medeek Posted October 3, 2015 Report Posted October 3, 2015 Its been a while since I've posted on this board. I am still plugging away at the truss calculator that I started back in 2013. Under "Advanced Options" you can now specify the lumber species, grade and size for the top chord, bottom chord and webs, this should allow one to check any fink truss "as built". I still have not configured a method to specify the plate sizes at each joint but that should not actually be that difficult. For now the plate are auto sized until the JSI requirement is met. This is probably the most significant update to date since it allows one to "check" a truss versus "design" one. Another cool feature I added last night is the ability to generate 3D models within Google SketchUp. In order to do this I added SketchUp 3D (.rb) file output for the truss geometry. This file, when copied into the SketchUp plugins folder, will create a menu item within SketchUp allowing for unlimited creation of the given truss geometry within SketchUp. I think this feature will be particularly interesting to those DIYers who wants to draw up their own model and plans using SketchUp. The plugin allows for user input in order to specify number of trusses and spacing of the trusses. For example 4 trusses @ 24" o/c would give you: The number of updates and new features has become rather lengthy so I created a changelog page to keep track of all this: http://design.medeek.com/calculator/changelog.html Earlier this summer the server was getting hammered so I implemented a daily limit however the calculator is still free to use. Another challenging update was the introduction of point loads under the advanced loading tab. This feature will probably be useful to contractors and homeowners interested in solar panel installations.
Jim Katen Posted October 3, 2015 Report Posted October 3, 2015 Very cool. Any chance you'll eventually have a calculator for scissor trusses?
medeek Posted October 17, 2015 Author Report Posted October 17, 2015 Very cool. Any chance you'll eventually have a calculator for scissor trusses? It is in my "to do" list but at the moment I'm a bit sidetracked with a SketchUp plugin that allows one to create truss geometry (without the engineering). After creating the SketchUp output in the Truss Designer I had a number of requests from residential designers who wanted an actual plugin/extension that worked independently from my website and would allow the creation of the geometry within SketchUp. Here is a link for those interested in beta-testing the new plugin, its still a work in progress but its progressing rather rapidly since geometry is a lot easier to deal with than all of the engineering calcs: http://design.medeek.com/resources/mede ... lugin.html Note, that the trial version is currently not limited in any way. At some point when the product is substantial enough to warrant charging for it I will probably introduce some limits to the trial version. I'm currently working on fine tuning the attic truss option within this plugin. Here is a 28' attic truss I used on one of my own garage plans: I still need to develop the algorithm for raised heels as applied to this truss type and also better logic for span ranges between 16-24' and 30-36'.
medeek Posted October 24, 2015 Author Report Posted October 24, 2015 Very cool. Any chance you'll eventually have a calculator for scissor trusses? I still need to create the calculations for a scissor truss but it is now available in the truss plugin (geometry only).
Marc Posted October 24, 2015 Report Posted October 24, 2015 Going off course here for a sec...Do you see any response from the truss industry regarding the recent discovery that metal gussets pop off under condition of fire? Roof/ceiling assemblies and floors collapse much earlier and firewalls lose integrity. The fire spreads much more quickly, giving firetrucks less time to arrive and folks less time to get out. I heard NJ was considering outlawing trusses in some types of constructions. Marc
Jim Katen Posted October 25, 2015 Report Posted October 25, 2015 Going off course here for a sec...Do you see any response from the truss industry regarding the recent discovery that metal gussets pop off under condition of fire? Roof/ceiling assemblies and floors collapse much earlier and firewalls lose integrity. The fire spreads much more quickly, giving firetrucks less time to arrive and folks less time to get out. I heard NJ was considering outlawing trusses in some types of constructions. Marc Instead of outlawing trusses, they should inlaw fire suppression systems.
Erby Posted October 26, 2015 Report Posted October 26, 2015 It's slowly headed that way, Jim. http://ircfiresprinkler.org/wordpress/s ... uirements/
medeek Posted October 26, 2015 Author Report Posted October 26, 2015 Version 1.0.6 - 10.25.2015 Added floor truss type, Modified Warren - System 42. Metric input enabled for floor truss types. Top and bottom bearing option enabled for left and/or right end of floor trusses. Ribbon cut option (top) enabled for left and/or right end of floor trusses. One central chase that can be position relative to the left end of the truss. If the chase becomes closer than 1/4 the span to either end it will flag the user and re-position. Also some logic to check the chase size to span ratio and absolute max. chase size (24"). System 42 or 32 floor trusses using the modified warren configuration which seems to be the most popular for this type of floor truss. Top bearing configuration includes an additional slider for extra strength and a vert. Note the change in diagonal directions when comparing a top to bottom bearing floor truss, I was not aware of this until studying them in some detail. Typical panel length is 28" but this can also be set by the user to any value.
medeek Posted October 26, 2015 Author Report Posted October 26, 2015 Going off course here for a sec...Do you see any response from the truss industry regarding the recent discovery that metal gussets pop off under condition of fire? Roof/ceiling assemblies and floors collapse much earlier and firewalls lose integrity. The fire spreads much more quickly, giving firetrucks less time to arrive and folks less time to get out. I heard NJ was considering outlawing trusses in some types of constructions. Marc I have not heard or read anything but that doesn't mean there might not be some movement in this direction. Bowstring trusses have a particularly bad rap when it comes to collapses and fire. Steel is an excellent conductor and has no charring mechanism like wood (specifically large timbers). I'm going to have to do some reading on this, sounds interesting.
