What do I need to know to successfully use Taulman/Dow EVOLV3D™ USM Universal Support Material? Taulman3D advertises a soluble support material (EVOLV3D™ USM Universal Support Material) that handles temperatures appropriate for nylon and is completely safe to flush down the drain. There's very little about how to print with it successfully, however, or how to remove it after printing.

Other than the documented (wide) print temperature range (200-250&nbsp;&deg;C), what do I need to know?
Advice From Taulman

On emailing Taulman asking for advice (after getting some initial failed prints), they responded with the following:


  [...W]e use the following settings. Support:
  
  
  Flow 115&nbsp;%
  Infill = 8-10&nbsp;%
  2 full surfaces at 100&nbsp;%
  Support speed 50&nbsp;% of print speed.
  


What I've learned trying to apply that advice:


Turning the flow percentage up as advised is a good idea.
17&nbsp;mm/s is definitely much too fast for this material -- at that speed it's more likely to stick to the nozzle than to the base layer -- but at 8.5&nbsp;mm/s it prints well.
The advice to keep the infill percentage low is solid if you want to be able to mechanically remove any readily accessible sections. I've tried a print with 30&nbsp;% infill after trying to diagnose a failure (more on that below), and while the print came out well, the support infill couldn't be mechanically removed, and was also very slow to dissolve (see below).


On Support Removal

At Taulman's recommended 10&nbsp;%-or-below infill percentage, any accessible parts can be mechanically removed. At 30&nbsp;%, that's not really possible anymore -- though 5-10 minutes in boiling water might get the edges loosened up enough to let the bulk of the material be scooped away.

If you're just going to let it sit in tap water that isn't being circulated, expect that to take a long time, and to have several cycles of scraping out material that's turned to a gel to allow more to be exposed.

Using boiling water speeds the process substantially. If you're using USM with a nylon (or other material that's safe to bring to 100&nbsp;&deg;C), do that.

How's Its Adherence To Nylon?

Not as strong as its adherence to itself. If you print a ceiling of USM on top of support infill of nylon, it's possible for that ceiling to come away with the print head; thus, it reduces risk of failed prints to use USM for the infill as well.

Thus, the "2 full surfaces at 100&nbsp;%" advice given by Taulman above isn't (as I interpret it) just about ensuring that there's a successfully-printed support floor or ceiling; it's also about ensuring that there's enough surface area between the support floor and the nylon of the main print for them to adhere.