Dual Extrusion 13.03 - first test

[Daid 306]

Yes, it's something I want to add. As I think it would help.

But the dual-extrusion I machine I have access too is giving none-stop problems right now. So I haven't got around to make it and test it yet. There is also the Cura Beta which is causing some issues for people, which is currently a higher priority.

 

[snowygrouch 1]

Ok Daid,

well if you would benefit from any dual extrusion tests, you know where you can find me !

Happy to try things out.

C.

 

[Daid 306]

Right now I would benefit from someone finding the time to find out what is wrong with the spawn of satan machine that I'm trying to use for my tests. But that's not something you can do from your place.

It would be interesting to know how much retraction is needed in dual extrusion prints when you are swapping nozzles. Did you do any experiments with that? I've tried a few different amounts and I'm currently using 36mm because that's the whole length from tip of the nozzle to top of the brass. But I just did a few random tests without a proper conclusion.

 

[snowygrouch 1]

Hi Daid,

I have not tested that, but my opinion is that (esp. with bowdens), a wipe tower for both print

and support material (or print 1 and 2 colours) will be a 100% requirement. I dont think

any amount of clever tweaks will get the ooze away without a wipe facility of some sort.

C.

 

 

[greengecko 8]

Hi

Just an idea. If I understand correctly a wipe tower would be a structure that needs to be printed with the model i.e. It uses plasteic and moreover slows down the print. Wouldn't it be easier to have a structure like a post in a corner of the print bed which triggers a mechanical swip from something that is attached and retracted via a spring at the print head. This would relax te necessity of a wipe tower.

[snowygrouch 1]

Yes,

Something similar is used on some commercial printers I have seen....however, if the printhead is moving to the edge of the printbed anyway I dont see it being massively faster than a wipetower thats printed right next to the part.

Also and more critically the PVA goes "off" when left hot (stationary) inside the printhead.

Printing a little of it every layer might totally remove that problem (typical KS wipetower pic. below)

I dont know how important it is for "normal" PLA, although certainly before I got active cooling, leaving a nozzle hot and static was a recipe for a plug in about 10mins flat.

(note the pic is of "Destroyer2012" 's machine - not mine)

C.