Dual extrusion how-to

[Eaglezsoar]

So, a new effector design - might shave off an inch in circumference...

I think that is what is needed, a new effector design.

[JolietDelta]

Hi!

I know there is a re-designed platform posted but I was wondering if anyone knew WHY the stock platform rotates slightly? I'd love to fix this minor but frustrating problem without replacing all my arms and completely rebuilding my end effector. I'm using http://www.thingiverse.com/thing:214536 and it is perfect near the center of the bed or moving orthogonally to the extruder separation axis, but I'm seeing the platform rotate slightly as it travels along the axis of separation. It's really killing my ability to print successfully even single-extruder. Tightening belts, re-leveling delta towers, checking all ujoints for free rotation and re-calibrating the bed radius has been done and only minor adjustments performed (with correspondingly minor results). So far my best bet has been to mis-level the extruders so the one I'm not using is out of the way just enough but I can't dual-extrude big objects like that!

I designed the mount you are referring to. And I had the same trouble with tilting/rotating. Resulting in damaged prints (one of both extruders kicked the printed parts off the bed every now an then).
It was really annoying.

After some hours of tweaking the software I came to the conclusion that it has to be a mechanical issue.
In my case, the spacíng between the parallel rods of the X-tower was +0.5 mm at the effector, compared to what I meassured at the cheapskates.

The cure came in form of the TL rods. After installing and carefully alinging them, all tilting was gone.
I can now print across the whole heated bed with one or both extruders.

Delta printers tend to act like a Diva when it comes to mechanical alignments. And they turn out to be a Diva with PMS when running with two extruders. :-}

No, the orange ball on the right is no multi-color print. :-)

~Jens

[geneb]

Hi!

Delta printers tend to act like a Diva when it comes to mechanical alignments. And they turn out to be a Diva with PMS when running with two extruders. :-}
~Jens

I think this is THE most accurate statement ever made about deltas.

g.

[fehknt]

After some hours of tweaking the software I came to the conclusion that it has to be a mechanical issue.
In my case, the spacíng between the parallel rods of the X-tower was +0.5 mm at the effector, compared to what I meassured at the cheapskates.

The cure came in form of the TL rods. After installing and carefully alinging them, all tilting was gone.
I can now print across the whole heated bed with one or both extruders.

Yeah I came to the same conclusion but hadn't figured out why yet. I'll have to do some careful measuring and see if I can't shim 'em or something. I was thinking about getting the TL rods but I'd rather try to fix it with near-stock parts than throw money at the problem even if I'm sure that'll help just because that's how I am. I just finished another set of 3dr parts for a friend so the printer is free to make adjustments that might break printing again and I'll report back here if I succeed given your hints (thanks!).

[eroderz]

Hi all. This thread was incredibly helpful getting my dual extruder setup and thank you to everyone for the insight.

I'm curious why both extruders heat up even if it is a single extruder print? Is there a setting in the firmware or EEPROM that I'm missing? Seems like whenever i turn on one, the other automatically comes on. and the second extruder temperature control doesn't seem quite right to begin with... Help would be appreciated!

[geneb]

If you haven't modified the firmware as it comes from SeeMeCNC, HEAT 1 will come on when you heat the first hot end. This was done in order to turn on the PEEK fan automatically. If you're using dual-extruders, you'll need to make changes to the firmware.

g.

[eroderz]

I have modified the firmware per the original post of this thread. But did i miss somthing that would cause this? what exactly would i be looking for?

[eroderz]

So I havent been able to figure this out still... Seems my second extruder is tied to the first one and does not run independently. As you can see in the picture, the second extruder should be set to 0* but its not. It increases in temperature when the first one does. Can anyone point me where in the firmware this needs to change?

PLEASE HELP!!!

[Polygonhell]

I think by default the SeeMeCNC firmware maps the second extruder output to drive the peek fan, so when you turn on the first extruder the second one will also be turned on unless you've reconfigured the firmware.
The fix involves changes in pins.h and configuration.h, and it's probably covered somewhere in the thread.