Enabled metal plate connectors for the 4/4 and 6/4 scissor trusses:



Each truss type and configuration needs its own special function to locate and auto-size each plate.  The code required is not difficult since most of it can be recycled but it is still time consuming to generate for each and every truss type with all of the many possible configurations.  I have not even considered raised heel trusses yet.  At some locations (ie. heel plates on a scissor truss) the truss configuration may cause the plate to fall outside of the perimeter of the truss in this case some additional logic is required to check for these instances.

View model here:

https://3dwarehouse.sketchup.com/model.html?id=16954124-d987-4a72-be11-5089a6be6221

As an interesting side note, one can turn off the truss layer and then measure the volume of the steel plates which yields 113.85 in³.  Multiply this by 0.284 for mild steel and you end up with a total weight of 32.3 lbs.  That is actually quite a bit of steel plates in this rather small truss package.  No wonder the truss plate manufacturers like Mitek make so much money on the sale of truss plates, the volume of steel is definitely there (194 plates).

The weight of the wood can just as easily be computed, making an assumption on the wood species (G, specific gravity of the wood), and moisture content (typically 19% at dry service conditions).

The appropriate equation to use for the density of wood can be found in the AWC NDS:

http://design.medeek.com/resources/documents/NDS2012_SUPPLEMENT_P12.pdf

For DF No. 2 the density would be 34.2 lbs/ft³

The volume of the wood is 22.06 ft³, multipled by 34.2 lbs/ft³ yields a total weight of the wood at 754.5 lbs.  Steel plus Wood = 786.8 lbs.

It may be useful to provide weight information at both the truss component level and the entire truss assembly, wood, steel and total weight.

Enabled connector plates for the common gable truss:



There gets to be quite a bit of geometry when you start modeling all of the plates, especially the gable trusses with all of their vertical studs.

View model here:

https://3dwarehouse.sketchup.com/model.html?id=0f1b6741-f503-43e9-a627-663ceabec33b

What I think I will do is add in one more option in the global settings which allows one to toggle the plate sizing to either auto or manual.

If auto is selected I will create a basic algorithm that looks at the truss span, truss pitch and depth of the TC, BC and webs and then sizes the plates accordingly.  I already have such an algorithm built into my Truss Designer here:

http://design.medeek.com/calculator/calculator.pl

If manual is selected I will have an additional html input screen appear that shows the location and size of each plate as well as the outline of the truss.  The input will look similar to this:



As each plate is adjusted it will immediately change in size showing exactly the configuration of the truss with its connector plates.  This involve quite a bit more coding however once I create one such html input, creating more will not be such a big deal.  Each plate will be labeled P1, P2, P3 etc...  Typically the location and rotation of each plate will have an optimal setting that does not need user input or adjustment.

The only question now is how to handle the gable end trusses.  I think for now I will auto-size the plates on them using the same heel and peak plate sizes as the common trusses.  For the the vertical studs I can use an algorithm that looks at stud length and then chooses either a 1.5x3 or 2x4 plate for connection to the top and bottom chords.

Adding connector plates adds a whole new level of complexity, but there have been enough requests for it that I think it is a valid endeavor.  After all this is the "Truss Plugin" and I might as well get the trusses right.

Version 1.7.1 - 12.08.2016
- Added truss connector plates within the global settings, plate thickness can be specified.
- Added a "roof_mpc" layer for roof truss plates, connector plates can be assigned to a specific layer.
- Enabled metal plate connectors for the common fink truss.



As with the recent layer upgrade I have only enabled connector plates for the common fink truss.  This is to provide a test bed for the connectors then once the interface is fined tuned I will roll it out for all truss types.

At the moment the plate sizes are hard coded in.  I am still trying to decide on the best method to use so that the connector plates can all be sized by the user.  The objective is to make this a flexible as possible while at the same time not over complicating things.

View model here:

https://3dwarehouse.sketchup.com/model.html?id=8e1d46c3-e1e2-4bc9-b16b-69aa1085c8d1

I've had a number of people asking about adding in the connector plates for the trusses.  After giving this some thought it doesn't seem like too much work to implement.  I will try and work on this today and this evening.

I've already added in the option into the global settings:



Plate thickness can be set by the user (inches or mm).  The default will be 0.0575 inches (1.46 mm) which is the total thickness of a typical Mitek M-16 connector plate:

http://www.icc-es.org/reports/pdf_files/ESR-1311.pdf

If I could find some additional help for programming that would be useful right now.  I've come to the realization that I cannot realistically program all of the stuff I have planned.  I really need to expand this beyond a one man show.

I've really only been working on the truss plugin for about a year now and there is a lot more to be done as well as two more plugins that I am hoping to get started on into the new year:

Medeek Structural Plugin



Medeek Wall Plugin



The structural plugin will deal less with the actual framing geometry and more specifically with the lateral and vertical engineering of the structure.  It will be geared toward other structural engineers with the intent to automate residential structural engineering as much as possible.

