Dual Extrusion Queries

[aperturist 0]

When dual extruding with dissolvable support material, is there a noticeable change in quality where the support structure was touching the print as compared to the parts where there was no support?

 

[nudelmannrichter 14]

very interesting, that nearly no replies are coming if one asks for special things bout UM2 double extruder. Ok I see, nobody is running one cause commercial versions still don't exist. I wonder if a tinkerer got something to run yet.... UM staff is telling that there is some progress and they plan to release something in 1stQ15. We hope the best....

 

[solid-print-3d 30]

It's such a sore spot with me, the whole dual extruder promise that was broken...twice!, that I wince at new dual extruder posts

 

[lrodriguez 32]

Patience is a virtue.

 

[ultiarjan 1,223]

Nobody likes waiting. But i prefer it over buying something that does not work... I say let them thorowly test... we can imagine what would happen with the um support desk otherwise....

[DidierKlein 729]

I have the same feeling, having seen some dual extrusion printers in action like the makerbot replicator 2x and seeing the result convinced me that it's better to wait for something that actually works flawlessly instead of having it quicker and work partially.

 

[Daid 306]

Soluble support material. Currently there are 2 real options that people are trying to use:

1) PVA

2) HIPS

Let me talk about HIPS first. First of, it's a styrene. Printing it gives off styrene gas during printing. Wikipedia can fill you on in the details of that: http://en.wikipedia.org/wiki/Styrene#Health_effects

Limonene needs to be used to disolve HIPS after printing. Which is a biological turpentine. Nasty stuff that needs special storage and special handling.

So. HIPS? Not really something we to do as Ultimaker, as we like our customers healthy.

PVA. Great on paper. As it dissolves in water. No nasty chemicals. Prints nice. Sticks well to PLA.

However. 2 problems.

Problem 1 "Crosslinking". This is the effect where PVA turns into carbon chains at temperatures. PVA seems to degrade and the older it is, the easier it crosslinks into carbon, blocking your nozzle. Pretty much requiring you to drill out the nozzle or buy a new one. Pretty annoying, as we haven't found the parameters yet which cause this. Rolls that print fine the first day, cause problems the next day. Right now, it's pretty much "once you get it out of the bag, you have 12 hours, after that it's danger material".

Problem 2. This stuff is soft at low temperatures. 35C it's soft. With the feeder wheel reaching 35-40C during normal operation, the PVA grinds very easy on retractions.

Bonus solution:

PLA does get soft at 100C. So if we would have a 2nd material that is still 100% stiff at 100C you could use PLA as support and the other material as build material. This is just an idea that we haven't tested yet.

 

[DidierKlein 729]

Interesting thanks for the information Daid.

So basically before even wanting to have dual extrusion (soluble supports is the only real utility for me), we have to wait for someone to develop a reliable and usable soluble material... Colorfabb maybe? :mrgreen: Or is Ultimaker also doing research on soluble materials?

 

[Daid 306]

Or is Ultimaker also doing research on soluble materials?

 

Where did you think the above information came from? Yes. We're looking into this. It's the main use for dual-extrusion right now. But we haven't solved the problem. (We are working with 3th parties, but sharing who those are isn't my place to do so)

Another use for dual-extrusion could be mixing 2 different materials in 1 print. Flexable materials could be interesting. But what I really hope for (but haven't seen yet) is a properly conducting filament. Not the 10kOhm/cm material that you can get right now. As a well conducting material would make 3D circuits possible. The material available right now can only be used for touch-sensing goals.

 

[3poro 9]

I think it will take quite some time before we'll see "conductive enough" filaments - unfortunately. Until then we'll have to stick to copper paint (http://umforum.ultimaker.com/index.php?/topic/3803-ultimaker-2-dual-extrusion/?p=73337). Especially under-extrusion problems and conductive filament don't really play well together.

How about using polycarbonate, PLA and a pressure cooker? http://en.wikipedia.org/wiki/Pressure_cooking

 

[Dim3nsioneer 557]

Soluble support material. Currently there are 2 real options that people are trying to use:

1) PVA

 

Are you allowed to tell with which parameters you printed the PVA?

 

[Daid 306]

Are you allowed to tell with which parameters you printed the PVA?

 

Single extrusion. UM2. Tried various temperatures, depending on the type of PVA (we got different possible suppliers, which need different settings). I didn't do most of the tests, so I do not know the exact details, but I know various different settings where tried. These where not simple one off tests, quite extensive testing has been done, and no solution for the crosslinking problem has been found by varying the settings.

 

[Dim3nsioneer 557]

T0=170°C?, Tbed=60°C? That's about it, isn't it?

 

[Daid 306]

T0=170°C?, Tbed=60°C? That's about it, isn't it?

If that is what the supplier recommends, most likely, yes. PVA is tricky material, and I would regard it as highly experimental if you have some. So you will have to play with it to find the proper settings. Start with what the supplier recommends and go from there. But I cannot say "if you use settings X it will print nice"