Printing with two different resins


We would like to make a part with two different resins layered, a clear bottom and a black top.
Since we don’t want to re-upload any files, we have been uploading the entire file, pausing it, changing the resin tray and resuming the process. Since the majority of the part is with the black resin, we have been using the default printing settings for the black resin, and we have been somewhat successful.
However, we would like to optimize this process.
We do understand that the two resins have different properties, so is there any way we could improve the process? What is the biggest difference in terms of settings for the clear and black resin?


Hi Nomori! Printing with two resins is fun! I have done it before and what I did is to give different settings to the first group of layers (clear) and default settings for the rest. There are tutorials out there on how to do this using a csv. file.
Good luck!


Here’s the tutorial Elisa mentioned for using a CSV file:


Can we add a pause at a predefined layer, raise the build head to the inspection height and wait, then continue on key press?

How did you prevent cross contamination of the resins?


I start always with the clear resin, pause the print and give it some time (1 or 2 minutes) so that most of the resin go back to the tray. Then, I clean with kitchen paper as much as I can the building head and the part surface. If you need to, you can even remove the head and work freely outside of the printer (but this is risky, you may lose calibration).
Then just change the tray for black resin, place back the head (if you removed it) and continue the print. I recommend to give the first 2 or 3 black layers with a longer exposure time, similar to a burn-in layer, or the second part may not attach to the first one.
I never cleaned with IPA the first part but it is an option if you have small gaps and you need it. Also, I would never print first in black and later in clear, you would end up with a clear tray full of black residue.


Is the Pause a command we can use in the CSV file or is this just a manual operation?


My guess is that it can’t be in a CSV, but @greener1 would know for sure. Pause can be sent via SSH, so you could rig up some kind of script that reads /var/log/syslog and sends echo pause > /tmp/CommandPipe when it reaches the desired layer number.


That’s right.


Hi @Elisa_Aznarte, @scott_chabineau, @OwenSmithyman and @greener1,
Thank you all so much for the information.
We would probably like to add the pause at a predefined layer number; where can I find information on sending commands through the SSH/writing scripts? I am completely new to sending any commands through a script, so it would be great to see some instructions and examples!


I too, would like to see this info.


@OwenSmithyman and @greener1,
I appreciate your help with this issue, and as commented above, I would appreciate it if you could provide us with some guidelines for sending the pause command using the SSH?
I was looking at the Ember user manual, and I understand that a pause command can be sent, but I still do not understand how it is done for a specific layer. What does the “/var/log/syslog” command do?


I discovered a better way to do it, using the info in this document, which shows the list of Ember web API commands. I don’t have the bandwidth to write a script for you, but here are the commands to use in a terminal, with the printer connected via USB. If you’re on Windows, you’ll need to download cURL (see here for info).

curl -d "command=GETSTATUS" -X POST
This will get the status of the printer, which includes the layer number. You’ll need to write a script to issue this command every few seconds, and to parse the output and get the layer number.

Once the layer number is the desired number, the script should issue this command:
curl -d "command=PAUSE" -X POST

The best scripting language to use for this would probably be Perl, or possibly Python. There are many great tutorials for both out there on the interwebs.