Lateral:
Wood Shear Walls (segmented and perforated), Diaphragms (roof)
Vertical:
Beams, Headers, Joists, Rafters, Footings, Posts, I-Joists,
Uplift:
Rafters, Trusses

What will make this the killer app is that the 3D model will be able to automatically propagate the loads down through the structure while at the same time allowing the user to create the structure's geometry in an intuitive and friendly 3D environment - SketchUp.

Of course the real power of such a plugin only becomes apparent when you create a model and then decide to build that same house or structure in a different location with different site criteria.  Rather than having to start from scratch you simply enter in the new wind speed, ground snow load, and seismic design criteria into the model and the plugin recalculates the entire structure and then alerts you on any members that are undersized or over stressed.  This would be particularly beneficial to homebuilders who have a set number of model homes they use but build in various locations.

Version 1.7.0 - 12.04.2016
- Added a "Layers" tab within the global settings; roof, wall and floor components can be assigned to specific layers.
- Enabled custom layers for the common fink truss.

Note that I have only enabled custom layers for one type of common truss (fink).  To enable custom layers for all other truss types, rafter roofs and other misc. items will take a few hours of going through each module of the plugin and adding in the "layers" code or conditional statements.  My arm/neck is not holding up very well but I thought it would be nice to at least get this out there for the most common truss type for testing purposes and feedback.

Version 1.0.6 - 12.03.2016
- Added a "Layers" tab within the global settings.
- Enabled custom layers for both stemwall and slab on grade foundations.

I haven't fully committed yet to coding all of my engineering calculators within the SketchUp API, but I am heading that direction as I further contemplate my next Sketchup Plugin: Medeek Structural Plugin.

The largest obstacle is the ability to generate MS Excel files and PDF documents (reports). For this to really work I need a way to have my plugin's calculations export their data into nicely formatted spreadsheets and/or PDF reports. I have no idea where to even start and don't even know if this sort of thing is remotely possible with SketchUp, the API or Ruby, I'm assuming it is because I am sure other people have run into this same sort of thing as me.

Any assistance or direction in this regard would be greatly appreciated.

Ultimately, I am hoping to create a structural plugin that will allow an engineer to do all of the lateral and vertical calcs for a typical residential or light commercial wood structure. The reason for using SketchUp for this sort of thing is the ability to leverage SketchUp's intuitive drawing interface to create all of the building primitives/elements and provide an easy to use method for viewing and inputting building geometry and other design criteria.

I've actually had the idea to create this type of program since about 3 years ago but the show stopper was always the graphical interface and 3D component of it. Not until I began tinkering with the API about a year ago and waded into a full blown plugin development (truss plugin) did I realize the potential available within SketchUp. SketchUp and its API solves the 3D interface hurdle magnificently and now I am hopefully on course to create the one piece of software that will be the apex of my engineering career and hopefully further automate and advance the field of residential structural engineering.

I've been thinking about adding in a retaining wall feature that auto sizes the rebar and qty. based on my typical retaining wall details:



For stemwall foundations I typically check the footing width (bearing pressure) and min. rebar for shrink (ACI 318-11), see engineering calcs per this PDF:

http://design.medeek.com/resources/footing/STEMWALL_FOOTING_CALCULATOR.pdf

I could easily incorporate this type of engineering calculations into the plugin, however I'm still trying to figure out how to have the plugin output PDF reports, or Excel spreadsheets, which would be necessary if engineering reports become part of this plugin.

Same sort of thing with square or rectangular footings can be done:

http://design.medeek.com/resources/footing/SQUAREFOOTING_CALCULATOR.pdf

With stemwalls or pony walls (not necessarily retaining walls) that exceed 24" in height (but not in excess of 48") I like to add #4 bars cont. horizontal at 18" o/c.  Logic could be incorporated that adds in additional stemwall and foundation wall rebar per a number of prescriptive criteria, IRC tables etc...

Currently it is entirely up to the users to specify rebar size and qty. with both stemwall and slab on grade foundations.

Stemwall foundations allow you to place rebar at the top of the wall  (5" below top, qty. 1,2, or 3 bars) and rebar at the bottom of the wall (3" above bottom, qty, 1,2, or 3 bars).  It also allows placement of bar in perimeter footing and interior footings (qty 1,2 or 3 bars).  Bar sizes range from #3 to #8 and similar sized metric equivalents for the metric templates, I can always add more sizes if requested.

Version 1.0.5 - 12.01.2016
- Enabled reinforcement for stemwall foundations.



View model here:

https://3dwarehouse.sketchup.com/model.html?id=ef2187c3-eec9-487f-ae38-601f128390f1

Version 1.0.4 - 11.27.2016
- Enabled rebar and mesh reinforcement for slab on grade foundations.

I've repackaged the .rbz file this morning so that when it installs into SU 2017 the extension will have the appropriate hash file and appear as "signed".  I have not yet rolled the revision (1.7.0) which includes the updates for stepdown hip truss sets, there is still substantial work before I am ready to release that module and version.

I've recently uploaded my latest volume of residential structural details to the CAD Library.