Cura 3.2.1 - Is Combing realy working?!

[amagro 3]

I'm trying to print a TPU bracelet, and avoid retractions is a must, so the Combing Mode should resolve this, but I'm not getting what Combing is supposed to do.
What could be wrong?

 

 

Tks

[Dim3nsioneer 558]

Cura doesn't like to make large detours while combing. A detour length setting as in S3D would be nice.

However you can maybe improve the situation by disabling the "avoid printed parts" option. But you probably will not get rid of all the cross travels.

Using the "optimize perimeter" option might also help.

[amagro 3]

Hi @Dim3nsioneer,

 

Thanks for your feedback, I already tried to disabling the "avoid printed parts", but this situation with the travel toolpaths maintains.
The "optimize perimeter" was also selected.

 

 

[gr5 2,268]

I'm guessing cura isn't smart enough to figure out it can follow those skinny walls.  

 

Better to make it so you never ever see stringing.  I can usually tune my machine so that this amount of travels wouldn't matter and would be invisible.  Try printing all speeds at the same speeds (speed changes can cause issues) and try printing at 25mm/sec and as cold as possible - maybe 190C.  See if that eliminates all strings.

[amagro 3]

All velocities are at 20mm/s, temperature is 225C, maybe I can go lower.

This are the results:

 

How can I get rid of this bloops?

[cjs 34]

I think you may be able to reduce travel moves and therefore strings by enabling the "Optimize wall printing order" option implemented by @smartavionics. 

[tinkergnome 927]

1 hour ago, gr5 said:

I can usually tune my machine so that this amount of travels wouldn't matter and would be invisible.

 

@gr5  - I assume you forgot the two preconditions: "TPU" and "no retractions"...

If not... teach us the secrets!

 

BTW: @amagro  "Ultimaker TPU 95A" or something else?

[amagro 3]

@tinkergnome Is Polyflex by Polymaker

[tinkergnome 927]

Does your printer have an extruder with bowden tube? In this case: IMHO a certain amount of stringing is unavoidable for flexible materials.

(For a direct extruder you could simple turn on retractions...)

 

You can fight against it (a bit) by printing as slow and cool as possible (but it needs some heat for a good layer bonding...).

And choose the speed for travel moves as high as possible on your printer.

 

 

[amagro 3]

I'm using a BEETHEFIRST_plus, the extruder have a direct drive, and normally I don't have problems extruding any material, but with TPU is always more tricky.

Cura could also be more TPU friendly.

 

Edited March 15, 2018 by amagro