Rough Layer On Top Of Support Material

[andy-marsden 0]

I have recently started using an Ultimaker. I have had problems with the layer above the support material.

The layer is uneven and very untidy, you can see the individual strands of plastic. The part pictured below is an example of the problem.It is the handle of a fork hence why it could not be printed flat. A similar thing continues all the way down the fork however I am unable to show the rest due to IP.

i have had this problem on a lot of products I have been prototyping!

Thanks for your help in advance

!

!

 

[gr5 2,265]

Please update what country you live in for your profile settings. Also if you are going to post something - please follow it so you will see the answers as soon as they come in. Not a month later when you remember to go back and check (top right corner click "follow this topic").

There is no easy answer to this. Forks, spoons, knives are particularly challenging. I recommend printing the fork vertical with the tines pointing up. Use lots of brim at the bottom. Lower your XY acceleration from typical of 5000mm/sec/sec to maybe 1000mm/sec/sec to reduce shaking (you can do this after it has been printing for a while - in fact everyone should try this in TUNE menu just to experience the difference - consider lowering JERK from 20 to 5 also). It should work okay vertical. It should stick fine if you use heat and glue and the first layer presses in nicely flat.

Alternatively make some kind of curved mold/jig out of some material that can withstand 100C such as ceramic, wood, glass. Then print the fork flat and when it is done heat it in just-boiled hot water and do the final curvature of the fork on the mold/jig.

Or you can clean up the rough surface on the fork with wet sandpaper. Just put water on regular sand paper. But it's not as good as the other solutions.

 

[andy-marsden 0]

Thanks for your reply,

So is there no way to improve this surface between the support material and the outer layer?

I have tried slowing the print speed of the outer layer, also changing the heat of the nozzle so that the plastic is extruded at a lower temperature and less likely to droop, along with changing the overlap of the extrusion.

I thought that some of these may improve the quality of the layer.

Any other thoughts on this?

 

[smorgana 0]

 

Just to note: this is not an Ultimaker specific problem... The way I see it... In order to get a relatively smooth surface (tops and bottoms) that layer needs to be "squished" into the previous layer.. when you use a support layer, such as grids or lines, that is not possible, so you basically get the contour of the filament as it was extruded.

To get a smooth layer against a support, the top of the support would need to be flat, but that defeats the ability to remove the support after the model is done. In other words supports depend on bad contact with the model in order to be removable, and bad contact means rough surface.

I've read about dissolvable supports... should we ever get that plus dual extrusion, you'll probably start seeing improvement in surface quality against the supports

In the cases where I need supports, I carefully consider the model's orientation on the build platform. You have to make compromises between surface quality, detail, total plastic used, build time, adhesion.. and probably more -- that's what makes the game fun.

 

[jparks 0]

I realize this is an old thread, but I am having the same issue with the print above the support material. I have the dissolvable material, but I can't figure out how to make the last couple of support layers to be solid without making all of the support layers solid. Anyone have a solution?

[gr5 2,265]

Are you using Cura? What version? I think the feature is called "roof"? It should be enabled by default.

[jparks 0]

Are you using Cura?  What version?  I think the feature is called "roof"?  It should be enabled by default.

Using Cura 15.04.2 - I don't see "roof" settings anywhere. It does have Support settings, but they seem to be limited to Structure Type (Grid or Line); Overhang angle for support (in degrees); Fill amount (percentage); Distance X/Y (mm); and Distance Z (mm).

I also see Top/Bottom thickness, but this only applies to the part and not the support structure.

[ahoeben 2,010]

Afaik, that version of Cura simply does not have that feature

[jparks 0]

Is there a version that I can use which includes the "roof" option? I am using an Airwolf Axiom 20 dual printer.

[gr5 2,265]

The latest cura has this feature 2.* but you will have to configure it for the airwolf. If you google around the internet maybe someone already did this for you. If you aren't printing near the edges of your print bed (the hardest part is loading the shape of your build platform) then customizing cura 2.* to an airwolf might be doable for you.

Certainly there are customizations for other printers so you could look at what they did (what files they edited) to get that to work. That's much more informative then looking just at cura by itself.

If you do a nice thorough job you can then post your changes here in the forum and it will likely make it back into a future version of cura.

[jparks 0]

Thanks gr5. I have spent considerable time trying to get the printed part to come out with a nice smooth surface between the part and the support material with two different materials (ABS with Hydrofill; ABS with HIPS). The transition layers are now looking pretty good, but now I'm having issues with the rest of the piece (warping, oozing, curling, etc). I get one issue fixed and another develops. *sheesh* I have spent a bit too much time and I need to go back to printing both part and support with the same material just to get moving ahead again. I'll definitely come back to this issue and I'll post the solution when/if I get it. I appreciate your help.

Regards.