Stiffeners

[Haha]

See!!

[cadbob]

See!!

Hi Ha, (that sounds funny)

It works fine with a single pressure file, but with multiple specs is where the problem arises.
The way to get CADduct to do it with all the pressure classes and the different size/break points for each pressure class it would require us to have Tie-Rods and Angles for each pressure file or a few anyway.

 Like for instance if the 96" side required a Mid-Panel  along with Tie-Rods with 6" wg but on 2" required 3 centers and a joint.

 Yes there are work around's as i said in 1st paragraph, but the correct fix or easiest would be to have 2 stiffeners; one on Long Side and one on short side per spec. Well i'm not really sure that would be correct, but Andy does know about the issue.

 So when you go into stiffener A External and set the break points for it with Tie-Rods and 2"wg needs A at a certain size but the break points are for 4"wg. So one would need A-2"wg and A-4"wg set in your specs.

[Haha]

Thats exactly what we did and it works perfectly!!!

[cadbob]

So on on example of 96x48 duct the stiffener would be as follows;

96" would have 2-1/2"x1/4" Angle Mid-Point with EMT Both Joints and Mid-Point
48" would have 1x1x1/8" with EMT at Center and Joint

These are just fictitious Specs but trying to get Idea across. Anyone viewing needs latest Design Review 2012 for best results. If you look at ITEM TAKEOFF screen capture you will see where STIFFENER #2 needs to be for true LS/SS

There is noway to do it.

[rptjr]

Okay – In my attempt to figure this out I have found many many many threads on stiffeners. This seemed like the most appropriate thread but you may be able to point me in another direction. Been working this for awhile and kinda getting sick of it!

Like Tryle I have my specs setup with lengths as well but unlike Tryle I have my specs as ls/ss. I have setup individual stiffeners based on what is required per my ls/ss spec. For example I have one called MPT (one single tie rod at the mid point). I have the appropriate quantities of 1 listed and then have specified the rod type and bolts. The size breakpoints are listed at 999 for both my span and lenght. I then apply this stiffener MPT to the appropriate ls/ss size in my spec with spacing of 30”. When report on the ancillaries for a 5’ pc that uses that stiffener I get 2 ties rods and 4 bolts instead of 1 tie rod and 2 bolts.
After reading Tryle’s setup I tested that setup with my ls/ss spec and I still get quantities of 2 and 4 instead of 1 and 2.

Im just not getting it. Is this another result of LS/SS not available with stiffeners?

[cadbob]

See attached they change by size and length

[rptjr]

I believe I have this working - creating multiple stiffener specs per wg and lenght. Some overlap but its easier to just create them all than try to figure what can be used twice.
Anyway - overall my issue was with breakpoints and not understanding what the dif was between span and length.
Thanks.

[cnash]

I know this is quite old but is this still the method everyone is using for their stiffener setup?

[cadbob]

I haven't changed my stiffener setup Chris. Been so long think I forgot how I did it! LOL

[cnash]

I haven't changed my stiffener setup Chris. Been so long think I forgot how I did it! LOL

Haha, I understand that.
I am currently going through and completely overhauling all of our ductwork. As I was doing so I realized there were some things we overlooked since we weren't too concerned with some of the items at the time. Now I am trying to make sure it's all actually right and it's causing a few bouts of headaches and heartburn.