Tuesday, September 15, 2009
Big Bertha the beginning
Big Bertha begins with Legs made from the B&Q CLS timber 38mm x 68 mm (low cost @ 1.94 for 2.4 M) Big Bertha will have a work area of 600mm x 1200mm or 4' x 2' feet
Bed will be supported by two 5' sash cramps the Y axis gantry held together with 10mm threaded bar sliding on 20mm hardened rails with pukka CNC linear bearings with the z axis supported on 16mm more hardened rails with CNC linear bearings.
I ordered some 1/2 " industrial roller chain from the USA with the idea for driving the x axis on chain as its 1.4m long thinking threaded rod would flex when turned at speed unless it was really thick.. I may revert back to a drive shaft if chain is not as good as I anticipate.