame.
It is also worthy of note that other parts printed just fine.

I am using RepRapFirmware-057zb-dc42.bin and 0.68 interface.
Earlier today I thought I would try the old version of slic3r - 0.9.10b but when I drop the part onto the Plater I get the following message:-
Warning: The input file contains a hole near edge 46.000000,79000000,13-45.757600,79.000000,13.000000(not manifold). You might want to repair it and retry, or to check the resulting G-code before printing anyway.
Anybody know what this means? and how would I identify and repair?

This leads me to another question. Now that I have created from scratch some items and modified some existing parts using OpenScad, I had a few issues after compiling and rendering with export as stl. I would get this message :- Object isn't a valid 2-manifold! Modify your design

Again I know that this is something to do with holding water, to make sure you have no holes in the design. My problem is then trying to identify where the problem is.

What do you do to identify potential problems in your design?

Well must test the new hot-end-3vents and see if that helps with bridging.

Thank you for all interest shown

Paul

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appjaws - Core XYUV Duet Ethernet Duex5
firmware 3.1.1 Web Interface 3.1.1
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OpenSCAD version 2020.07
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If the STL is "not manifold" It is usually because you have two objects that are touching along a single edge or point. Objects must either not touch at all, overlap or have touching faces rather than edges.

Look at this simple openscad example:

cube([10,10,10]);
translate ([10,10,0])
cube([10,10,10]);

It has two cubes that are touching only along their edges. This is not manifold and will therefore not convert. Always look at the line in OpenScad that says "simple". Your designs should always have this line report "simple: yes". You will see that my example reports "simple: no" because the cubes are touching along just their edge. Change the "translate" parameters in my example to anything else (e.g. "translate([9.99,9.99,0]) and the design will be OK. It will also be OK if the faces are touching e.g. "translate([10,0,0])"

Also make sure that all cutouts formed with the "difference()" command do not finish exactly at the face of an object.

e,g.

difference(){
cube([10,10,10]);
translate ([5,5,0])
cylinder(r=2,h=10,$fn=50);
}

is not a good idea (though it often works) because the cylinder ends are flush with the cube faces.

Rather extend the cutout beyond the faces

difference(){
cube([10,10,10]);
translate ([5,5,-.1])
cylinder(r=2,h=10.2,$fn=50);
}


Dave
(#106)

Edited 1 time(s). Last edit at 04/18/2014 07:14AM by dmould.

Thank you for that explanation Dave, the cutout(extension past the face) I have been applying and they are reasonably easy to find.
The problem I had was on a fairly complex part, how to identify when two objects are touching along a single edge or point.
My method so far is trial and error, highlighting each line at a time so it can be examined, removing the live and trying F6 again. This is so time consuming, there must be a better way of diagnosing and identifying problems.
I expect expensive cad programs have this built in.

Of course the best solution is to not make any mistakes in the first place.

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appjaws - Core XYUV Duet Ethernet Duex5
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When I had that problem, I did a binary chop to find the offending shapes. That is easier to achieve if you wrote your code with modules for each sub-part rather than in a single chunk, but can still be done however the code is written. I first commented out about half of the modules or objects in my design - if OpenScad reported "simple: yes" at least one of the problem shapes is in the commented-out lines, if not they are in the other lines. I then commented out half the objects in the problem half, and then half of that etc. until I identified one of the offending objects. It really didn't take long at all. In my case a cylindrical cut-out was grazing the edge of a cubic cut-out. It's not necessarily a mistake at all - there is nothing wrong with touching edges except that the STL format and slicing program doesn't like them.

It's not quite so easy of course if you have more than one problem, but you can still use a variation of the method. The "block comment" characters are a boon when commenting out large chunks (/* to start comment block, */ to end the block).

Dave
(#106)

Thank you Dave,
That procedure sound great and is basically what I have been trying to do, you are right it would be simpler is my items were broken down to modules. That's what I must do in future. now where did I see information about modules in OpenScad?

Paul

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appjaws - Core XYUV Duet Ethernet Duex5
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Well I am at a loss to explain what is happening to my modified hot end 3 vents part. This morning it printed OK but I had the length of the vents 3mm too long. So I shortened it in OpenScad just by altering a parameter. I did need to adjust a few more lines but the model compiled and rendered with no errors. In the slic3r viewer all looked good.
As you can see from the photo, attached, at a height of 15mm, with 5mm of upright walls to go, something decided that the main hole 42x42mm should be bridged.
This is the same issue I have been having all last week and when it printed properly this morning I thought the troubles were over.
How wrong can I be?

