Missing one ball but should still make everyone happy

[robyneil @robyneil My Robox is a Blue Commercial Version]

Here’s my attempt on the “impossible” 3D print:

http://www.thingiverse.com/thing:51806

This is happiness. Good job CEL! This is true even when I found out that Cura sliced with 1 missing ball bearing near the axle pivot of outer ring (see attached STL and gcode preview). Have a nice week everyone.

[Overview]
Model was first imported into Rhino3D to convert model and export as *.obj NURBs
(probably optional but wanted to solidify model even more). Then I imported the
model in MeshMixer to add overhang support structures.

[MeshMixer setting changes from default]
Y-Offset: 1.5mm
Density: 70
Base Diameter: 13mm
Convert to Solid: yes

[AutoMaker 1.01.01]
Slicer: Cura

Material: ABS Chroma Green
Scale: 100%
Choose quality: Normal
Print support material: Off
Brim (permiters): 2
Fill density (%): 99 (warning: Get a good table. This will make your Robox vibrate just a little like a sewing machine zigzagging in sub-1mm distances when it fills in the empty spaces)

[Runtime Print]
First Layer Speed x: 0.5 (This is optional and just my preference. Leaving speed at 0.5x can leave streaks and stringy parts so remember to change back to 1x)
Subsequent Layer Speed x: 1
Start Time: 2:05pm PST
End Time: 7:31pm PST
Support Print Time: ~1.5 hrs
Model Print Time: ~4 hrs
Total Print Time: ~5.5hrs

[Cleanup]
I used a kitchen knife to separate the MeshMixer support layer from the model. The video below used a thin spatula. I placed the print flat on table and slowly separated the support. MeshMixer support is kinda tough so be careful with your fingers. Once the layer was removed, the tough part is to use a small flat screw driver as in this video to loosen the ball bearings:

The ball bearings aren’t perfect spheres and have lots of friction so be careful when trying to spin the rings. Squeeze on axle joints before rotating the rings.

 

• This topic was modified 2 months ago by  robyneil.
• This topic was modified 2 months ago by  robyneil. Reason: Added material type

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[robyneil @robyneil My Robox is a Blue Commercial Version]

I couldn’t attach STL but here’s a shared link:

https://www.dropbox.com/s/b5knf137xdmj1l0/ball_bearings_support_combined.zip?dl=0

let me know if link doesn’t work. The license for the model says it should not have any derivatives so I couldn’t upload to thingiverse.

[click @click My Robox is a Green Kickstarter Limited Edition]

@robyneil well done!

[pelgrim @pelgrim My Robox is a Green Kickstarter Early Bird]

this is wonderfull news.
I posted this object a while ago and the reaction was that this would not be possible for like
another half year or so.

java (EE), JavaFX, HTML, GIS) programmer, database wizard, framework inventor, looking for a job ! http://roboxing.com/wizards

[robyneil @robyneil My Robox is a Blue Commercial Version]

Thanks @clicky, @pelgrim. Maybe by AutoMaker 2.0, we’ll get better support generation on overhangs so we won’t have to use MeshMixer.

I was thinking that the best way to print this is to print the ball bearings separately and sand/machine them first. Then when we print the actual rings, we can pause the print insert the cleaned ball bearings, and resume print. We have this advantage over other printers, why not use it? What matters imho is the final output. The best part is we can print the model without ball bearings…no need to add support material at the bottom. This will cut down print down to probably around 3hrs.

[Steve N @discosteve My Robox is a Blue Commercial Version]

@robyneil that’s kind of cheating though isn’t it?

Steve N | Creator of things both virtual and physical

[robyneil @robyneil My Robox is a Blue Commercial Version]

It is just a preference. I guess to me it is more like different ways you complete a scaled modeled kit/build from Tamiya. You can either:

1) Clip the plastic parts “as is” from frame, glue them together, and put on decals.

OR

2) Clip the plastic parts from frame, sand the nubs left out from clipping and smoothen them, spray paint each part with primer then with paint, add more detail painting on each of the model parts like the cockpit, then assemble them (probably will take weeks to months to do where Gundam modelers take around 3-6 months to complete a project).

With the way it was designed, you don’t have the opportunity of making the ball bearings as smooth as it can be especially after you remove the support layer. Loosening actually damages the rings and the ball bearings. The printed model will never be as good as it can be.

[Ian @datman]

@robyneil good answer! Also maybe you could put real steel balls in it, but I guess its really only for show and does not have an actual purpose.

• This reply was modified 2 months ago by  Ian.
• This reply was modified 2 months ago by  Ian.

[robyneil @robyneil My Robox is a Blue Commercial Version]

Thanks @datman

[click @click My Robox is a Green Kickstarter Limited Edition]

@robyneil Oh, I do not see it as cheating. Printer itself is a hardware + its internal firmware. These two + filament are what produces print. How is that print going to be prepared and sent to the printer is different thing.

If you prepare object in one program, then update it in another, add finishing touches in third and print through fourth - still not cheating. You could say AM (actually Slic3r or Cura) are not up to task preparing support for the object - but it is definitively not cheating.

And last thing which I was, kind of, refraining saying being afraid that I can slightly kill the mood: but final result (given slicer + filament - as they may or may not be somehow responsible) is still not close to what we’ve seen somewhere else. Balls are still not finished well on the top and rim has some issues in it.

Don’t get me wrong - it is quite a big step for Robox and step in right direction. If CEL produces equally big next step, we’ll be able to compare Robox with some of better others printers.

[pelgrim @pelgrim My Robox is a Green Kickstarter Early Bird]

3D printing is cheating, so who cares to cheat just that little more,
it’s all about getting the result.

If I would need a similar contraption in a piece I order myself a bag of small metal balls,
they are available at all these online magnet stores, and insert these halfway the print.

3D Printing is not invented to create the perfect sphere.

java (EE), JavaFX, HTML, GIS) programmer, database wizard, framework inventor, looking for a job ! http://roboxing.com/wizards

[Steve N @discosteve My Robox is a Blue Commercial Version]

my comment was sort of tongue-in-cheek

there is something very cool about printing something that is physically impossible to create any other way - the NASA wrench was a good example, people I’ve shown it to are amazed that the ratchet was printed as-is inside the case

Steve N | Creator of things both virtual and physical

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