Modelling a lego brick part 4

9. Now we've hollowed out the brick we need to create the cylinders/bosses that sit between the studs of other bricks and keep the bricks stuck together.

To do this press S to bring up the sketch toolbox, then type center and select "Center diameter circle". Now click on the inside top surface of the shelled brick, and draw a circle of 4.8mm approximately in the centre.

10. Now draw another circle around the last, this time make it 6.5mm.

11. To correctly position and then pattern this "boss", we need to use some construction lines. press the S key to bring up the sketch toolbox, then type "line", select the line tool, then draw a pair of lines from one corner of the brick to the other on both sides.

Press escape to finish drawing the lines.

Now, ctrl/command select both lines and press the "X" key to turn them into dotted construction lines.

12. So we don't have to draw out two more of those circles and do more measuring - we can again use the rectangular patterning tool to complete this part of the brick.

press the S key to bring up the sketch toolbox, type pattern and select rectangular pattern, select the two circles, then select the vertical movement arrow, change the bottom Direction field to "Symmetric" (both directions :-)), the quantity should already be set at 3 if not correct it, then select distance as 8mm and press ok. You should now have three of the bosses.

NOW PRESS "STOP SKETCH"!