Slic3r PE 'Send to printer'?

  • I wonder if it would be possible to just do a pull request for Slic3r PE to take the Duet connectivity from the main Slic3r dev branch that already has it working.

  • It seems prusa hasn't merged that code from slic3r. I checked the source code of 1.39 and didn't find the changes in PE

  • @AlexLin:

    OK I found a solution. It is a bit of a hack where I use the ip address /url to determine whether to send it to an octopi or a duet
    my octopi has address octopi.local
    my duet has address hevo.local
    I needed to do this since the PE version doesn't have the member variables that the orginal slic3r has compiled in c++. And there is no host_type as in the code above. And I have no urge to compile it all ..
    it is a hack an I will need to change it for every new releae..however I'm so use with my octopi just to hit 'send to printer', that it is worth it for me.
    for windows you will need to change the file (1.39 as example)
    sub send_gcode at line 1459 to

    sub send_gcode {
        my ($self) = @_;
        my $ua = LWP::UserAgent->new;
        my $res;
         if($self->{config}->octoprint_host eq 'octopi.local'){
    		$res = $ua->post(
            "http://" . $self->{config}->octoprint_host . "/api/files/local",
            Content_Type => 'form-data',
            'X-Api-Key' => $self->{config}->octoprint_apikey,
            Content => [
                file => [ 
                    # On Windows, the path has to be encoded in local code page for perl to be able to open it.
                    # Remove the UTF-8 flag from the perl string, so the LWP::UserAgent can insert 
                    # the UTF-8 encoded string into the request as a byte stream.
                print => $self->{send_gcode_file_print} ? 1 : 0,
             # slurp the file we would send into a string - should be someplace to reference this but could not find it?
             local $/=undef;
             open (my $gch,Slic3r::encode_path($self->{send_gcode_file}));
             my $gcode=<$gch>;
             # get the time string            
             my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);
             my $t = sprintf("%4d-%02d-%02dT%02d:%02d:%02d",$year+1900,$mon+1,$mday,$hour,$min,$sec);
             my $req = HTTP::Request->new(POST => "http://" . $self->{config}->octoprint_host . "/rr_upload?name=0:/gcodes/" . basename(Slic3r::encode_path($self->{send_gcode_file})) . "&time=$t",);
             $req->content( $gcode );
             $res = $ua->request($req);
             if ($res->is_success) {
                 if ($self->{send_gcode_file_print}) {
                     $res = $ua->get(
                         "http://" . $self->{config}->octoprint_host . "/rr_gcode?gcode=M32%20" . basename(Slic3r::encode_path($self->{send_gcode_file})),
        if ($res->is_success) {
            $self->statusbar->SetStatusText("G-code file successfully uploaded to the OctoPrint server");
        } else {
            my $message = "Error while uploading to the OctoPrint server: " . $res->status_line;
            Slic3r::GUI::show_error($self, $message);

    Thanks, that worked for me on 1.38.5.

  • nice , somebody else can use it;-)

  • @Phaedrux:

    I wonder if it would be possible to just do a pull request for Slic3r PE to take the Duet connectivity from the main Slic3r dev branch that already has it working.

    It looks like it is this commit, it should be possible to pull it in and build your 'own' slic3r version, but I guess that these are not the only changes needed. 5fbb245b9790193b6924735fd985dc3cd2350ee6 and 13f121e3d952cca33b1ee5fdd73c12d85bf54d0e also mention the duet.

    Edit: As I said before, I doubt that this would get accepted 😕

  • @AlexLin:

    OK I found a solution. It is a bit of a hack where I use the ip address /url to determine whether to send it to an octopi or a duet

    Nice work, well done. (in lieu of a 'like' button for an individual post) 🙂

  • I don't think prusa will accept a pull request for this issue at the moment.
    On github i found the following open issue, seems they will do some refactoring.

    Today they committed a change which seems to be part of the refactoring.

  • We'll see if we get a response to the most recently opened issue on Github I'm not too hopeful that the Prusa version will ever add in support for the Duet. I ended up making a post processing script that uploads the gcode file. The script is basically just the perl code that slic3r usually uses to upload files.

    #!/usr/bin/perl -i
    use strict;
    use warnings;
    use LWP::UserAgent;
    use File::Slurp;
    use File::Basename;
    # Set up filepath and filename
    my $filepath = $ARGV[0];
    $filepath =~ tr|\\|/|;
    my $filename = basename($filepath);
    my $ua = LWP::UserAgent->new;
    my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);
    my $t = sprintf("%4d-%02d-%02dT%02d:%02d:%02d",$year+1900,$mon+1,$mday,$hour,$min,$sec);
    my $server_endpoint = "http://192.168.X.XX/rr_upload?name=gcodes/$filename&time=$t";
    my $req = HTTP::Request->new(POST => $server_endpoint);
    my $data_file = read_file( $filepath, { binmode => ':raw' } );
    my $resp = $ua->request($req);
    if ($resp->is_success) { 
        my $message = $resp->decoded_content;
        print "Received reply: $message\n";
    }else {  
        print "HTTP POST error code: ", $resp->code, "\n";
        print "HTTP POST error message: ", $resp->message, "\n";   

    You'll have to put the address of your Duet where the "XXX" are in the $server_endpoint var. I run all my post processing scripts from a windows bat file which looks sort of like this at the end:

    perl "C:\Program Files\Slic3r\" %1
    del /f %1 

    The bat file uploads the gcode file and then deletes it. The first pause allows me to close the command window to cancel the upload/delete command. The last pause allows me to verify the upload worked.

    This process definitely isn't perfect, but is easier than manually uploading files.

  • Hi,

    I've added the option for sending G-Codes to Duet and already created a pull request for it (
    Let's see if Prusa will overtake it into their repo.

    If someone is interested in testing it can be cloned from

    Best regards,

  • @mloidl Great work, I hope they take it for the next release.

  • @mloidl nice,well done!!

  • @mloidl thanks for the work! great to see it was accepted!

    If it's not too much trouble, do you think you could post a release already built with the commit?

  • @mordekain I have not yet tried to build a release for another pc than mine. I'll try to create a linux appimage for testing. I'm not able to provide a windows or mac executable.
    On the other hand i assume prusa will release another beta or release candiate soon (current beta was released 19 days ago)

  • New release is up!

    The new feature works wonderfully, thanks @mloidl !

  • As already mentioned by @Mordekain, the latest Slic3r PE Release 1.41.0 contains the duet upload functionality.
    Unfortunately the timestamps for uploaded files are not set correctly. This has been fixed and is already submitted to the master branch, so it will be part of the next bug fix release.

  • @mloidl great work. Can't wait to try it out. Thanks.

  • @mloidl thanks for your work in the Duet integration!

    I'm running my Duet behind a reverse proxy with HTTP Basic Auth to add a (thin) layer of security.
    Any chance you can add auth credentials to Slic3r? No need for new UI fields, a simple would be sufficient.

    I'm not sure if the Slic3r HTTP library already supports this - looks like a custom (bare-bones) implementation based on curl?

  • @resam
    Please have a look to

    If this is what you want it should be possible to implement, since the logic is already implemented for octoprint.

    Are you able to build Slic3r by your self? I could then push it to my branch and you could test it.

  • @mloidl good find!
    Actually I'm having problems with getting my HTTPS cert accepted, although I set the path to my self-signed crt file in PEM format.
    I guess this is the problem:
    (not sure how / where Slic3r is built, but apparently on macOS they don't support custom CA files?)

  • I installed this new release, but I can't seen any menu / button to upload the file to the Duet; how do I configure that?

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