Version 1.3.4 - 03.02.2016
- Corrected a bug in the metric unit template module.

28' Bow Barrel Truss (8/8) study.





View model here:


https://3dwarehouse.sketchup.com/model.html?id=ub4c69c4f-ae02-4ad8-b17b-5eecb8d31823


Gable end trusses for this type are a bit of a question right now.  I can add this one into the plugin if there is some call for it, but I may hold off until a request is made since the code will be somewhat tedious with all the separate members that make up the top and bottom chords.

Added Bowstring truss type, configurations: (8/8).



View model here:

https://3dwarehouse.sketchup.com/model.html?id=uad891cf8-30ad-4d6f-ae10-a8b7f10a2114

Initially I wasn't really sure how to lay out this type of truss, especially the webs and panel distances.  Then after some thought it occurred to me that the length of each top chord segment should be roughly equal to best approximate the circular shape of the truss.  After some checking of existing shop drawings my theory tested correct.  The length of each top chord segment is equal in length.

Version 1.3.3 - 02.28.2016
- Added Bowstring truss type, configurations: (6/6).
- Metric input enabled for bowstring truss type.



View model here:

https://3dwarehouse.sketchup.com/model.html?id=udee2767c-3da1-40b9-8d07-9e1e36989d4a

I'm not sure how common place this truss type is anymore so I will add the advanced options at a later date if requested by a user.  I can also add in other configurations with more panels if needed (ie. 8/8, 10/10).

A quick study of the general shape and layout of a 6/6 bowstring truss with different radii:

Mono Cathedral trusses with heel wedge:



View model here:

https://3dwarehouse.sketchup.com/model.html?id=u5c030ac2-f2e4-4c8d-8d9b-67bfa780ee7f

Version 1.3.2 - 02.23.2016
- Added Dualpitch truss type, configurations: (2/2-3/3).
- Metric input enabled for dualpitch truss type.
- Advanced options enabled for dualpitch truss type.



View model here:

https://3dwarehouse.sketchup.com/model.html?id=u9b6a5e53-76c4-4c9b-bce3-aaa8ffba4c36

Here is a Dual Pitch 2/2 - 3/3 truss with a 12:12 pitch and a 4:12 pitch.





Still working on the gable end trusses and the advanced options involving structural outlookers.


I will be looking at raised heel scissor trusses next, those sound challenging and interesting.  Please post or send me examples of any raised heel scissor truss examples or shop drawings.  The combined pitches of the top and bottom chord with a wedge, slider or vertical web and strut will require some serious calculations and ample logic.

Started to code in the dual pitch truss, the top chords, king post and bottom chord are there just need to add some webs:



Just an FYI, my previous post in Nov. had a sign switched in the last step of the derivation for Span 1, corrected in the plugin to a minus sign and everything is comes out perfect.

Version 1.3.1 - 02.17.2016
- New submenu item and toolbar icon added for global settings.

I've been looking at a number of garage designs recently that employ an attic or storage truss.  I'm finding that a lot of them tend to use raised heels to allow for more head room while having a lower roof pitch (ie. 6/12 - 8/12).  I'm thinking about adding in raised heels for the attic truss type in the plugin. 


A quick mock up would look something like this:





View model here:


https://3dwarehouse.sketchup.com/model.html?id=u208d64e3-ddcf-4923-8dfb-d507185fa663


Ignore the unbalance in the panel lengths, in practice and in the plugin they will be properly balanced. 


What I do have a question on is the use of a top chord splice as shown in the above image so that the overhangs do not have to be as deep as the top chord in the non-triangulated region of the truss.  I have never seen a splice used on a attic truss with a raised heel, I don't see why it can't be done but it is always nice to have a confirmation that someone else is doing this sort of thing in practice.

Version 1.3.1 - 02.15.2016
- Added Triple Fink and Quad Fink common truss types.
- Structural outlookers (vert. & horz.) enabled under advanced roof options for Common (Triple & Quad Fink) truss types.


Triple Fink @ 70' w/ 2x6 chords
Quad Fink @ 80' w/ 2x6 chords

View model here:

https://3dwarehouse.sketchup.com/model.html?id=u2b57ed6d-9f1f-47c4-9e09-5489940c94b2

Alternatively one could balloon frame the wall at the gable ends and attach a ledger for the ceiling:





View model here:


https://3dwarehouse.sketchup.com/model.html?id=ub1aa30d4-a7c3-4320-8bc4-03fd128b5913


In my opinion a partially sloping wall gets complicated to frame.  From an engineering standpoint the balloon framed wall is also the strongest option.

I am currently investigating the best method to construct the gable end wall and truss with a tail bearing truss.  Show below are 3 different possible configurations:


1.) Structural Outlookers (Vertical)


2.) Non-Structural Outlookers (Horizontal)


3.) Structural Outlookers (Horizontal)

This is just one possible method of framing the gable end wall into the gable truss with a 2x4 outlooker.  Option 3 shown above is somewhat of a question, not sure how that heel joint would come together.

View the model here to analyze the different configurations:

https://3dwarehouse.sketchup.com/model.html?id=u75c42456-c8e5-4002-bc93-779860f8dc61

Version 1.3.0 - 02.14.2016
- Added tail bearing truss type, configurations: (Fink).
- Metric input enabled for tail bearing truss type.
- Advanced options enabled for tail bearing truss type.



View model here:

https://3dwarehouse.sketchup.com/model.html?id=u704b9d92-bd38-4895-b71b-19691f31cca7

I have shown 3 configurations of the same roof to display the differences with non-structural vs. structural outlookers (horz. & vert.).  I am not exactly sure how to treat the gable end truss for this truss type since I have never dealt with this type of truss before.  Any sample outputs showing the gable end truss with a dropped top chord for a tail bearing truss would be very helpful.