Most drawings these days seem to be drawn in the Third Angle Projection, whether stated or not.
I am machining a Stuart Turner centrifugal pump, the castings for which are quite old, or at least are no longer available. There was no information on the drawing sheet as to what the projection was, so naturally I assumed (deadly) that it was Third Angle.
Laid out the bolting circle and mounted up the cover plate on the rotary table to drill the 5 securing bolts, which were not of a symetric pattern. It was only when I had gone round with the centre drill and casually looked at the pump body that I realised that one hole was in the wrong place.
Some silver solder should hide the errant hole (the smaller one at 10 o'clock), which fortunately did not go all the way through.
Moral of this sad tale: Always make sure you realise which projection the drawings are in, particularly if they are of an older design and probably of British origin.
Dave
The Emerald Isle
I am machining a Stuart Turner centrifugal pump, the castings for which are quite old, or at least are no longer available. There was no information on the drawing sheet as to what the projection was, so naturally I assumed (deadly) that it was Third Angle.
Laid out the bolting circle and mounted up the cover plate on the rotary table to drill the 5 securing bolts, which were not of a symetric pattern. It was only when I had gone round with the centre drill and casually looked at the pump body that I realised that one hole was in the wrong place.
Some silver solder should hide the errant hole (the smaller one at 10 o'clock), which fortunately did not go all the way through.
Moral of this sad tale: Always make sure you realise which projection the drawings are in, particularly if they are of an older design and probably of British origin.
Dave
The Emerald Isle