Originally Posted by
handlewanker
I would just like to say one thing....the further up the pole you go the more the pole deflects.
A boring bar is considered to be at it's maximum practical rigidity at 4D, or 4 times it's diam stick out......you can just get away with 6D, but deflection becomes a factor in accuracy of the bored hole, no matter how fine the final cut.
In the design in post #1 the column is approx 10 X it's base area in length.
The same applies to the design in post #5.
A column of 1200mm height should have a base at least 300mm in width and at least 400 mm in depth (back) to resist deflection, and the sides sloped to resist deflection.
I refrain from commenting on the use of the square tube for the column and base in post #1.