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combinations. An asterisk (*) indicates those combinations that are more
typically useful.
The format of this list is as follows:
X=check box on.
O=check box off.
One group of settings is made up of the three Move check boxes over the three
Rotate check boxes. Here's an example:
XXO=X and Y Move check boxes on, and Z off.
OXO=Y Rotate check box on, and X and Z off.
1 1 Move Lock: Turn on any single Move. (This is like a long pin sliding in
a loose, long slot.) The joint can transmit force in one direction only.
The objects can slide with respect to each other in two directions and
rotate freely.
2 2 Move Locks: Turn on any two Moves. (This is like a sliding ball joint;
a freely rotating joint at the end of a sliding shaft, which can slide and
rotate in a hole.)
3 * 3 Move Locks: Turn on three Moves. (This is like a ball joint, or the
theoretical "pin joint" of the statics and dynamics texts, in that it transmits
any force but never transmits any torque.)
4 1 Move + 1 Rotate (unique): Turn on any one Move and any one Rotate,
but not in the same column. (This is like two long pins, parallel, sliding
in a single long slot.) The joint can transmit force in one direction only
and restrain rotation about the axis of the "pins." This combination is of
limited application.
5 2 Moves + 1 Rotate (matching): Turn on two Moves, plus one Rotate
turned on that's in the same column as one of the selected Moves. (This
is the same as 1 Move + 1 Rotate, above, except that the pins can no
longer slide vertically in their slot.) If the assembly rotates so that one
pin travels further into the slot, the other must ride higher in the slot.
This is of limited application. The possible check box combinations are:
XXO XXO XOX XOX OXX OXX OXO XOO XOO OOX OOX OXO
6 * 2 Moves + 1 Rotate (complementary): Turn on two Moves, plus one
Rotate that's not in the same column as any of the selected Moves. (This
is a sliding universal joint like the splined output shaft between the
automatic transmission of a rear-drive car and the drive shaft.) It can
transmit torque and constrain translation in two directions, both
Dynamics Utility | 3859