3D Truss Models

medeek

You are making quite a huge extension! Are various members produced in components for modification afterwards? For example one were to modify all tails. I say this because, obviously you are getting close to realistic representation, but if one is seriously using this to show an actual structures, they will want to add modifications, which occur in every building and can't be put into a plugin.

Fortunately, someone pointed this out to me fairly early on so I have made it a point to make certain elements components and groups in a sensible fashion.

Common trusses and rafters are always components so that modifying tails etc... can be done quickly and easily. Other items such as fascia, outlookers, sheathing, beams etc... are not components but groups (solids).

Also now that I think about it the outlookers should also be components rather than just groups, added to the "todo" list.

medeek

Glulam beams in the UK seems to be fairly standardized:

Standard Widths: 90, 115, 140
Depths: 225, 270, 315,360, 405, 450, 495

Ply: 45mm

medeek

All of the pertinent details for I-Joists can be found here:

http://www.woodbywy.com/document/tj-4000/

All have to think about this one. The problem with I-joists is the bevel cuts are more difficult since it requires more operations to model. The outlookers at the gable ends would need to notch around the top flange of the I-joist. A double or single bearing plate is required at the ridge or hangers from the beam, notching at the high end of the roof joist is not allowed. Birdsmouth cut at the low end of the joist is allowed but requires web stiffeners on both sides of the joist.

If I can figure out a good method of making the beveled cuts of complicated profiles that would greatly facilitate things.

Update:

I think if I actually model the I-Joist as three groups, make all the necessary cuts and then union them together I may be able to stick with my simple modeling method points -> face -> pushpull

medeek

With I-joist roofs don't think I would model in any of the web stiffeners, otherwise the model gets too heavy, same goes for small fasteners and hangers.

I haven't even considered the option yet with the rafters resting on top of the beam (dropped ridge). The I-joist manufacturers do not allow notching at the top end and therefore a beveled bearing plate or strip is required with web stiffeners on both sides of the I-joist. Their detail shows a strap across the tops of the I-joists tying them together across the beam, I'm pretty familiar with this detail from some local jobs I've done recently. However, I'm also wondering about the beveled strip on top of the ridge beam, how is it made, thickness at the butt etc...

With common sawn rafters how would you typically handle a dropped beam? Would you use a beveled strip or would you apply a birdsmouth cut at the ridge? I think I've seen both details but what is the preferred method if there is one.

The problem is I'm not out in the field enough so I never get to see this stuff actually go together very often.

medeek

When the plugin is loaded in a metric template it will now utilize a web dialog with metric sizes for glulam beams. The menu and glulam beam sizes are currently listed at the following link:

http://design.medeek.com/calculator/sketchup/html/web_dialog_glulam_metric.html

I probably don't list every combination possible or manufactured in each respective country or jurisdiction but hopefully I list the most common sizes. So far I have entered in data for the United Kingdom (Great Britain), South Africa, and Australia (and New Zealand).

I can enter in more countries if provided the data (width, depth, locale name and ply thickness). Now that I have the web dialogs and html files setup it is not a big deal to add more entries.

When the plugin is loaded in inches or feet then the US sizes or AWC NDS tables are loaded. So far I have only found one country that still uses the old units.

http://design.medeek.com/calculator/sketchup/html/web_dialog_glulam.html

medeek

Added dropped beam options for Gable Rafter Roof with Glulam Beam: Notched rafter and Bevelled plate.

medeek

Version 1.2.0 - 12.13.2015

Added ceiling joist option for Gable Rafter Roof.

Note: In the image shown I have raised the ceiling joist 24", the default is zero, or resting on the top plate of the wall.

medeek

With regards to outlookers and I-joist roofs I also noticed in the TJ-4000 (Detail O) they only show the outlookers in a vertical orientation. Are we allowed to do a horizontal orientation (outlookers laid flat)? And if so how do we make that attachment?

medeek

Various configurations of a cambered truss:

medeek

Things have been a little slow on the plugin development and also on visits to my plugin page the last few days as I have been busy working on some local engineering projects and have not had the time to work on any new features.

Then all of sudden this morning I noticed things were going a little wild on the site with a ton of traffic. Turns out my plugin has somehow found its way to the top of the stack on Extension Warehouse:

Not sure how it ended up there but my server has registered a serious uptick in traffic.

medeek

Version 1.2.1- 12.16.2015

Added gable end trusses (ladders) and ribbon boards to the floor truss type (Warren - System 42).
Sheathing option enabled under advanced floor options for floor trusses.

medeek

Version 1.2.2 - 12.21.2015

Added TJI Rafter Roof with Glulam Beam (all advanced options enabled).
Added dropped beam option for TJI Rafter Roof with Glulam Beam: Bevelled plate

Note, the birdsmouth cut at the lower bearing point. What I am not showing is the additional web blocking (stiffeners) required at this bearing point and at the ridge beam, see TJI-4000 for more details.

medeek

Version 1.2.2 - 12.23.2015

Structural outlookers notched around TJI top flange when oriented vertically, as per TJI manufacturer's structural details.

