Partial printing => reduce stringing, travel time, retractions

[Dampa 0]

Hello all,

 

I'm struggling quite a lot with stringing, adjusting retractions, coasting and others. 

 

I'm wondering if there is a setting in Cura for next purpose. This is a standard stringing test model:

 

 

In order to reduce travel time and stringing chances, is there a way (without modifying code manually) to partial print layers? Let me explain it better. After printing base, is there a way to print, for example...

• 10 mm for left tower, from Z 10.00 to Z 20.00
• then move to print right tower, from Z10.00 to Z 20.00
• return to left tower and print from Z 20.00 to Z 30.00
• and so on?

This will dramatically reduce travel time, retractions and stringings.

 

I'm pretty new on 3D printing world, so please, don't be too hard with me if this is a newbie question : ).

 

Thank you!!!

 

[gr5 2,229]

2 hours ago, Dampa said:

 

I'm struggling quite a lot with stringing, adjusting retractions, coasting and others. 

 

 

Which other's?  You don't have to answer that.  Speed helps the most.  Printing speed.  If you print at half speed there will be half as much pressure in the nozzle when printing and you are much less likely to leak.  But the speed of the travel should be as fast as possible (Ultimaker printers can usually go to 300mm/sec just fine for travel speed)

 

Also internal nozzle shape - for a 0.4mm nozzle, the longer that 0.4mm channel is, the less likely it will leak.

 

Material makes a big difference.  I find that white filaments string much more.

 

For retraction distance you want just enough to relieve pressure without actually allowing any air into the nozzle which causes even more stringing.

 

Keep in mind that I categorize stringing into two types.  The bad stringing look like thin horizontal threads.  The good stringing is when the threads are so thin you can't really see them but you get these tiny, curved/wavy vertical towers that tend to start at both ends and move away from the parts.  These extra thin strings aren't really much of a problem is they are so easy to remove.  2 seconds of work with fingers can remove hundreds at a time.  A little heat from a flame can also make most of them seemingly vanish (in actuality they shrink).

 

[gr5 2,229]

Your idea about printing one island for many layers and then going back down and printing the next island...

 

I've thought about that before.  For two well separated towers of course it would work fine.  But most things you print may have dozens of regions/islands and some may be very close together.  So the printer would need to know the shape of the bottom cm of the entire print head including fans, shrouds, heater blocks, etc.   And it would have to do lots of 3D checking to make sure there was no collision with parts of the print head with each island to print.  This calculation is done for 5 and 6 axis printing which is rare in 3d printing - mostly just subtractive manufacturing (milling machines).  The software/math for this is much harder and would make the slicer much slower but it would be great if Cura could do it.  While they are at it please make Cura capable of 5 axis printing!

 

Right now I think most people do 5 axis build paths using CAD tools like autocad.  I don't think there is a single 5 axis slicer out there.

 

I keep mentioning 5 axis printing because the math and planning is very similar to what you want.  So if you have the software to do one, you should be able to adapt it for the other.