The impressions are cast, trimmed and bases scored as shown and suppied with a wax bite (one shown is a protrusive wax bite for a Twin Block appliance).
Upper & lower models are placed into the wax bite and sealed on the buccal area using a hot wax knife, to prevent the models from moving out of 'occlusion' during articulation.  This is done on both sides.

The simple hinge articulator 'arms' are then 'vaselined' to aid the removal of the articulating plaster (and model) once set.

Also, the 'pin' height is adjusted so both upper & lower models fit easily between the articulator arms.

This slide show details the lower model articulation first, allowed to set, then the next slide show will detail the upper model articulation.  An experienced technician will perform both upper & lower articulations in one method.

v Support the 'foot' of the articulator with one hand whilst placing the models with the other to prevent it from tipping forwards.

v Centralise the models and ensure that the horizontal plane is level.

N.B.  Never allow the plaster to set, covering the 'foot' of the articulator or the upper neck of the articulator.  Otherwise you'll have difficulty removing the models from the articulator. 

The upper model is then articulated.........

N.B.  Ensure that the 'pin' closes to its full position and that the plaster does not cover the 'neck' of the articulator.

The wax bite is then released from the occlusion.
Models removed from the articulator.
The models are trimmed as shown.  N.B.  The articulating plaster that rests up against the 'foot' / 'neck' of the articulator, is not trimmed away, as this acts as a guide to show that the models are in the correctly articulated position when placed back on the articulator .