Relatively Painless 3D Modeling of A Potentially Troublesome Unistringer

[Dadgad]

An architect friend, asked my assistance in modeling and creating fabrication drawings for a rather daunting unistringer to be made of HEB180 profile, which had been giving her trouble. I was happy to help, but I had some trepidations, as there are a few unorthodox angles evident in plan view. I was very pleasantly surprised to see how well the Sweep command handled this task. Had I needed to use the Extrude or PressPull & Subtract commands and manually align all of these bits, it wouldn't have been much fun. Pretty well defining the concept of, on the far side of Tedium.

 

I started by defining the sweep path as the intended center of the top flange of the HEB180 specified, with a continuous 3D Polyline. Having chosen an isometric view and set the UCS to World, I accessed my closed polyline of the profile and put it into modelspace. There is no need to manually orient the Object to be swept into position on the Path which will be used for the sweep command, the software will take care of that.

I started the Sweep command, defined the Basepoint as the top center of the profile (because sometimes the software guesses wrong), and picked the PATH. Lo & Behold, it worked perfectly, you could have bowled me over with a feather! I was surprised to find that I did not need to specify the Alignment, as square to the path is the default. On a subsequent repeat without specifying the Basepoint, exactly the same, no problem. Just pick and click would have done it, without any user input. Should you experience a less than satisfactory result without specifying, then Undo and try again with a specified Basepoint.

 

The 3D Solid generated was a single piece, which would have been very difficult to document assembled. Using the Slice command with the 3Point option, in non Orthogonal views, it only took a couple of minutes more to cut it into the subparts, ready for me to Solprof for fabrication dwgs. The keys are creating an unbroken PATH, so that the model to angle bisector function will be called into play by the program; setting your UCS to World and using a CLOSED polyline if you are interested in creating a 3D Solid. In this case, that meant I needed to use a closed polyline for the object profile and a 3D Polyline to accomodate the elevation changes for my path. :wink:

 

After slicing and dicing the 3D Solid stringer into the individual parts, I added the structural members to which it will attach, and the mating bits were coped into them with the Subtract command.

 

I was quite pleased to not have to wrangle all those seemingly random bits, it clearly would have taken longer than the five minutes required to do it this way.

It is always gratifying when something works much better than anticipated!

Edited April 17, 2015 by Dadgad

[ReMark]

Interesting. Thanks for the dissertation. May prove helpful to others.

[CaddJax]

Funny thing happened to me last night.....

 

I was modeling an auditorium wall for an acoustical client last night. This wall is angled in both plan & section with a taper along the z-axis. I spent the better part of an hour trying to piece this ******* together, then I remembered the sweep command as well, lol. In less than 5 more minutes, I had my wall modeled and inserted. I felt kind of stupid at the moment, but when you learn something the hard way, it will come to mind a little quicker next time. Glad you figured it out as well.

[BIGAL]

Dadgad a support for a set of stairs ??

[Dadgad]

Dadgad a support for a set of stairs ??

 

Yeah, BIGAL, a single beam stringer for stairs to the 3rd floor, with

2 pairs of winder treads and only one right angle in the whole thing.

Edited July 24, 2014 by Dadgad

[lamensterms]

Hi Dadgad,

 

Interesting geometry you've got there. Are you a steel detailer? Just wondering if you have used ProSteel?

[Dadgad]

Yes, for the most part, and very funny that you should ask about ProSteel.

I started using & learning ProSteel V8 (the Autocad version) about 6 weeks ago,

and took basic instruction for modeling and detailing (5 days) in the middle of February.

 

I see from your profile that you have experience with ProSteel, how do you like it?

Words of wisom for a newbie?

[lamensterms]

Ah cool. I've been using it for 4-5 years now, and it is capable of delivering great results & equally great headaches. I must admit I am a fan of it though. It is very flexible and once you get into a groove, it can be really easy to use.

 

Haha, probably the best advice I can give you is to save frequently. The most annoying aspect of ProSteel is that it can crash (sometimes often).

 

I'd be happy to help you with any questions/queries you may have. The Bentley forums are quite good, as well as the ProSteel OZ forums.

 

How are you finding it so far?

[Dadgad]

I am impressed by the way it can spit out drawings, but a bit concerned about giving up the reins to the software.

 

While I was taking the instruction, it kept crashing, which was quite annoying,

as it had me playing catch up a lot of the time.

 

Now that I am at home, it hasn't crashed once.

 

I have been recreating our Standard items catalog in ProSteel, thus far.

Most of it is pretty easy, but occasionally I get stumped by things that would be really easy in Autocad.

We haven't done our first job with it yet, although we are starting to mock up one which we have tendered,

to get used to using it. I look forward to being more comfortable with it, probably by about our 3rd or 4th project

we will know how we want to use it, and our template structures will be starting to come together.

I will have to sign up on the forums you mentioned, thanks for the suggestions, and offer of help, greatly appreciated.

 

Do you ever use the ACIS Reference feature of the software, if so when might you do so?

[lamensterms]

You're welcome Dadgad, feel free to hit me up any time (no question too small).

 

I have never used ACIS Reference (do you mean PS_SOLIDREFERENCE?). I have never had the need. Whenever possible, I try to model all components (that are to be shown on shop drawings) as genuine ProSteel elements. I really only use ACIS or ASM solids for non-steel features (slabs, walls, etc). If I do ever need to attach ProSteel data to an ACAD solid, I use the PS_CREATE_SPEZPART command. Keep in mind though, the 2D Display Mode feature will not work for ACAD solids that have had the PS_CREATE_SPEZPART treatment. Also, these ACAD elements with ProSteel data cannot be seen by the 2D Detail Center (while PS_SOLIDREFERENCE solids can).

 

If I'm trying to create complex geometry that cannot be easily represented as by standard ProSteel elements, I use the boolean functions. As a rule of thumb, I only ever boolean ACIS solids to ProSteel elements - this will ensure that the element can be converted to ACIS (for NavisWorks clash detect/FLATSHOT/etc). For example, I have attached a handrail stanchion - this began life as a genuine ProSteel element (a blank of sorts), and has had an ACIS mould subtracted from it.

 

Special parts created this way have all the benefits of genuine ProSteel parts, but must always be displayed in 'Solid Kernel' mode.

 

Wow - that turned out to be quite the spiel.

 

Stanchion.dwg

[Dadgad]

Thanks very much for taking the time to do that, very enlightening!

I too am just creating everything from scratch in ProSteel, so that all of the functionality is intact.

 

Now get back to WORK!