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Braking System

Measurement and Calculation about the furnace

For the calculation, some parameters of the furnace were collected. Here are the data:


The melting point of copper is 1083.4 J

Density of Copper: 8900 kg/m3


The melting point of iron is 1530 J

Density of iron: 7830 kg/m3


Parameter of the furnace:


Downward force: 4.55kg=4.55x9.81=44.636N

Upward force: 13.64kg= 13.64x9.81=133.808N

Max. Torque   =RxF




Rotational speed: about 3 sec. for 100o

=1/10.8 rps= 5.56rpm


Power required: Torque x Rotational speed



Since the force that needs to move the furnace downward is smaller than upward due to the shifting of the centre of gravity. That means if we want to rotate this furnace, the required power is at least 70W.


The minimum diameter of shaft to resist the rotation of furnace:

Yield strength of the steel(n): 250-690 MPa




So the minimum diameter of the shaft is 13.078mm, but to ensure the shaft can resist the rotation as a factor safety, we use the diameter of 20mm shaft.