I have a unique part - I can't attach a model of - due to it being a customer file....and disclosure rules....so I'll try to describe as best as I can.

Ok, This is a velocity nozzle for an exhaust sytem.  Ducted fan sits under unit.  It has an outershell, that is essentially round (48in dia.). the inner structure is conical (smaller toward the top) ... center is hollow - no airflow thru, airflow is between conical section and outer shell.  These are split in 180 degree halves.  2 halves make a unit.

What I need to do, is wrap the inner conical piece with perforated metal - the customer has provided prints in PDF format which don't work for me.

I do have CAD models of the inner and outer cone, but not of the sheetmetal.  First thought - obvious - get models from customer.  Not as easy as you would think.

So, I'm looking at creating the missing pieces - why - to send to our perf vendor to waterjet flat patterns....so our guys don't have to hand cut with tin snips.

I'm able to create a 3D sketch - and copy the edges of the lower large diameter and smaller upper diameter ring, as well as the side edges - which are curved as well...

Once I have the 3D sketch  - i copy and pasted into new part drawing.

I then tried a surface fill - but got less then desirable results.  It had ripples in the surface.  I then added a guide rail from center quadrant to center quadrant of the conical shape.  got better results but still get uneven surface.

my thoughts, once I got the surface was to convert to sheetmetal then unfold or create a flat pattern.

Am I going about this the wrong way?