A drill rod in 60" will be hard to find.
IS that 60" one rod? and how is that supported? How accurate do you want this to be? What sort of weight will they carry?
FYI
A 60" 1/2" drill rod 'fixed' mounting at either end with a 10lb load at 30" will deflect ~0.13"
A 60" 3/4 drill rod 'fixed' mounting at either end with a 10lb load at 30" will deflect ~0.026"
For simple support at both ends those figures become 1/2" = ~0.52" deflection, 3/4" ~0.1" deflection.
For a *really* rough estimate within a small margin if you double the weight the deflection would double too.
note for a home built machine the actual rigidity of end supports would be somewhere between 'fixed' and 'simple'. 'Fixed' meaning absolutely no movement, not feasible unless the machine is really massive. The much used idea of adjustment blocks with four bolts around the shaft would be more or less equivalent to a 'simple' support. |