Cura 14.01 and Dual Hotend Prints On Rostock MAX

[bill-havins 0]

Please accept my apologies if this has been covered before.

I have adapted my Rostock MAX for dual hotend printing. I am using a Rambo 1.1 running a variant of Repetier Firmware 0.83 (adapted for the Rostock MAX).

In Cura 14.01 I have discovered an interesting "quirk." As one might imagine, I set up my machine settings including the appropriate offset for my second hotend/extruder (T1).

When one sets up a printer with two hotends/extruders Cura automatically offers templates for start/end code. In the start code the Z height is brought to a certain level and then both extruders are "primed." The second extruder (T1) is primed before the first extruder (T0). This leaves the first extruder ready to print when the main body of the g-code executes.

Here's the "quirk." If you choose to print a "raft" under your print you would expect the raft to print using the extruder you designated for support material (in my case, T1 - my second extruder). The layers depicted in the GUI indicate that that is exactly what will happen. But that is not what happens when the print actually runs. T0 is used to print the raft.

Now, you might think you could simply go into the g-code and insert a few lines of code (three, actually) to cause T1 to print the raft. But that can't be done because of T1's offset - if the raft is printed with T1 the raft print will be "off" by the amount of T1's offset. Oops!

So, the moral of the story is, T0 will print the raft in spite of what you see in the GUI.

Here's another interesting "need." If one is printing with, say ABS, and using, say, HIPS for support material. The "unified" retraction settings in 14.01 may leave one filament "starved" for material. So far in my experience ABS has seemed to require a greater amount of retraction than HIPS. If you optimize the retraction settings for ABS the HIPS portion of the print will be "starved." So there is a need to strike a compromise that causes some problems.

I have tried 14.02_RC5 but it tends to want to hang up and freeze on my Windows 7 64-bit computer. So for now I am running Cura 14.01.

Thanks to Daid for all of his hard work! Despite the above I still prefer Cura to other slicers that are available.

Bill

 

[Daid 306]

Latest RC from http://software.ultimaker.com/Cura_closed_beta/%20should%20print%20the%20raft%20with%20the%20support%20material%20hotend.

(Freezes of the RC have been reported with outdated zone-alarm doing funky stuff)