Designing 90° Sheet Metal HVAC Duct – Advanced Tip 1

Article by James Swackhammer updated April 24, 2019


Making a sheet metal duct can be time consuming but hopefully these few tips can reduce the time it takes. In my previous articles I took you through the process of making a 24 inch diameter, 90 degree HVAC duct. For the second step of the process I showed you how to apply a 0.0005″ cut extrusion slit for sheet metal conversion. I did this through all the bodies at once, which meant, in the final part, I had to cut the DWG in half and join on the opposite side.

Cutting a slit for flat pattern

Cutting a slit for flat pattern

Making the process easier in SOLIDWORKS

Reordering or creating the cut extrude slit after the body split will make the process easier going forward. Like the picture above shows; hit the drop down arrow for Feature Scope and turn off the auto select. Now a box appears, this is where we can select every other body.

Additional sketch

Additional sketch

Another sketch is to be drawn. Use the first slit to convert entities for the center circle, then offset that circle to the outside of the duct. The ends on the duct are now converted to get a connecting line, drag the grab handle on the new lines to connect with both circles. Trim up the remaining circle to get what the picture shows above. With this, we can do an extrude cut to the opposite bodies as extrude cut 1 like the picture below.

New cut applied

New cut applied

With these cuts the same process can be done—saving out the bodies and then converting each to sheet metal. When placing these into DraftSight as a DWG you won’t have to edit them. They can be placed together and sent out to be cut.

Related Links

Certified SOLIDWORKS Services available from Javelin

Javelin can help you to:

Find Related Content by TAG:

James Swackhammer

James is a SOLIDWORKS Technical Support Application Expert based in the Javelin Oakville head office