medeek Posted October 27, 2015 Author Report Posted October 27, 2015 Just out of sheer awe I have to post these two pictures I found at Select Trusses website: My one worry with commercial buildings constructed using light frame construction is fire resistance. This building wouldn't have a chance if a fire were to occur: A quad fink truss (10/9) with a raised heel (slider):
medeek Posted October 27, 2015 Author Report Posted October 27, 2015 Various configurations of dual pitch trusses:
kurt Posted October 27, 2015 Report Posted October 27, 2015 This is remarkable. I especially like the fact you've adopted SketchUp file output.
medeek Posted October 29, 2015 Author Report Posted October 29, 2015 I've got gable end trusses working for king post trusses: I haven't made this latest update live just yet as I need to update all of the other truss types to make sure it does not break anything. The other thing I am changing is the second user prompt box that allows one to enter in the number of trusses. I have now switched to a building length and the logic spaces the trusses based on the this length and the truss on center spacing. Gable end trusses can be switch on or off. Spacing of the gable studs is another user input.
medeek Posted October 29, 2015 Author Report Posted October 29, 2015 Various configurations of a vaulted or cathedral truss: This and the dual pitch trusses will be added next, then its on to Gambrel Attic trusses which will be a real challenge.
medeek Posted November 9, 2015 Author Report Posted November 9, 2015 Just playing around with SketchUp a bit today and trying out the new sheathing, rakeboard and fascia capabilities in the Plugin. The roof of this simple structure took all of 10 seconds to create, the rest about 20 minutes. I didn't realize Simpson Strongtie hardware is available in the 3D warehouse, good to know. I'm not going to say anything about lateral bracing of this structure, just modeling for fun. One can go so far as to put all of the H1 ties in. I could waste an entire day messing around in this software, way too much fun.
Marc Posted November 9, 2015 Report Posted November 9, 2015 Do you mean that I could (except for the lateral bracing) use this thing to design an addition to my workshop? Marc
kurt Posted November 9, 2015 Report Posted November 9, 2015 Sure. SketchUp is the most amazing piece of free software there is. 25 years ago, the software would have cost about $25K and it would need to run on a $20KSun Workstation. Now, it's a free download @ http://www.sketchup.com/
medeek Posted November 15, 2015 Author Report Posted November 15, 2015 Do you mean that I could (except for the lateral bracing) use this thing to design an addition to my workshop? Marc That's the idea at least. Most people end up paying a designer in the end if they are not familiar with the building codes but I'm amazed at some of the "almost complete" designs that land on my desk these days. Still a long ways to go to complete this plugin but I keep chipping away at it in my spare time: Version 1.1.1 - 11.14.2015 - Gable end trusses enabled for all monopitch truss types. - Added energy/raised heels for monopitch trusses (3 variants: wedge, slider and vertical w/ strut). Currently there are only two versions of the monopitch truss available (2/2 and 3/3). The truss set below shows a monopitch truss set with gable ends and a 36" raised heel.
medeek Posted November 23, 2015 Author Report Posted November 23, 2015 Outlookers enabled under advanced roof options for Common, Scissor and Attic truss types. Not really sure what is the best treatment of the outlookers at the peak of the roof and consequently what is best way to space them. Measure them from the peak or the eave/fascia? One thing worth noting here is that structural outlookers are also enabled but I have not yet coded in the dropped top chord gable end trusses that would match structural outlookers, something for another day. Due to the option of vertically or horizontally oriented outlookers the configuration of a dropped top chord gable end truss can take two configurations. For attic trusses this gets even more complicated at the gable end, hence I haven't even attempted the gable end truss option for attic truss types yet.
medeek Posted November 23, 2015 Author Report Posted November 23, 2015 A dropped top chord with flat orientation might look something like this: Without an overhang the gable end truss becomes: Note that the outlookers would probably be spaced from the bottom at 24" on center.
Jim Katen Posted November 23, 2015 Report Posted November 23, 2015 Hah! Don't bother with the dropped chord. We'll just notch it. . .
medeek Posted November 26, 2015 Author Report Posted November 26, 2015 Version 1.1.5 - 11.25.2015 - Added Double Fink common truss type. - Structural outlookers (vert. & horz.) enabled under advanced roof options for Common (Double Fink) truss type.
medeek Posted November 26, 2015 Author Report Posted November 26, 2015 Hah! Don't bother with the dropped chord. We'll just notch it. . . Every truss document I've ever seen always forbids notching the truss even though I would agree that a typical gable end truss is non-structural and notching of the top chord should be a non-issue. A few of the contractors I work with will usually order the dropped top chord gable end trusses but when its missed they will usually notch the gable end trusses. They say they've never been called out by the inspector on this.
Jim Katen Posted November 26, 2015 Report Posted November 26, 2015 Hah! Don't both with the dropped chord. We'll just notch it. . . Every truss document I've ever seen always forbids notching the truss even though I would agree that a typical gable end truss is non-structural and notching of the top chord should be a non-issue. A few of the contractors I work with will usually order the dropped top chord gable end trusses but when its missed they will usually notch the gable end trusses. They say they've never been called out by the inspector on this. From a strictly technical point of view, a gable-end truss isn't a truss at all. It's just some prefab wall framing.
medeek Posted November 27, 2015 Author Report Posted November 27, 2015 Version 1.1.6 - 11.26.2015 - Added Fan and Mod Queen common truss types. - Structural outlookers (vert. & horz.) enabled under advanced roof options for Common (Fan & Mod Queen) truss types. Four more common truss types still need to be added: - Double Howe (6/6) - Mod Fan (8/4) - Triple Fink (8/7) - Triple Howe (8/8) For very large buildings one could also consider: - Quad Fan (10/5) - Quad Fink (10/9) - Quad Howe (10/10) - Quin Fan (12/6) ... A quad fink truss (10/9) with a raised heel (slider):
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