Tray Trusses working now I just need to enable gable ends and advanced options:



Note the three large trusses are all 36' span with different tray widths and different web triangulations.

View model here:

https://3dwarehouse.sketchup.com/model.html?id=ub0bbdf3a-4749-4e8a-8016-758869f692b6

Tray truss algorithm:



A more complex algorithm would be required for a non-centered tray.

Version 1.4.8 - 04.01.2016
- Added Mod Fan common truss type.
- Structural outlookers (vert. & horz.) enabled under advanced roof options for Common (Mod Fan) truss type.



View model here:

https://3dwarehouse.sketchup.com/model.html?id=u3cf3d051-4d02-4490-af81-5693296cca33

With the addition of the Mod Fan (Triple Fan) the line up of common trusses is complete.  I still need to add in raised heels and structural outlookers for some of the configurations. 

Theoretically I could add in additional configurations of the Fink and Howe truss types for extremely large roofs but the largest I've ever seen is a raised heel Quad Fink (10/9).  Large spans beyond 70'-80' are probably not practical as far as a single span common truss roof.  At that point you pretty much go with large flat roofs with interior columns and girders and all steel construction (think Walmart or Cosco).

Six possible end details for a flat truss (Pratt 4 panels), there are probably others but these seem to be the most common:



1.) Mansard w/ Parapet
2.) Parapet
3.) Mansard
4.) Overhang
5.) Cantilever
6.) None

Both Mansard configurations can also have an optional overhang as shown.  The Parapet configuration should allow for customizing the thickness of the parapet wall.

View model here:

https://3dwarehouse.sketchup.com/model.html?id=ude4e9b15-f67e-40de-a99f-97d2044182ad

This truss type with its many end configurations would work well with an HTML UI, that is the direction I will be going with future user inputs and interfaces since the ability to customize is unlimited.

With the flat trusses I will initially offer both Howe and Pratt with the ability to utilize a low slope or zero slope.

To further clarify the framing details with regards to attic trusses and structural outlookers I've created a sample model with a proposed dropped top chord gable end attic truss:





Please download and review the model here:


https://3dwarehouse.sketchup.com/model.html?id=u8c3afc5c-482a-41ea-b223-988b1cccd8bc


I've also included the infill wall framing to help put everything into reference (light green).


Is this the appropriate way to frame an attic truss (gable end) with structural outlookers?

Just as a word of warning this plugin is far from a polished or finished product.  There are still a lot of loose ends that need tying up.  Case in point I have not yet enabled gable end trusses for the attic truss type.  The reason is the complication of dropping the top chord for structural outlookers where the attic truss has a spliced top chord.  Below is an example of a attic truss with a dropped top chord that I have encountered in the past but I don't know if this is the best method of handling this situation. 





I would like to enable structural outlookers for attic trusses in the next few days just to wrap this up.  Any thoughts or suggestions or examples of similar configurations are very much appreciated.

Version 1.4.7 - 03.28.2016
- Added Cathedral truss type, configurations: (4/X, 6/X).
- Metric input enabled for cathedral truss type.
- Added gable end trusses for cathedral truss type.



Note, that not all configurations have webs enabled however the top chords, bottom chords, gable end trusses and all advanced options are enabled.

A breakdown of the configurations for the Cathedral 4/X family:

I've been meaning to add in cathedral trusses for quite some time and I finally had the chance last night.  Configuration (3) shown below for a catheral 6/X truss:



Now I only need to code in the other six configurations and its ready to release as a new update.

Second look at cathedral trusses (6/X) family:



The logic required to triangulate these type of trusses becomes tedious.

Version 1.4.6 - 03.26.2016
- Added Cambered truss type, configurations: (6/X).
- Metric input enabled for cambered truss type.
- Added gable end trusses for cambered truss type.



Six variants of the (6/X) configuration dependent on the ratio of the camber width to span.  Notice that in all cases the top chord has six panels, the bottom chord varies from 4, 5 and 6 panels.

View model here:

https://3dwarehouse.sketchup.com/model.html?id=ued7e0d19-2843-4b3a-9786-3c15cf876fdf

Another look at the cambered truss:

I had someone ask me if it would be possible to create a small house or cabin based entirely on a raised heel attic truss profile, probably with some skylights for light.  I've never seen this type of design before but I don't see why it might not work.  Has anyone ever seen something like this done?  Basically an attic truss with a raised heel (48') resting directly on a stem wall foundation with post and beams or something similar.







The one issue I could see is if there were no windows for a bedroom (no egress) that was midway the length of the structure.  The design shown is 36' wide, 42' long with a 21' wide attic room.  6"x24" stemwall foundation, with a 12"x6" footing. 

Typically large attic trusses are quite expensive so it would seem that this would be an expensive way to build a house perhaps there is some other reason that makes this method of construction viable?

View model here:

https://3dwarehouse.sketchup.com/model.html?id=u88dea626-2d7e-45cb-8751-6f2f3b101fc5

Version 1.4.5 - 03.24.2016
- Structural outlookers (vert. & horz.) enabled under advanced roof options for Scissor (4/4) truss type.

I guess I somehow missed enabling structural outlookers for scissor trusses.  Anyhow this issue was brought to my attention this evening so I've tried to rectify it as much as possible.  After delving into the code I realized that the scissor truss module needs a major rewrite and cleanup so I was only able to get structural outlookers enabled for the 4/4 configuration.  Later next week I will jump back into this module and work on the 2/2 and 6/6 configuration.

Same truss as above but in SketchUp:



View model here:

https://3dwarehouse.sketchup.com/model.html?id=u93559996-8808-4186-9f65-3065a9d3f64f