loading

The light intensity (or irradiance) of the Ember printer varies from day to day for a number of reasons. Ultimately, this variation can lead to failure in the printing process. Too much light, and the printed part will stick to the window, and jam the printer. Too little and no polymer forms.

The easiest way to account for this change is to measure the light intensity of the printer, and then adjust the exposure time, so that the dose (total amount of light received) is the same from day to day. That is

Dose of light (mJ/cm2) = Light intensity (mW/cm2) x exposure time (s)

This Instructable will outline how to measure the light intensity with a G&R Labs 221 radiometer with a 420 nm probe. An ILT1400 radiometer and an SEL005 probe and an A#28762 filter would also work. However, the build arm of the printer needs to be removed beause of the size of the probe

Step 1: First We Clean

First the printer tray needs to be removed, drained, and carefully cleaned with a solvent (isopropanol preferably). Any resin left on the window will be transferred to the radiometer probe and gunk it up.

<p>Excellent information. I need to buy a light meter now. </p><p>A couple of questions:</p><p>How did you generate the curves? Did you measure the light value before each print and correlate it to a pass/fail of the final part? </p><p> I find the exposure time required can vary based on geometry. What type of part was used to validate the pass/fail?</p><p>Do you have these curves for other materials?</p>
<p>I am not sure what is going on. Please file a ticket here and Cappie will solve it.</p><p><a href="https://support.ember.autodesk.com/hc/en-us/requests/new">https://support.ember.autodesk.com/hc/en-us/reques...</a></p>
<p>Anyone experienced a total whitewash by the projector... At this point my projector is dialed to 11 and is curing everything everywhere. </p>
<p>Anyone experienced a total whitewash by the projector... At this point my projector is dialed to 11 and is curing everything everywhere. </p>
<p>Anyone experienced a total whitewash by the projector... At this point my projector is dialed to 11 and is curing everything everywhere. </p>
<p>Interesting read !</p><p>I have a question:</p><p>During your tests, did you find a deviation of light intensity across the print area? </p><p>I am placing a few copies of the same model, some grow, some fail. Could my build area have variable light intensity? </p><p>Some printers have a compensation mask for each printer to compensate for that. <br>Others have a build in radiometer so the user adjusts manual before each build.</p><p>How does Ember handle it?</p>
<p>There is some deviation across the build area, and we are in the process of developing a software correction method for it. However, this deviation is much smaller than the variation in the window transmission over time.</p>

About This Instructable

1,402views

10favorites

License:

More by bad-zima:Creating Printer Settings for SLA/DLP Printers  SLA/DLP Basics Using Open FL With the Form1+ - How to Set the Dose 
Add instructable to: