Printing PVA support

[maxmk 0]

Hi everyone!

I am trying to print a complicated part with PVA as support.

Cura already does a great job at this with activated purge tower and

temperature difference.

There are only two things that annoy me:

The tower goes all the way to the last layer, meaning that I get a few hundred unnecessary extruder switches. It would be great if the support extruder would just cool down when all supports are finished.

Another important thing for PVA support would be a roof for the support. Just two layers on top of the support would make the surface of the print much nicer.

Is there any way to do this manually or will those features be in a future Cura release?

Thanks in advance!

 

[Daid 306]

Currently there is no real way to do this in Cura.

But do expect support for multi-extruders to improve a lot this year.

 

[drayson 75]

Hmmm....

Regarding the first suggestion you could try to slice the model 2 times - one with and one without support and exchange the upper part where no support is needed any more with the gcode from the slice without support... and add a line for cooldown the PVA extruder (M104?)...

Can you follow...? Don´t know if it well explaines what I have in mind... :-)

I don´t know if this could work but I remember a discussion regarding a plugin for change infill...

 

[Dim3nsioneer 557]

You mean the https://github.com/pmsimard/Cura/raw/SteamEngine/plugins/swapAtZ.pyplugin by http://umforum.ultimaker.com/index.php?/user/35529-pm-dude/... Everything in there except the M104... which can be realised by the https://github.com/Dim3nsioneer/Cura-Plugins/wiki/Tweak-At-Z-pluginplugin... (which is available since today in an all new version btw. )

 

[maxmk 0]

Thanks, that's a genius idea!

I just tried to do this manually using a text editor and it works.

I hope this is one of the first points on Daids list for dual extrusion.

https://drive.google.com/file/d/0B4WbDsFout-NV3EteUNyU1R2RU0/view?usp=sharing

 

[drayson 75]

Yes, that´s what I mean...

@ MaxMK, maybe worth trying with it... :smile:

Did a brief test - it´s working, just the order of generation of the files has to be considered

- first slice without support and second nozzle setting

- safe file

- slice same configuration with support and second nozzle setting

- past path to first file in the plugin

- define hight where no support is needed any more (in mm!!!)

- safe file again and open gcode-file in layer view to check :smile:

Maybe there is a chance to get a updated version of PM_dude with layer selection - I´ll ask him :smile:

 

[drayson 75]

B.t.w. - with this you could also get a solution for the second part of your request

Just generate the support as a seperate part, merge it in CURA dedicated to the second nozzle and get a top support layer as normally used for a part...

Then use swapAtZ to modify the gcode where no support is needed any more and end with tweakAtZ for cooldown...

Might work but needs a lot of more PVA than just support...

 

[maxmk 0]

Might work but needs a lot of more PVA than just support...

 

I thought about that, too, but for high quality prints one meter more or less does not make much of a difference.

Another problem would be to create those supports in CAD. That can be quite a lot of work.

 

[drayson 75]

That´s true - but depends on your CAD. As far as I know in SolidWorks there is an option to create molds so that´s maybe used to create a support structure too...

B.t.w. pm_dude replied that the swapAtZ has not been tested the second nozzle support (also I did just a brief basic test...)

 

[pm_dude 27]

Hello,

Joining in a little late (3 days of stacked new topics and replies ). Yes the layer number could be added. Also please check the resulting gcode afterward to make sure the swap of layer and the tweak at z interact well together. I had cases where the other plugin would get dismissed due to the swap.

There should be no real problem with the second nozzle but unlike the first nozzle, the material amount will not be adjusted to take the swap into account.