m1sterd
Posts: 5
Joined: Thu Sep 03, 2015 7:58 am

Single extruder with multiple processes to change speed

Wed May 25, 2016 10:28 am

Hi All,

My first post, I have been using Simplify 3D for a little while now but have hit a particular task that I wan't to achieve in Simplify3D but don't know if its possible exactly as I required.

What I am after doing is being able to adjust the print speed based on the height of the print, the reason being that the bottom of the print is a fairly basic shape but then the top half of the print contains some fine detail (the actual print is a Hot Air Balloon basket where the basket prints easily at 50mm/s but the ropes that attach it to the balloon are fairly detailed and thin, therefore they need to print at about 30mm/s.

I have partially achieved what I want by having 2 processes defined as below:

Basket:

Layer -> Top Solid Layers = 3
Layer -> Bottom Solid Layers = 3
Layer -> Outline Perimeter Shells = 3
Advanced -> Stop printing at height = 18mm
Other -> Default Printing Speed = 50mm/s

Ropes:

Layer -> Top Solid Layers = 3
Layer -> Bottom Solid Layers = 0 (to stop an additional solid layer being put in when the ropes section starts)
Layer -> Outline Perimeter Shells = 5
Advanced -> Start printing at height = 18mm
Other -> Default Printing Speed = 50mm/s

My question, is there anything that can be done in S3D to prevent the the solid layer being created from the Basket process having a Top Solid Layers set to 3 as this is required for the inner basket floor?

CompoundCarl
Posts: 2005
Joined: Wed Aug 05, 2015 7:23 am

Re: Single extruder with multiple processes to change speed

Thu May 26, 2016 7:13 am

If you have top solid layers set to a value > 1, then it's going to create a top solid layer. No other way around that. You could create more processes if there's a section where you don't want any top solid layers, but otherwise, that's what it's going to do.

That being said, I've actually found that having a nice big solid layer between processes actually helps them bond together better

m1sterd
Posts: 5
Joined: Thu Sep 03, 2015 7:58 am

Re: Single extruder with multiple processes to change speed

Thu May 26, 2016 8:12 am

The problem I find is that sometimes a solid layer contracts differently to a non solid layer, so there can be a visible difference to the object on process changes because of this.

I wanted to see if I had missed a trick or setting within Simplify3D and if I hadn't then I was going to raise a feature request, which I guess would be something along the lines of, being able to link processes with the purpose of a continual print where only things such as temperature, fan, speed would change such that there would be no reason to require having solid top/bottom faces between processes.

gwcrook
Posts: 6
Joined: Mon May 23, 2016 10:05 am

Re: Single extruder with multiple processes to change speed

Thu May 26, 2016 3:46 pm

Set the top layers = 0

Rebekah_harper
Posts: 263
Joined: Wed Jan 21, 2015 10:25 am

Re: Single extruder with multiple processes to change speed

Thu May 26, 2016 6:33 pm

Hiya,

with multiple process it's pretty straight forward.

The minimum you need to do is have the process that covers the solid layers set with solid top layers to 3. same for bottom layers in the case of over hangs.

it's the only way.

easiest way is really to have all processes to have the solid layers the same. but only you know what you want to achieve

use the sectional view to establish the stop and start heights.

hope this helps

Becky

spinorkit
Posts: 3
Joined: Tue May 30, 2017 7:57 am

Re: Single extruder with multiple processes to change speed

Tue May 30, 2017 8:08 am

I find it quite limiting that you have to set the top and bottom layers to 0 if you don't want extra solid layers inserted into a print just because you want different printing properties as a function of height.
Setting the top and bottom layers to 0 is not feasible in the middle parts of many prints if you want complex shapes to print correctly and having solid layers inserted just because of a process changes is undesirable in many cases (e.g. changes the surface finish and adds weight).

To my way of thinking, it is a bug that a process change introduces a solid layer that is not in the original model (stl).

I realize it may not be possible to "fix" this "bug" without breaking user's existing processes, but it would be great to a check box to turn off this behavior.
E.g. a "Suppress solid layer generation at process transitions" check box in the advanced tab.

Thanks,
Kit

Rebekah_harper
Posts: 263
Joined: Wed Jan 21, 2015 10:25 am

Re: Single extruder with multiple processes to change speed

Sun Jun 04, 2017 4:47 am

Hiya,

a number of settings are regarded as part of a complete process.

I think what you are asking for is a new feature that assimilates multiple processes in a single over arching process.

the top and bottom are such settings. taking the process separately they are complete processes which you are stopping short and there for treats those printed parts as individual parts.

I don't think it's a bug just the way it was intentionally set up. setting top layer to 0 on the first process and bottom layer to 0 on the following process is reasonable.

you'll find that if they had it as you ask then someone would ask the same question as you just did but the other way around.

but I understand you frustration and have had similar but I just made sure that the settings married up such as infill pattern and density etc...

Bex

spinorkit
Posts: 3
Joined: Tue May 30, 2017 7:57 am

Re: Single extruder with multiple processes to change speed

Sun Jun 04, 2017 6:10 am

Hi Bex,
Many thanks for your reply.
The most common thing I want to do is increase the number of perimeters, or the extrusion width, or both, for a part of a print to increase strength in regions of high stress without adding too much weight.

However, I find setting the top layer to 0 on the first process and bottom layer to 0 on the following process can result in incorrectly printed parts for some shapes.

I attach an image of a typical scenario where I would like to use multiple processes.
This wing section is prone to fracturing at the stress point where the flap cutout starts, towards the bottom right in the image. I would like to be able to reinforce the wing section for a few mm around that height by switching from 1 perimeter to 2.
Unfortunately, setting the top layers to 0 on the first process (1 perimeter process) results in the servo cutout not having a roof, while setting the top layers to zero on the second (2 perimeter process) results in the trailing edge having no roof where it extends beyond the flap cutout.
So I have to choose between having these openings or having heavy solid infill right across the profile of the wing at the process boundaries.

Currently the only way I can see of achieving what I need is to leave the top and bottom layers non-zero and write a program to parse the g-code output and remove the unwanted solid infill layers, which is a pain.

Using multiple process to vary the properties of a print as a function of height is a powerful feature of S3D, but without an option to suppress unwanted solid infill layers at process transitions, it is unusable for some applications.
Multi-processWingsection.png

Kind regards,
Kit

Rebekah_harper
Posts: 263
Joined: Wed Jan 21, 2015 10:25 am

Re: Single extruder with multiple processes to change speed

Sun Jun 04, 2017 10:31 am

I see your problem.

a wing needs to be light as possible.

the only way I can think of resolving your problem is go back to the design.

what do you use to do the CAD.

What I would do is design the reinforcements as seperate solids. also the solid layers you want to maintain.

then save each of the solids seperately and load in S3D without auto arrange.

in Inventor I could explain this but anything else I wouldn't be sure.

in inventor when you do a save as (stl) it keeps it's 3d dimensional location and there for should appear where you designed it but you'd have to ensure that other solids in the CAD are invisible. then you can apply any process to each solid and they would blend during slicing

spinorkit
Posts: 3
Joined: Tue May 30, 2017 7:57 am

Re: Single extruder with multiple processes to change speed

Mon Jun 05, 2017 6:35 am

Thank you for this suggestion, I appreciate it.

I use OpenSCAD mostly and I could definitely do what you suggest.

For me however, it is less work long term to write a program to detect the unwanted solid layers at the process transitions in the g-code and remove them, especially since S3D generates well commented g-code.

It just means I can't simply put the S3D factory files up on e.g. thingiverse.

Thanks again,
Kit

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