SOLVED Cura change nozzle route for stronger mechanical resistance

[Youn 1]

Hello everyone,

 

With Cura, do you know if it is possible to change the nozzle route that is automatically generated ?

I am printing gears and I would like them to have more mechanical resistance, specifically between the teeth and the main body. By default, for each layer, the teeth are printed first and then the body (the cylinder part of the gear). Here's a picture of the preview :

 

We can see that the teeth are printed separately and it make the thing more breakable.

 

What I would like is to print them as one and unique body. I mean that I would like the nozzle to follow a unique red line that is the real outline of my component, as visible in the picture bellow (and no two different red lines as it currently is).

 

 

Do you know if it is possible to do such a thing with Cura ? Or if not, can you suggest me a software to do this ?

 

Thank you,

Youn

[gr5 2,172]

It's an issue with your model - not cura.  Your model is specifically defining the teeth as separate parts with a wall between.

 

Go back to CAD and try to merge the teeth into the rest of the part.

 

What CAD are you using?

[gr5 2,172]

There are also lots of free tools out there that might be able to fix this if this isn't your model.  I've never had to fix this particular problem but I'm guessing that meshmixer and meshlab both can probably fix this issue.

[Youn 1]

Thanks for your answer @gr5. The CAD I use is CATIA, I fist created the cylinder and then added the teeth but they are all merged together, there is no space between.

I will try to create the gear in a different way to see if there is a difference... So you think that Cura can know how things were made even after having all merged and exported into an STL file ?

 

Thanks I'll have a look into meshlab and meshmixer to see if it can fix this.

 

 

[gr5 2,172]

The red lines in Cura are always touching "walls" in CAD.  So yes there is still a wall there even though merged.  The merge didn't work or it doesn't work the way you think it does.  Maybe if you move the gears towards the cylinder 0.2mm and then merge again?  I don't know CATIA at all.

 

STL file contains just a list of unordered triangles.  Any two consecutive triangles can be far apart in physical space.  Anyway cura intersects a layer height with all those 3d triangles which gives you a set of lines in 2d space and then tries to figure out which lines go with which and makes loops.  Each loop is an "island" to print with a red line outer and then green shell and then yellow infill. It's tricky when you have two walls on top of each other like you do but cura figured it out correctly.

 

There's no way cura would put that red wall there unless there were triangles there.   So CATIA didn't quite merge the teeth in properly.

[Youn 1]

Alright I  will try to change thinks in CATIA in order to improve the merging...

 

Thanks for your answers,

Youn

[Youn 1]

So, to conclude this topic, I improved the merging by adding a new part at the exact place where the walls are. It makes things look realy ugly in CATIA but when I export the whole thing in stl and open it with Cura I have no issue anymore. It works fine ^^

 

Here's a picture of the new preview :

 

 

Thanks for your help !

[geert_2 557]

Catia, isn't that from the Dassault company? If yes, I think it might use the same engine as DesignSpark Mechanical (but then at full power, not feature-limited like the freeware DSM)?

 

I rarely have this sort of problems in DesignSpark Mechanical. But what occasionally happens is that things do not want to merge (or round, chamfer, cut, extend, whatever,...) if the edges do *exactly* fall together. If they overlap 0.01mm or so, this is not a problem. It is the "just touching" that is the problem. I have also seen this in other software, and in computer games as well: then you get flickering or zebra-patterns when both surfaces "fight" to be displayed.

 

Most of the time all those math operations just work fine in DSM, but if not, a solution is: make a small gap if you do not want (automatic/undesired) merging, or make a small overlap if you do want merging.

 

In DesignSpark Mechanical, you can give each object a different color. If they do merge during editing, on purpose or by accident, you will notice it because they all get the same color suddenly. This is a visual check, sort of. You can also see in the model tree if it is one object, or lots of objects.