Its from Google.
Its free.
It is called SketchUp.

And Clark has written some cool utilities when you want to 3D model complete joinery and generate shop drawings... and label your parts, export lists to drop into Excel spreadsheets for estimating...

The only function it lacks is to help me lose 20 pounds and get faster on the bike.

KP = King Post, typically a solo post centered in a truss that runs to a ridge or the peak, usually ending at a tie or lower chord

QP = Queen Posts, usually paired posts dividing a truss span, both running to either principle purlins or to principle truss rafters.

This glossary first appeared in TIMBER FRAMING 68, June 2003.
Glossary of Terms.pdf

Thanks guys,
I have the glossary now and I'm downloading the program.
I liked the proposed design that was posted, however, it looks like it will take 6 24' beams to construct it... while I have standing trees where I can get the 24 footers, I'd rather put this little project together with logs that I already have down, which limits me to three 24 footers... I may have to put that center post in unless I can design a way to attach the three bents together with two 12 footers instead of one 24 footer...
Maybe after I get the SketchUp downloaded I'll play around with a couple of designs.

My plan was to cut 8x8 beams for the posts and rafters and 8x10 beams for horizontal members (braces probably 6x6) all out of green SYP.

Anyone have any comments about that?

I just noticed in B-mikes last sketch up that the tie seem very close to the top plate, perhaps it should be dropped 6" or so at a minimum. What does the joinery look like there, Mike?

6x6 braces? 4x6 is a more standard size, allowing a simplified mortice and tenon.

I only see where you need 5-24'ers, so you only need two more, it would be well worth the taking down of two more trees for the top plates. Skip the bloody ridge.

Tim

Braces were drawn as 4x6 but I'd make em 3x6 or 7 depending on what tools I have to cut mortises.

Scarf joints to get the longer stuff. Skip the 'bloody' ridge if you are comfy with your loading - but as I mentioned it will really stiffen the structure as you are building a lattice for sheathing and have no shear in the roof planes. And if you lose the ridge lose the kp's and braces and struts too.

You could also build a center bent and spline the top plates and ridge through the posts to use shorter material.

And sure - you can drop the tie on the posts 6-8-12 - but you'll have a shearing problem if you lose the ridge - the rafters will push out on the top plates which will want to tear the tops of the posts off - the more you drop - the bigger lever you have to do this. And make sure your joinery @ the post / plate is designed to resist the plate rolling as the rafters push out. I think a small drop is acceptable and if I spent more time on free design I probably would have corrected it when I started to design the joinery.

But - you live in the magical land of little to no snow - so figure out what works best for you.

Timber Frame Construction, has a nice solution, IMO, on how to address this issue on page 170. I would recommend this book to anyone.

You could loose the kings, braces and struts but then you wouldn't have much. The vast majority of historic barns I have in my area have no ridge beam or even ridge board, the rafters are butt cut and spiked, working just fine. They all have bracing.

I understand what the struts are doing, but dropping the king seem odd. I am struggling to understand this. Are there examples of trusses with out kings, only the struts? How does this work? Especially in the future when a floor load is applied.

Tim

Tim - why build a truss if it is not going to supprt the roof? Just to hold up the tie? You've suggested ditching the ridge - in which case if you are not using a principle rafter or purlin system and there is no loft you could just as easily control the tension with a very minimal tie.

I'm sure barns without a ridge or purlins or ridgeboard exist. Every barn that I've surveyed (PA, MD, NJ, and OH) has either.

Have you set rafter pairs that were butted and spiked for a 24' span? I'm curious how that goes. (Serious question, as I think the ridge (or purlins) add an ease of assembly function as well as rigidity and bracing.

So - ditch all the timberwork in the roof system. Stick frame it. Design the tie to post connection to take the outward thrust. Hope that the metal roof and latticework offers enough bracing in an open structure against the wind.

Could work just fine. The OP will need to do his homework. In my neighborhood - I wouldn't do it the way you propose. And the OP is seeking to timberframe after all...

Hi Tim,

The way I saw it there were three ties side to side(24'), two ties(?) front to back (24'), and then the ridge (24')... six total.

4x6 is no problem... since they are going into an 8x8 can I just cut a 4" mortise and put the whole piece in without cutting a tenon?

Ben

Ben - study up on how you will want to do the layout (differing systems) and how a brace works. You'll most likely do a housing and tenon. On 4x material this will usually be 2" and 2". If you have capacity to easily cut 2" mortises (the tenon is the easy part) then go for it. For me, I'd either be drilling and cleaning up or running a chain mortiser. Both tools that I have access to are more efficient @ 1.5" - so personally I'd design my joinery for the loads I anticipate and the tools I have at my disposal. YMMV (your mileage may vary)