Break the model apart and do them parts by parts.
PUSHER
PUSHER |
PUSHER |
PUSHER |
PUSHER |
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THROWER
THROWER |
THROWER |
THROWER |
THROWER |
THROWER |
THROWER |
PULLER
PULLER |
PULLER |
PULLER |
PULLER |
PULLER |
PULLER |