3D Truss Models

medeek · 5 Nov 2015, 16:45

I thought about multi-ply girder trusses but I think for now it is not too hard for the user to simply create another instance of the truss component and manually stack them up to create double or triple ply trusses.

Another interesting thought I had is what would it take to codify an algorithm for creating a typical dormer:

However, this may be a bit ambitious at this point but I think it could be done.

medeek · 5 Nov 2015, 16:49

In my neck of the woods we don't typically use dimensional lumber alot for floor framing anymore. Most of what I see is I-Joist products with LVL or LSL rimboard.

For those that still use dimensional lumber what is the common practice for the rim joists? I'm assuming that it is the same as the rest of the joists in the floor (ie. 2x8, 2x10 or 2x12).

pbacot · 5 Nov 2015, 17:02

We use both--particularly for the first floor over a crawl space, lumber can be economical. The rim joist is the same.

medeek · 6 Nov 2015, 06:57

Version 1.0.9 - 11.05.2015

Added separate toolbar icons for floor trusses and joists.
Created separate submenu items under the Medeek Truss Plugin Extension for roof and floor trusses.

The main menu was getting a bit cluttered and not so user friendly so I split it out into "Roof" and "Floor", hopefully this makes more sense.

medeek · 6 Nov 2015, 08:51

As I've been contemplating adding gambrel attic trusses to the truss plugin I've had to give some thought to what constitutes a good gambrel design. I've looked into this before but my conclusion is that no matter the lower and upper pitch of the roof a good looking design seems to be always achievable if the lower and upper legs of the roof are more or less equal in the length. To that end I've devised a simple spreadsheet calculator that will quickly throw out the numbers and display a graphic of the gambrel profile:

I'm not saying this is a hard and fast rule but it seems to give decent results. Minor variations (ie. L1 not equal to L2) are generally okay but if one leg is significantly longer than the other the gambrel profile becomes distorted.

The math to come up with this equality and generate the coordinates of the overall roof height and the pitch break is rather interesting and for those mathematically inclined is given below. Note that the equation ends up being a quadratic equation with the positive root extraneous:

medeek · 7 Nov 2015, 02:05

I'm working on the advanced options for roof trusses and I'm looking at the fascia board. I've come up with three different configurations for the fascia that I've seen in practice and in the architectural books that I have.

Which method of the three below do you prefer? or is there another configuration that I have missed?

Note that I am only interested in the sub fascia if there are additional trim boards that is up to the architect or designer.

Krisidious · 7 Nov 2015, 10:44

I prefer 1 and 2

I would take it a bit further or leave it simple, those that want more detail can use a number of paid plugins or free ones to route fascia profiles. but for doing fascia those plugins don't take in to account the subtleties of "following" a fascia path. certain sides and corners and what not are done quite differently with the same styling.

But one of my most common fascia combos ranges from 1x8 with a 1x4 added to it's face or I might even taller up to 10" or maybe 12" with 6 or 8" facing it.

up to you... you've already created quite a product.

medeek · 7 Nov 2015, 11:15

I think I will include the option for either of the 3 variants since it isn't too much more to code and I'm getting quite a mixed reaction from different builders and designers. I guess everyone has there preferred method.

Another quite common fascia treatment is to use a 2x6 sub fascia with a 1x8 finish fascia (primed spruce or cedar).

However, I am mostly interested in the sub fascia and then I'll leave it up to the designer/architect to dress it up further as needed.

I'm trying to make the roof framing as easy as possible and basic structural items such as trusses, fascia, outlookers are all automated, then the designer can concentrate on the finish work (ie. ridge caps, trim fascia, barge boards, cupolas).

medeek · 7 Nov 2015, 11:19

I've noticed that the admins have moved this board to a new location. Along that same line of thinking perhaps it is not appropriate that I discuss the day-to-day development of this plugin in the forums. I'm not entirely sure of the protocol on this since this is new territory for me. I will probably continue to field questions on this board related to the posts made thus far but if you would like to closely follow the development of this plugin please email or PM me.

KrisM · 7 Nov 2015, 18:00

I for one welcome seeing your comments re the plugin development and wouldn't want you to put this behind closed doors so to speak. Was the topic originally in the general forum and so has been moved more appropriately into the plugin area? Keeo it coming.
KrisM

medeek · 7 Nov 2015, 21:31

I would like the freedom to post links to other forums or resources as I see fit and this may not fall in line with the terms of service of this forums and others. I will not be bringing the development and its discussion behind closed doors, just to separate venue that I can have more control over and not be limited in the direction I may want to take the conversation.

I will continue to post major updates to this thread until someone tells me otherwise but for the daily development I will posting to my own personal blog or forum.

medeek · 7 Nov 2015, 21:34

@krism said:

I for one welcome seeing your comments re the plugin development and wouldn't want you to put this behind closed doors so to speak. Was the topic originally in the general forum and so has been moved more appropriately into the plugin area? Keeo it coming.
KrisM

On a different note I notice you do timber framing up in Salmon Arm, somewhat in my neck of the woods. What plugins specifically do you use regarding your trade or are there tools that support the timber framing trade.

I would be interested in working on some plugins that deal specifically with timber framing, hammer beam design, bents etc...

pbacot · 7 Nov 2015, 23:40

I don't thnk there's anything wrong with this thread. Great to follow it. Eventually like other plugins, this thread (or another) can be where people share their thoughts and questions on the plugin.

medeek · 8 Nov 2015, 16:23

Version 1.1.0 - 11.08.2015
Added advanced roof options for Common, Scissor and Attic truss types.
Sheathing option enabled under advanced roof options.
Rake Board option enabled under advanced roof options.
Fascia (Flush, Dropped, Beveled) option enabled under advanced roof options.

medeek · 9 Nov 2015, 01:17

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.

medeek · 9 Nov 2015, 01:18

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.

medeek · 9 Nov 2015, 03:11

I should be working on my regular work but SketchUp has an addictive hold on me at the moment. Trying to do a bit more complex roof line below. Immediately some things that pop out are the inherent complexities that occur when roof lines meet. The question is how to setup the plugin to automatically handle these situations, this will not be easy. I was able to easily trim and delete unnecessary rake and fascia boards as required. The trusses themselves need to be more dynamic so that one can adjust the overhang to zero as required. It is easy to select a number of component instances and make them unique and then adjust as required. In the second image I've copied an instance of the queen post truss to create a girder analog.

The other thing that needs some attention is the ability to easily create a valley set that frames over the larger roof line. I've got some ideas on this one, its going to take some interesting math but its not impossible.

Also notice how I have used a howe, fink and queen post truss to demonstrate the use of all three truss types.

The other interesting point is that when you specify the fascia boards it is quickly apparent whether or not the heel heights match up and everything is correct.

pbacot · 9 Nov 2015, 03:50

That's awesome. The accuracy is something anyone can appreciate if you are doing house models for real full house construction projects.

Personally framing has only been a small special part of my modeling, but if that's where you want to go with it, this is really impressive in terms of building knowledge and ruby coding.

medeek · 9 Nov 2015, 06:46

I've got this far and the code is still less than 1 Mb, there is a lot more that is possible. Take a look at the typical output from Mitek's Sapphire program. This is the level it needs to get to in order for it to be useful.

Valley sets
Hip sets
Transition trusses
Girder trusses
Gable end trusses

juju · 9 Nov 2015, 09:35

this plugin is evolving to the extent where a short user manual will be useful