Dual Extruder Prime Tower Issue

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greg50
Posts: 19
Joined: Sun Jul 12, 2015 8:29 am

Dual Extruder Prime Tower Issue

Post by greg50 » Sun Aug 11, 2019 7:44 pm

I'm printing using two extruders to get two colors. My second color does not appear until layer 16. The prime tower does not print anything for extruder 2 in the prime tower until it reaches layer 16. Then of course it spews extruders 2 filament into thin air.

Should it not print each layer for the prime tower in each and every layer even if the model does not use the extruder for that layer.

kcchen_00
Posts: 1701
Joined: Thu Feb 19, 2015 12:42 am

Re: Dual Extruder Prime Tower Issue

Post by kcchen_00 » Wed Aug 14, 2019 9:03 pm

The extruder will print to the prime tower when on the change of the toolhead. So once the Color1 is done for the layer, the Color2 will prime the nozzle (in case of ooze) by printing to the tower. Color2 will finish off the current layer, then continue printing its portion of the next layer. Color1 will then prime itself by printing to the tower and print its portion of the layer.

Proper dual color prints should have both colors on every layer (one color could be inside the object). It sounds like your object doesn't comply with this. If that's the case, you may want to adjust the gcode (through the slicer) to reduce the extruder temp that won't be printing. Keeping the extruder at temp without extruding filament could lead to a clog (carbonization of filament).

Can you upload the two STLs of your object?

greg50
Posts: 19
Joined: Sun Jul 12, 2015 8:29 am

Re: Dual Extruder Prime Tower Issue

Post by greg50 » Wed Aug 14, 2019 11:03 pm

"Proper dual color prints should have both colors on every layer"

So your openly admitting that cura lulzbot edition is not capable of printing this....
cone.jpg
cone.jpg (2.93 KiB) Viewed 79 times

because it's not a "Proper dual color print" and your answer to printing this is to just move along to another slicer?

Wow!!!!! If you can't get the programming right, change the rules. That's a huge cop out.
Last edited by greg50 on Thu Aug 15, 2019 12:26 am, edited 1 time in total.

greg50
Posts: 19
Joined: Sun Jul 12, 2015 8:29 am

Re: Dual Extruder Prime Tower Issue

Post by greg50 » Thu Aug 15, 2019 12:24 am

This is probably a moot point now but as requested here are the stl's for the model. This is actually part of a larger print/design but I cut it down to make it simpler. A previous version of this was printed by someone else on a prusa with the mmu option using prusa slic3r. I am including a pic of that print (which it aced by the way).
xpi.jpg
The "X-Contoller" is also printed in dual color and is just as white as the legend logo's but looks grayish in the picture because of shadowing.
Attachments
Legend.stl
(318.44 KiB) Downloaded 3 times
Base.stl
(428.79 KiB) Downloaded 3 times

b-morgan
Posts: 287
Joined: Fri Aug 11, 2017 8:53 am

Re: Dual Extruder Prime Tower Issue

Post by b-morgan » Thu Aug 15, 2019 9:05 am

kcchen_00 wrote:
Wed Aug 14, 2019 9:03 pm
Proper dual color prints should have both colors on every layer.
I'm not sure where this comes from but I don't believe it. Take a look at the 3DBenchy files for dual printing which I have sliced and printed multiple times with CuraLE (including 3.6.18).

The prime tower has something printed on every layer. When the second extruder is finally used, it prints on a prime tower built with the first extruder.

I also sliced the model posted in this thread with CuraLE 3.6.18 and the preview (in CuraLE and Craftware) looks correct to me.

b-morgan
Posts: 287
Joined: Fri Aug 11, 2017 8:53 am

Re: Dual Extruder Prime Tower Issue

Post by b-morgan » Thu Aug 15, 2019 9:11 am

greg50 wrote:
Sun Aug 11, 2019 7:44 pm
I'm printing using two extruders to get two colors. My second color does not appear until layer 16. The prime tower does not print anything for extruder 2 in the prime tower until it reaches layer 16. Then of course it spews extruders 2 filament into thin air.

