83. Axes convention on CNC HMCs
CNC – Axes convention on CNC Horizontal Machining centers
The spindle is ALWAYS the Z axis.
The right hand rule is used to determine the linear axes and their direction. The middle finger is the Z axis, the thumb the X axis, and index finger the Y axis. The fingers also show the Plus directions.
Rotary axes about X, Y and Z are called A, B and C respectively. Another right hand rule determines these axes. If you point the thumb towards the Plus direction of the linear axis, the other curled fingers are the direction of the rotary axis.
Auxiliary linear axes are parallel to the primary axes. Auxiliary axes parallel to X, Y and Z are called U, V and W respectively. The quill on an HMC is an auxiliary axis, and is called W.
Pics. and text source: Cadem NCyclopedia multimedia CNC training software.
Mango shop on a bullock cart – Chennai
I saw this unusual sight of mangoes being sold from a bullock cart on a Chennai street recently. Unusual because bullock carts are used to transport, not sell from. Also unusual because bullock carts are becoming an increasingly rare sight in Indian cities (sadly for me – I’m a strong votary of non-motorized transport). The owner of this mobile shop said he WAS selling his mangoes from the cart for the novelty value, to set him apart from nearby static shops. Note the ubiquitous Amma poster at the back.
The mangoes being sold were the Imam Pasand variety. The Imam Pasand is a very sweet, large, spherical mango with a very thin skin. Mostly grown in AP. Looks like an orange, and almost violates the term ‘mango-shaped’. The name means ‘the Imam’s favourite’, an Imam being a Muslim religious leader. It’s also called the Himayat.
Nobody seems to know how the name originated – maybe some famous Imam’s favourite fruit, or the emperor Humayun’s favourite? Humayun was the father of Akbar and great-grandfather of Shah Jehan, who built the Taj Mahal.