I have been flailing around in the dark, it is obvious that I need some help, so I am attaching my latest OpenScad and slic3r settings files in the hope that somebody will take a look and point me in the right direction.

Thank you for any response.

Paul

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appjaws - Core XYUV Duet Ethernet Duex5
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OpenSCAD version 2020.07
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Paul, you asked for my slic3r settings. Here they are. I haven't tried printing your latest model, but these are the ones I used to print your earlier model that was bridging when you printed it.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thank you David, that helped I think I might have found the problem.
Reprinting now

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appjaws - Core XYUV Duet Ethernet Duex5
firmware 3.1.1 Web Interface 3.1.1
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OpenSCAD version 2020.07
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If your print shows that you really have found the problem, please share the details with us!

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Of course, everybody will know!!!!

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appjaws - Core XYUV Duet Ethernet Duex5
firmware 3.1.1 Web Interface 3.1.1
Ormerod 1-converted to laser engraver, Duet wifi
OpenSCAD version 2020.07
slic3r-1.3.0, Simplify3D 4.1.2, Cura-4.4.1

Sad, sad, sad----It wasn't what I thought.

Having had a break for a day or so I looked at the g file in Pronterface and saw exactly where the print was going wrong. I altered my model to put an infill at the top of the vent slope, so now during print, the infill at the top of the vents stop instead of carrying on through and filling the hole.
I then checked again but this time my tie wrap cut-out was filled in. I could not see any reason for this so I changed the design to a tee. and am now printing the part.
I still have not identified why slic3r wants to fill in the large holes, especially when the viewer shows no problems and the holes clear.
Very strange, It will take somebody cleverer than me to solve this.
Than you all for your support
Pau

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appjaws - Core XYUV Duet Ethernet Duex5
firmware 3.1.1 Web Interface 3.1.1
Ormerod 1-converted to laser engraver, Duet wifi
OpenSCAD version 2020.07
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Can't help with scad Paul, but I did my own variation in sketchup, based on Matts part, with 3 vents. I have attached the stl in case you want to take a look.

Regards,

Les

Paul, have you tried slicing your original model using the slic3r settings files I posted yesterday?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

PS - slic3r 1.0 stable has now been released, so you could try upgrading to it if you are still using one of the RC versions.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

When I compared your settings with mine, I saw an option -Complete objects, I had 1 you had 0 so I jumped to the conclusion that that was the problem, slic3r was trying to complete the object. As you know this wasn't the problem, it was my model..
I will try and print the original with your settings but I just wanted to get this going and see if it will improve bridging.
I will also update slic3r, thank you.
I'll keep you informed.

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appjaws - Core XYUV Duet Ethernet Duex5
firmware 3.1.1 Web Interface 3.1.1
Ormerod 1-converted to laser engraver, Duet wifi
OpenSCAD version 2020.07
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Pointy - Did your 3 vent make a difference to bridging?

dc42 - I tried with your settings and it printed ok. I then changed your settings one at a time and checked in Pronterface for the fill in hole problem Each time I did this the print would have been ok. I then tried all of my settings and the print would have worked. It is almost as if this is random.

So I have given up now, updated to slic3r 1.1.0 experimental, just sliced my latest version of hot-end-3vents and all looks well. I am just about to print so fingers crossed.

I did notice in another thread that BigBlue was having problems with an internal platform being constructed when the viewer did not show it and it was not part of the design.

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appjaws - Core XYUV Duet Ethernet Duex5
firmware 3.1.1 Web Interface 3.1.1
Ormerod 1-converted to laser engraver, Duet wifi
OpenSCAD version 2020.07
slic3r-1.3.0, Simplify3D 4.1.2, Cura-4.4.1

Quote
appjaws1
Pointy - Did your 3 vent make a difference to bridging?

To be honest, I think the only bridges I have printed are the ones in my hotend and they came out ok, but they are only 21mm long. I have however replaced the fan with a much slower quieter one, which probably isn't pushing as much air either.

Regards,

Les

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