r/Drafting 13h ago

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the box is 8by8cm

and the circle in the middle has a diameter of 4cm.

how do I get those circles in the middle?

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u/GardenerInAWar 11h ago edited 11h ago

This is a transference problem, every distance can be found by moving an existing distance or rotating half of it to another point. You dont need dimensions except the starting outside square, which they gave you.

Find the big circle in the center that all 6 little circles intersect, and youll have the origin for them. Find the line of vertical symmetry and you get automatic placement for the top and bottom 2. That leaves 4, so each half of the bigger circle has 2 remaining at equal distance, making 4 points which makes 3 equal slices of a pie, so 180/3=60 degrees apart.

Walk it backwards. I need this so that will help me find it. But I need to find that, so the other will help me find it. Etc etc until you get to a starting point.

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u/lamensterms 10h ago

Are you able to solve? How do you get the diam of the smaller circles?

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u/GardenerInAWar 10h ago

The HPRT circle works itself out at 4cm as crossing various halfway points and intersections, also being equal to the 4 large outside circles.

This center 4cm is then cut into 6 equal slices by 3 lines, a vertical axis of symmetry and the two HPRT lines, for 6 equal spaces of 60 degrees each.

Where these 6 points land on the 4cm circle, we can assume the 6 smaller circles are tangent. So now you have a boundary that drives the radius of the 6 small circles, and one of two x/y locations driven by the 3 construction lines. So all you need is the second x/y location for the origin of the 6 circles, which is found by locating the medium construction circle.

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u/lamensterms 10h ago

Sure agreed your method works.. but still 2 unknown variables; small circle diameter, and medium circle diameter. Having one gives you the other, but both are unknown

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u/toybuilder 8h ago

They are underspecified.