Printing verry small functional parts

[looking4 2]

The Ultimaker 2 is a great machine and I finished prints with great quality. Now I want to print some verry small but functional parts. Don't know if I can wangle it with my Ultimaker 2?

First I want to explain my experience with printing a latchingtongue. Maybe some other users can learn of my failures. You can find the model on YouMagine: https://www.youmagine.com/designs/latchingtongue

I started with printing the tongue facing upwards and temprature settings for a normal sized object. Hox I expected and you can see on the left side of the picture it didn't work.

Then I went on changing filament to PLA (using Formfutura PLA black with standard printing tempratures between 210°C and 220°C) and printing four latchingtongue objects at one time with 205°C. As you can see in the middle of the image I was able to get much stringing.

In this case I decreased temprature to 200°C and increased retraction length to 5,00 mm and retraction speed to 35 mm/s. I additional deactivated the combine option an increased empty running speed to 250 mm/s. A bad idea causing following problems:

 

• Empty running speed is too high and tears of some small objects from buildplate.
  
• Disabeling combining option was a worse mistake. It intends Cura to do a retraction for every infillline. This leads in a clogged nozzle because the fillament was melted down at the feeder, so the feeder couldn't transport fillament any more.
  
• The other retraction settings are too high for Formfutura PLA fillament, which is toweled at feeder and leeds to underextrution.
  
• The object orientation wasn't suitable for printing the tounge, which should be used as a spring, because the small layers tend to break.
  

After reducing retraction settings i get the result on the right side of the picture.

Now I changed the orientation in Cura and added support material. But you shoudn't use support material along all the object! The support material is melted to strong the tounge even when i use 0,2 mm spacing between support material and the object. I couldn't break of support matirial without destroying the small tounge.

 

I changed orientation a second time and used less support metarial like some bridge pier. I printed four latchingtongues at one time with the following settings:

 

• layer hight: 0,05 mm (0,1 mm first layer)
  
• layer speed: 15 mm/s
  
• extruder temprature: 195°C (210°C first layer)
  
• fan speed: 100% starting at second layer
  
• shell thickness: 0,8 mm
  
• retraction length: 4,5 mm
  
• retraction speed: 30 mm/s
  
• combining option: on
  
• empty running speed: 175 mm/s
  

The result isn't bad at all, but the small pins with planned diameter of 1,6 mm at top and bottom wouldn't be fine enough. As you can see in the pictures the diameter wobbles verry much.

Here's an additional object. As you can see the smal parts at the top of the object aren't printed fine. I reduced the extruder temprature to 190°C when when printer reached the layer the object gets small. It leads to underextrution. Using a higher temprature causes stringing between pin and the thin wall. Removing these strings will break the pin (1,6 mm diameter).

I hope more experienced useres can help me with some additional hints!

Is it possible to print out such small objects on an Ultimaker 2 or have I got to buy a SLA printer like Formlabs Form 1+?

Special thanks to Robert for his link http://support.3dverkstan.se/article/30-getting-better-prints. According to his guidance I will try to decrease acceleration and increase layer hight to 0,1 mm. Maybe it will be better? I will post my results.

 

 

[nick-foley 5]

Maybe test out using a different slicer. Cura is best-in-class, but for printing small things, its refusal to print walls thinner than 2X the nozzle diameter (it only plots there-and-back paths) becomes a major limitation.

Also, try an even lower temperature? Printing tiny details is all about having perfect control of the pressure inside the nozzle, and keeping the temperature low can help with that.

 

[DidierKlein 729]

I think increasing the layer height would be a good idea.

 

I did some tests with small parts and i first tried like you with 60 microns layers, result was okay but not good.

 

Having bigger layers will prevent some melting.

 

Here's what i had with bigger layer (i think it was 100 microns)

 

 

[xeno 108]

The only way I could print these hand details, was to draw them connected in a frame, in a set of 6,

so the nozzle kept going in one go.

I did have to remove some material after printing, and some broke during material removal.

this is the smallest I ever printed, with a layer of 0.05mm

 

[looking4 2]

Here are the results of the german voting ... for printing small parts.

With a layer hight of 0,05mm, reducing extrudertemperature to 190°C or lower leads to underextrution. On such small parts the Ultimaker 2 (and I think all other FDM printers) isn't able to get the right pressure on the fillament for such short printing lines and frequent retractions.

For this reason I changed the layer hight back to 0,1mm. Now deviation of extruded material doesn't attract attention so much and the firmness of the small cylindrical pins is better. In addition I reduced the acceleration from 3000mm/s² to 2000mm/s² found in the machine settings on the Ultimaker 2. According to these settings I was able to reduce the extrudertemperature to 185°C.

Here are some pictures. As you can see there are still small wobbles at the side of the pins, but printing quality is much better. I also added pictures of the printouts in the printer, so you can see the models arn't fully machined.

I want to note that the printing quality of the small cylindrical pins was nearly perfect when oriented flat with small support and 0,05mm layer hight. I only had to change orientation because I needed more precession on the latchingtongues.

Here are some more pictures of the second object. Now it seems to be functional. I think I only have to fully machined the light strings between the long pin and the wall.

To see how the settings work on other objects I tested the Make:rook tower in original size. You can find the model on YouMagine: https://www.youmagine.com/designs/make-rook-2015-3d-printer-shoot-out-sla-test. The stairways are printed fine and the battlement at the top are very sharp. As you can see there are only some issues on the overhang at the lowest spiral. They differ depending on the side. Left side is better the right side. I'm using the original fan of the Ultimaker 2. It's a well known problem depending on dissimilar distances of fans to the nozzle. I'll try another fanduct ... to be continued.

 

[dtmille2 0]

. . . its refusal to print walls thinner than 2X the nozzle diameter (it only plots there-and-back paths) becomes a major limitation.

 

Is there any plans to add functionality to Cura to allow it to slice wall thinner than 2X the nozzle diameter (or maybe it's really 2X the perimeter width)? this is a limitation to Cura that forces me to use Slic3r in certain situations.

 

[nallath 1,117]

Concrete plans? No. We're working on support stuff and the new Cura codebase. We just don't have the resources to build everything we want (we are looking for new software engineers though...)