Should it not print each layer for the prime tower in each and every layer even if the model does not use the extruder for that layer.
The prime tower should have have layers 1-15 printed with the first color so that the second color on layer 16 gets put on top of them. Something is wrong with the slicing if the second color is printing into thin air.

greg50
Posts: 19
Joined: Sun Jul 12, 2015 8:29 am

Re: Dual Extruder Prime Tower Issue

Post by greg50 » Thu Aug 15, 2019 5:02 pm

Guys
Something is wrong indeed. If the layers prime on top of each other they would eventually get taller than the print due both colors being on same layer and the tower height effectively doubling on that layer.

They definitely print as two walls on the prime tower and as far as i can remember, always have.

Load my two stl’s and merge. Pick materials that show up with different colors in preview. Then pull down to layer 1 and begin to go up.

That being said. I thought this forum was used or monitored by the actual developers? I was attempting to report a bug. If not can anyone tell me where bugs should be reported?

kcchen_00
Posts: 1701
Joined: Thu Feb 19, 2015 12:42 am

Re: Dual Extruder Prime Tower Issue

Post by kcchen_00 » Thu Aug 15, 2019 8:12 pm

greg50 wrote:
Wed Aug 14, 2019 11:03 pm
"Proper dual color prints should have both colors on every layer"

So your openly admitting that cura lulzbot edition is not capable of printing this....cone.jpg
because it's not a "Proper dual color print" and your answer to printing this is to just move along to another slicer?

Wow!!!!! If you can't get the programming right, change the rules. That's a huge cop out.
Okay. Maybe the "proper dual color prints should have both colors on every layer" is a blanket statement. My apologies.

I've printed that cone before and had no problems. Most likely didn't use Cura. But I'm sure with some tweaking of the dual extrusion profile you can do it with Cura.

I don't know where you're coming off that I said to switch slicers. I used S3D with my previous printer, so since it was paid for it continued on to my Taz5. Relax... not worth getting your panties wadded up. There are plenty of slicers out there. Cura is pretty good in my book, and, TBH, LE put a lot of effort into features.
b-morgan wrote:
Thu Aug 15, 2019 9:05 am

I'm not sure where this comes from but I don't believe it.
You're right, it was a bad blanket statement on my part about the "proper dual color prints should have both colors on every layer".
The prime tower has something printed on every layer. When the second extruder is finally used, it prints on a prime tower built with the first extruder.
Yes, I believe that's correct. Filament is deposited on the prime tower at the beginning of each layer.
Last edited by kcchen_00 on Thu Aug 15, 2019 8:16 pm, edited 1 time in total.

kcchen_00
Posts: 1701
Joined: Thu Feb 19, 2015 12:42 am

Re: Dual Extruder Prime Tower Issue

Post by kcchen_00 » Thu Aug 15, 2019 8:15 pm

Duplicate

kcchen_00
Posts: 1701
Joined: Thu Feb 19, 2015 12:42 am

Re: Dual Extruder Prime Tower Issue

Post by kcchen_00 » Thu Aug 15, 2019 8:25 pm

greg50 wrote:
Thu Aug 15, 2019 5:02 pm
Guys
Something is wrong indeed. If the layers prime on top of each other they would eventually get taller than the print due both colors being on same layer and the tower height effectively doubling on that layer.
From what I've seen, slicers are smart enough to schedule the extrusions so that only one color is deposited on the prime tower per layer. So ColorA starts Layer10, ColorB on the prime tower and finishes Layer10. ColorB then begins Layer11 (no prime tower), ColorA then prints a layer to the prime tower, and finishes Layer11. ColorA begins Layer12 (no prime tower)... etc.


Not sure how you formally report a bug with Cura... should be through the forums, but it seems like LB only spot checks.

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