The tails of the TJI joists at the overhangs is left untrimmed however it is very easy to trim the tail of the rafters as shown below to customize to your particular roof requirements.

medeek

Version 1.2.3 - 12.29.2015

Added Hip Rafter Roof.

A square hip roof (pyramid):

I still need to add in the advanced options for this roof type (sheathing, fascia etc...) I'm also thinking about ceiling joists and how best to configure them. For low pitch hip roofs the ceiling joists near the hip ends will clash with the hip jack rafters unless they are oriented parallel to the jack rafters.

medeek

A more complex hip roof combined with some trusses. Note I have not trimmed back all of the rafters in the top image.

I initially generated the hip roofs (two rectangles) and then deleted the appropriate members and trimmed the common rafters to create the valley jack rafters and cripple jack rafters. The valley rafter was created by copying an instance of one of the hip rafters and moving it into place. The end result is:

Overall the process has been simplified by having the hip roof feature in the plugin. Trimming the members is the most time consuming, perhaps a more efficient trim tool can be devised so that intersecting members can be easily trimmed back to clean up a complex roof. Ultimately it would be cool to have the plugin automatically handle even more complex roofs such as this but that would take some serious programming.

Also note that I used a raised heel for the trusses so that the heel height and gutter line of the trusses matches that of the rafters.

medeek

On my Google+ page I posted some recent screenshots of the truss plugin output. One particular individual went on a rather long diatribe on the inferior nature of SketchUp as a design tool, I quote,

@unknownuser said:

"Well, if you are obsessive compulsive, sketchup is your tool. But for people who like to get projects done, there are tools that know what wood is, what lumber is, and know what the construction code is and draw in the meaningless details for you... like framing and rafters.

SketchUp doesn't know what a solid is. Doesn't do edge detection. Doesn't know what physics is. Can't self simply. Doesn't understand physical continuity. Doesn't understand region of focus. Can't deal with camera and material intersection. SketchUp has one intuitive tool, the extrusion tool, and somehow left everything else to confusion."

Some of his arguments I might agree with but it seems like the design community is starting to embrace SketchUp, at least more than I had realized. What made you as a designer or DIY'er decide to use SketchUp versus other design software?

medeek

Note the cripple or stub ceiling joists in this picture:

medeek

Testing out the hip roof feature with some more complex roof lines:

The thing that jumps out at me right away is the ease with which I can generate the basic roof lines and most of the rafters. This particular roof required (4) rectangular roofs to generate all of the lines. The only thing that is missing is the valley rafters. To make this feature more functional for complex roofs I only need to have a tool that can generate valley rafters and trim back members to create the cripple rafters.

driven

@medeek said:

What made you as a designer or DIY'er decide to use SketchUp versus other design software?

I have a vivid memory of the first time I used SU back in 2003...

Suddenly, I felt like I was out in the yard, working on the lawn under blue a sky, with the sun shining...

This simple environment was so removed from any other 'cad' dungeon I had attempted to use that it got me hooked...

then, I discovered 'FollowMe' and soon after plugins...

I went off SU during the early Google era, but was drawn back by the Fredo, Tig, Kirell, Morrisdov and other plugins of the time...

happy new year

john

medeek

I worked in the Aerospace industry for about 6 years prior to changing my focus to residential design and structural engineering. I had the unfortunate opportunity of having to use CATIA. This 3D design program feels like a dinosaur compared to anything I have ever used, and hopefully I never have to use it again. I also worked a lot with Solidworks, which I find a lot more modern and much more fun to use. I have created complete 3D residential designs using Solidworks that are fully parametric:

http://design.medeek.com/plans/planset.pl?action=GARAGE4828-A6D-3%26amp;action2=null

The big problem I had with Solidworks is the 2D drawing generation required a number of details added to the drawing sheets manually. Solidworks is very slow and heavy with manual sketches so I ended up reverting to AutoCAD which can handle very complex 2D drawings without so much as a flicker.

Lately, I have moved completely away from Solidworks as a design tool because of the time it takes to generate models and also AutoCAD is where I end up when it comes generating the drawing set. However, a 3D model is always nice to have for ISO views and other reasons. I've briefly played with Chief Architect as a Solidworks replacement but I find it too limiting and I was not overly impressed.

The one thing I really like about SketchUp is I can pass the model on to the client and they can quickly download and install the program (lightweight) and be up and running almost instantly. I wish the software had a few more tools built in like a mirror function etc... but overall it is a pretty good package especially when you consider that you can just download it for free and most plugins are relatively inexpensive.

The big architectural firms typically use products like Revit, but the casual user and smaller design firms don't have that amount of budget to dump into software.