Walt & I

In 2018 Walt Gillespie, owner of Rusty Stumps Scale Models and I were talking (via email) about how to model HVAC. Walt had previously created a couple of HVAC units in seveal scales but what lacked was the ducting. I volunteered to work the issue and created a VAST number of assorted duct fittings to fit Evergreen tubing.

Recently, Walt sold the rights to his structures. Laser Cut Details and at least some of the 3D prints (not sure about how much of the latter) to Rail-Scale-Models.

Roof-Top HVAC System

I find it interesting that the photo shown .. the .. “pilot model construction” is the same one in the two videos.

Test Build

The following videos show a test build I did. Walt sent me some pre-production fittings .. the first ones he did so it took a bit of “figuring out” to come up with a little HVAC scene that made use of the limited fittings I had. I think it worked out fine for a little display

This first video just shows the parts being assembled virtually. Note that the sequence of tubes and fittings can be varied to fit your own design .. you have a lot of leeway to make tubing longer or shorter, turn elbows in another direction and so on.


This video pretty much follows what I did virtually in Sketchup. Again .. certain fittings fit certain size tubing but the arrangement, length of tubing and so on are to a large extent up to you.