(created on 8/1/07)

The crane is highly adjustable.  It may be raised or lowered slightly by making the base wider or narrower.  The crane can also be raised/lowered more by raising or lowering the A-frame.  

Raising and lowering the crane by making the frame wider or more narrow (small adjustments to height)

This procedure is done one side at a time.  It requires at least two people (three is easier).

1.  Apply force inward (as if to try to make the crane more narrow) to both pillars. 

2.  While continuing to apply force, remove the safety pin and fatter pin from the bottom cross beam.  The weight of the I-beam will try to push the A-frame wider (lower).  To make the crane wider (lower), stop applying force to one side.  The bottom cross beam will become wider.  To raise the crane, both sides will have to push inward.  Whether raising or lowering the crane, make sure not to extend the crane past the "last hole," which should be clearly marked.

3.  Replace the fat pin and safetly pin.

4.  Repeat on the other A-frame.

Raising and lowering the I-beam (larger adjustments in height)

This procedure requires many people and the use of eyelets in the ceiling.  Straddling the vacuum chamber is an excellent place to do this.  This procedure must also be done one side at a time.

1.  Attach the I-beam of the crane to two eyelets in the ceiling with two handcranks.  (This will require someone to be seated on top of the chamber).

2.  Raise the crane so that the weight of the I-beam is no longer supported by the legs of the crane.

3.  With two people holding each side of the A-frame, remove the two spring-loaded safety pins.

4.  To raise the crane all four people push up on the A-frame posts.  The top of the crane will rise while the bottom remains on the floor.  This will require significant force from the four participants.  To lower the crane, lower the I-beam and guide the four posts down to the desired height.  This requires much less force.  Make sure not to raise/lower the crane past the "last hole," which should be clearly marked.

5.  When the desired height is achieved, replace the spring-loaded safety pins.

6.  Repeat on the other side.

 Create your own educational wiki!HelpPublic, not yet premium Privacy Policy RSS