I'd like to open a learning discussion on building these for those that have or intend to do it.

I haven't built many - people 'round here don't wanna pay for them. I've only built 3 actually. The one I finished today is 50" wide and 38" tall, built for a 9' ceiling.

I design them in SketchUp and them import them to render with my cabinet program for the customer. I use SketchUp to dial in the radii and critique everything so I know it will work. I think there are programs out there (I haven't looked) that will do all this automatically, but I'm not willing to fork over the mullah for rare instances.

1. Build the base of the hood to specs determined by the vent hood.
1a.) Can this be standardized for 30, 36, 42, and 48" ranges? I should think so.

2. Use Sketchup (or math) to build curve and determine radius needed for sides and front.

3. Build a jig to cut the plywood skeleton of the frame. (I didn't take pics, but the skeleton looks similar to this pic [but I use more ribs])

4. Pocket drill skeleton so it's easy to mount to frame later on.

5. Figure out why the corners are a different radius than the front and sides. Anyone know? Math friends? I figure it out by determining the rise and run using scribe marks. But I'd like to know the formula.

6. Preskin with 1/8" MDF. It flexes easily and takes contact cement really well. Sides first - I clamp them to the skeleton and scribe a line to trim on the band saw. I trim +1/8" and use a laminate router with flush trim bit to fit it perfectly. I glue and screw the MDF to the frame by predrilling and countersinking the MDF on 4" centers (I don't want it to move or buckle). Then I do the same to the front. I have to be careful where my countersunk screws are along the edge when using the flush trim bit.
6a.) Flush trim along a curve isn't hard, it just has to be done free hand where only the bearing is touching material. I used a 1/4" shank, 1/2 dia x 1.5" bit. 1/8" MDF doesn't bite, especially if you trim close to your scribe line. Just be careful of the angle so you don't gouge a side or the front.

7. Apply paper back veneer (1/32) using contact cement - same as for laminate countertops. I have to apply 2 coats to the MDF, the first coat gets soaked up. First hood I built using this method had a couple bubble develop (which I stripped and sanded then reapplied with success).

8. I scribe and cut with a box knife +1/8" of the scribe line. After gluing and rolling it, I flush trim with the same method as on the MDF. I buy extra veneer in case I sneeze while trimming.

9. Use a ROS and 180grit paper to sand the edges and everything to denib. The joints are so clean you can see how they were joined.

10. Screw to the base.

I feel much more confident in building these now that I've completed 3. I'll post pics of the final product next week after it's installed and finished. And I'll definitely take detailed pics of process next time I build one.

I'd love to hear/learn about other (better?) methodologies and possible standardization. Even if it involves CNCs.