Calculating rings

[Willy Tschager]

My usual approach placing rings is trail'n'error. I wonder if there is a mathematical way or even a tool which does it for me? I have these cylo:

1 1 50 -37 -10 43.75 0 0 0 0 -43.75 0 10 0 48\2-4cylo.dat
1 1 50 -37 -10 40 0 0 0 0 -40 0 3.125 0 48\2-4cylo.dat
1 1 50 -37 -3.125 40 0 0 0 0 -40 0 3.125 0 48\2-4cylo.dat


and need the external ring.

1 1 50 -37 -3.125 4 0 0 0 0 -4 0 3.125 0 48\1-4rin10.dat

is too large cos the distance is not 4 but 3.75. So ...

w.

[Gerald Lasser]

There is the "Rings and Cones" which can be found in the "Tools"  Menu of LDPE, that gives the following result:

1 16 0 0 0 1.16666666 0 0 0 -1 0 0 0 1.16666666 4-4rin66.dat
1 16 0 0 0 1.28142076 0 0 0 -1 0 0 0 1.28142076 4-4rin61.dat
1 16 0 0 0 1.30242766 0 0 0 -1 0 0 0 1.30242766 4-4rin61.dat



On the other hand, what if you extend the outer cylinder by 0.25 LDU (0,1mm) ? it wouldn't fit?

[Philippe Hurbain]

There is the "Rings and Cones" which can be found in the "Tools"  Menu of LDPE, that gives the following result:

1 16 0 0 0 1.16666666 0 0 0 -1 0 0 0 1.16666666 4-4rin66.dat
1 16 0 0 0 1.28142076 0 0 0 -1 0 0 0 1.28142076 4-4rin61.dat
1 16 0 0 0 1.30242766 0 0 0 -1 0 0 0 1.30242766 4-4rin61.dat



On the other hand, what if you extend the outer cylinder by 0.25 LDU (0,1mm) ? it wouldn't fit?

Yes it's often possible to tweak a bit dimensions to fit simpler ring combos, especially if the overall ring is thin (say above ring 6 or 7)

[Orion Pobursky]

There the ring calculator on my LDraw spreadsheet. It'll help you find the ring combination you need.

[Willy Tschager]

There is the "Rings and Cones" which can be found in the "Tools"  Menu of LDPE, that gives the following result:

Thx, wasn't aware of.

w.