Disable retraction for support structures?

[CBX_Micha 0]

Is it somehow possible to switch off retraction for/within support structures?
With tree support in particular, after every movement, the structure is retracted in order to draw a support line right next to it. This not only takes an enormous amount of time, but also results in increased wear and tear.

I've tried and searched pretty much everything here, but I couldn't find an option for this. Retraction applies to either everything or nothing...

Am I missing something?

 

Edited June 10 by CBX_Micha

[Slashee_the_Cow 382]

34 minutes ago, CBX_Micha said:

Am I missing something?

Not that I know of. AFAIK the only way to disable retraction solely within supports would be to use a post-processing script (or a plugin, but a post-processing script is easier).

 

36 minutes ago, CBX_Micha said:

With tree support in particular, after every movement, the structure is retracted in order to draw a support line right next to it.

Make sure you don't have Travel > Retraction Minimum Travel set too low, depending on your definition of "right next to it".

 

39 minutes ago, CBX_Micha said:

This not only takes an enormous amount of time, but also results in increased wear and tear.

Depends on your material and extruder of course, but a retraction shouldn't take very long at all. And the filaments which require a large retraction (like TPU) you really want the retraction anyway because it's already going to be string city. You can control the wear and tear on the filament with Travel > Maximum Retraction Count and Minimum Extruding Distance Window to make sure it doesn't go back and forth too much within a short span of filament.

[CBX_Micha 0]

Thanx for the fast answer.

So I'm not into coding, so I have to wait if someone who know about catch the same wish and code a plugin or post-proc...

All other I have set to save time without hit the (visible) quality. I'm sure it can be better if a professional move the screws but the most I'm ok with...

To be sure we talk about the same stuff I have attached a snap and marked the points where a retraction occur at the tree support...
A single retraction don't cost much time but so many on the same layer, also not needed at support structures, cumulate much over the time...

Edited June 10 by CBX_Micha

[Slashee_the_Cow 382]

28 minutes ago, CBX_Micha said:

A single retraction don't cost much time but so many on the same layer, also not needed at support structures, cumulate much over the time...

Slow print > bad print. Making your supports string city makes them harder to remove cleanly (even when the strings are just between parts of the support) because there's just more stuff in the way of getting to everything. But I can see where you're coming form.

 

It's especially bad with something like TPU, where stringing is a fact of life, but because they're still a bit flexible after the print, you can't just cleanly cut a whole bunch off.

(Want to remove a bunch of strings from PLA? Get a sharp craft/hobby knife, warm up the blade by dunking it in hot water then just run it along the edge/face. Want to remove a bunch of strings from TPU? Sorry, so soft a knife won't actually cut things at the surface. You need a sharp serrated blade and then because the bits are so small they don't hit more than one of the teeth it's not really that much more effective. Works great for cutting into your TPU though. Whether or not you intend to.)

 

37 minutes ago, CBX_Micha said:

So I'm not into coding, so I have to wait if someone who know about catch the same wish and code a plugin or post-proc...

Same wish? No. Free time? Ample. I'll have a look at it later but I can't make any promises.

[CBX_Micha 0]

... hey, a look is more then I can await. It's not so important but maybe a nice feature ...

[GregValiant 1,330]

The setting "Connect Support Lines" can really cut down on the number of retractions albeit at the expense of using a little more material.  I generally don't use support infill with tree supports.  I figure the trunk is robust enough to not need any filler.  Another thing you can do is to increase the "Support Infill Layer Thickness" to 2X layer height.  The infill will go down every other layer.

Those same two techniques can be used with Infill as well.

 

There used to be a setting for "Limit support retractions" but it was interfering with a lot of other things and so it was removed as being too hard to work around within Cura's code.

[CBX_Micha 0]

Ty a lot!

I will try some of your hints the next print. I have some identical in the pipe, so I can directly compare the time change.

[Slashee_the_Cow 382]

So the only testing I have done is so "in theory" it's just looking at the gcode in a text editor (I've looked in Cura but its gcode visualiser doesn't seem to appreciate the distinction) but it does remove all the retraction move commands (G1 with no X or Y value, just E) within support and support interface sections:

(No, don't ask me why the rounding differs in a couple of places there - I 100% guarantee that's not my script)

 

To use it, in Cura go to Help > Show Configuration Folder, go to the scripts folder and drop the .py file from the zip file in there. Restart Cura and it should be in the post-processor list as "Disable Support Retraction".

 

(And please let me know how it goes, especially if you notice any bugs... at Slashee Industries, customer satisfaction is our #1 priority.)

DisableSupportRetractionV1.zip

[CBX_Micha 0]

Thank you very much for your time and effort about this. And sorry for late response. I'm used to receiving an email when I reply to a thread, so I only check in here sporadically...

[Slashee_the_Cow 382]

2 hours ago, CBX_Micha said:

And sorry for late response. I'm used to receiving an email when I reply to a thread, so I only check in here sporadically...

Better late than never 😃 I just hope it helps.