Finding hole centre's in cylinders, how?

Hi,
I am making a sheet metal cylinder like an emersion heater. There is a hole
in one side of the cylinder into which a tank fitting is inserted. Here lies
my problem. When in the flat state, I am able to position the hole and also
to insert an Axis, but when the flat sheet is rolled up( unflattened), there
is no Axis, as this is left on the flat sketch! Now in an assembly, because
the hole is no longer a round hole and the surface of the sheet is no longer
Linear, I can not put any constraints between the tank fitting and the
cylinder. The only way I have found is to use 2 planes, 1 vertical and 1
horizontal to the hole centre, draw 2 line sketches, then constrain to
these.Blooming lots of work when more than 1 hole !!! And also no constrain
of the fitting to the suface of the cylinder! Any ideas please??

 

Could you make the fitting tangent to the edge of the hole? Then put
a distance mate from a plane at the center of your cylinder to the
bottom of your fitting?

Ken

 

I don't do much sheetmetal work, but I think I would try putting the holes
in, while the cylinder is in the unflattened state.

Jay

 

Depends on what he wants. If he puts the hole in the flat, he ends up with a
distorted hole when he wraps the cylinder.

Jerry Steiger
Tripod Data Systems

 

You must cut the hole out in the formed state. Otherwise you will
have to keep using your creative mating.