Resin tips


Here are some basic tips on common resins used in Ember, plus general resin tips.

General Tips

  • To maximize resin tray life, remove resins from trays when not printing. (The UV blockers in resins diffuse into the PDMS.)
  • If your parts print halfway, or if only the supports print, not enough light is reaching the resin.
  • If nothing prints at all, the problem could be not enough light or an improperly calibrated build head (see video).
  • To compensate (up to a point) for reduced UV transmission in a tray, increase exposure time, increase projector LED current. Eventually you’ll need to use a new tray.
  • The best way to be sure that your tray is letting enough light through is measure its irradiance with a radiometer. The second-best way is to print a test part.
  • Resin only cures in the absence of oxygen. Putting parts that are wet with uncured resin under a UV lamp will not cure the wet resin – unless there is no oxygen present, such as when nitrogen is pumped into a UV lamp box. Users have also tried curing in a glycerine bath with some success.
  • If resin drips onto your projector window and cures there, it can be easily removed with a sharp razor blade.
  • Isopropyl alcohol is great for cleaning parts, but parts will swell if soaked for more than 10-15 minutes

PR48 (Autodesk Standard Clear)

  • PR48 contains UV blockers that quickly diffuse into PDMS, rendering resin trays useless after 1-3 days if left in the tray continuously.
  • To extend resin tray life as much as possible, remove PR48 from trays when not printing.
  • Post-curing in a UV box filled with nitrogen (to displace oxygen) results in a clear, glossy surface.
  • Too much post-curing under UV can result in yellowing.

PR57C/M/Y/K/W (Autodesk Colored Prototyping Resins)

  • Contains much less UV blocker than PR48, so tray life is significantly longer.
  • Removing PR57 from trays when not in use will still extend tray life.
  • Slightly more brittle than PR48.
  • Does not yellow when post-cured.
  • Will sometimes display surface cracking when post-cured.

FormLabs Clear/Tough

  • Higher viscosity than PR48.
  • Use the default PR48 settings, but increase exposure time to 2.5-2.7 seconds and reduce separation velocity to 4 RPM
  • If you still get jamming, try turning up the motor voltage.
  • More info on settings here.

B9 Yellow/Cherry/Emerald investment casting resin

  • Works as a casting resin.
  • Diffuses UV blockers into PDMS, much like PR48, so make sure remove it from trays when not printing.
  • The default PR57 25-micron settings are a good starting point. Lots more info on settings here.

Print failure