Solidoodle: Printing a Lego-Like Block: Success

First, what are the actual measurements we must match?   Taking multiple measurements: Mesauring Brick with Caliper

  • A: Diameter of a nubby: 4.92mm, 4.90, 4.89, 4.89
  • B: Width and Length of a 2×2 square: 15.84mm, 15.89mm
  • C: Height of a brick (ie, 3x a thin): 9.57mm, 9.59mm

Then, using NetFabb against the model (click image to for link to ThingiVerse): parametric_lego_2x2_preview_tinycardMeasuring in Netfabb

  • A: 4.8mm
  • B: 15.8 mm
  • C: 9.6 mm

My guess is that they reduced the size of the nubby because it would ooze a bit; the other two dimensions appear to be about right.  

And the printed out ones:

Slice Scale Flowrate A B C Fit?
0.3mm 1.0 0.6 4.67, 4.82
4.69, 4.79
16.07
15.93
9.64 mm Very Loose

Interesting!  The nubbies are coming out a bit smaller, but the part is a bit bigger.   The height is within 1 layer of where it could or should be.

Now, I want the part to print out nice and snug.  Its hard to measure, but it looks like the receptor diameter for tne nubby is about 4.8mm – ie, they’re using a flex of about 0.1mm to keep things snug.  So, I want to print out with a diameter above 4.8mm.

Lets try something at Flowrate 0.65, just to see what happens:

Slice Scale Flowrate A B C Fit?
0.3mm 1.0 0.65 5.02, 4.8, 4.95, 4.86 15.93
15.84
9.73 Pretty good!

And what do you know!  It fits!  Pretty snug-gly!

3 bricks in a row

Although, due to a hole in the original .STL file, the entire bottom of the piece got replaced with a solid face. 

The missing bottom

Mission Accomplished.   0.65 might be the answer, although it disagrees with the single-wall-thickness calibration.

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