Punch iFeatures

You have no excuse!

iLondon

I will explain this one again and you will no longer have an excuse.

 You will have to force yourself and use it but trust me it will save a lot of time and increase your productivity.

I’ve seen this one too many and it’s killing your productivity and possibly your enthusiasm on using features, especially punch features.

First of all what are iFeatures?

Autodesk dictionary helps us out:

“Converts a single feature or a collection of features into a feature you can reuse in other part files.”

The definition is a bit circular, I agree. What that means is that if you model the same things everyday (keyways, for example) then you better make those an iFeature and reuse them.

Furthermore the iFeatures can have a table and you can generate custom sizes from easy to use forms with drop down menus and you can even have custom prompted values, with range and increment.

You will get a new file type "ide" but you can even drag-drop it from windows explorer.

I use them all the time and I have all sorts of ifeatures like flanges, ferrules, pipes, but especially features for my tanks and vessels, like manholes-manways, spray balls, feet, ladder attachments, lifting trunions, on and on...

One essential rule is to have the feature self-contained and do not reference any other geometry. If you do need to make it depended then only reference features to be included in the ifeature element.

 A special case are the Punch iFeatures for which the first element needs to be a sketch with a work point; this will be used as the insertion point and is especially helpful with recurring patterns.

We are here because you spent a lot of hours planning ahead, tested your ifeatures and perfecting the technique of making them independent and yet they fail to work. The work feature is not normal to the face and you have punches that are not protruding the sheet metal part.

And that is because your work is too perfect! That’s right, you need to take a step back, don’t make it quite that independent and reference the sheet face.

Typical procedure is to create a sketch and place a work point on it. Then create a construction line trough the point and finish the sketch.

Now you have the insertion point for your punch ifeature. You then create a work plane where you model the sketch of the punch.

The wrong way to do it is to create the workplane from the sketch workpoint and the sketch construction axis. At this point the ifeature will have no reference to the sheet face and it will spin in space as it sees fit.

Wrong way of doing it:

Wrong way of doing it

Correct way of doing it by referencing the construction line and the face where the sketch is defined.

Correct way of doing it

Don’t worry the face has been referenced before when you created the insertion point so you'll still have only one reference to pick when placing this.

Wrong way of doing it, end result:

Wrong way - wrong results

Correct way of doing it, end result:

Correct way - correct results

Repeat after me:
“I will use ifeatures from now on, save time and increase productivity”

 Later,

ADS

photo credit: @Doug88888 London - Light painting London (license)

Butt Fusion Fittings

Still buried with work and not sure if I’ll be able to do a video but at least you will have some quick info on how to do but fusion fittings and routes in general.

Depending on the complexity and detail you need there are a couple of approaches to take here. The simplest one would be to ignore the discrepancies before and after the pipe welding but you can take it all the way and create your excess welding material as ifeatures that you can drop on each fitting you author.

On my plant layouts I always ignore them because we tend to have plenty of space and discrepancies can be ignored. Quite simply on a 10 meter pipe the assemble tolerance will incorporate any variation from welding or thermal expansion.

So unless you’re into designing medical equipment or any other precise, tight tolerances equipment I would not bother. Keep this as a reference if every once in while you need to do renderings, or the client asks for these welds to be in place and ignore them the rest of the time.

On the simple side, quick and dirty if you do need to have proper, exact cut-to-length dimensions and BOM reports then you need to over-define your engagement dimensions so that the parts interfere therefore reporting correct pipe length and correct route dimensions, node to node.

If you do need to get all that detail exact and you have all the time in the world I would suggest you do the fusion as a ifeature that you can drop on each fitting. Make that ifeature table driven so you can choose and change size on the fly. You can take it down another level and calculate the lost volume from the cutout (melting) and generate your weld bead based on that but that’s way too granular for me.

If you need to author ipart fittings like elbows, tees, or anything else that has a table and might go to Content Center then define new planes driven by the fusion distance and set your engagement to plane/point so you can drive the engagement for each fitting diameter separately.

I recommend that you don’t change or re-author the pipe because you might use that pipe on different connection style (socket welding, jointed, etc.) and it will mess those up. Do all these changes on fittings and it will drive the pipe engagement as well.

Don’t just stop here use the over-engagement on compressed gaskets (thank you Chris Benner for the solution), expansion joints etc.
Here are a couple of links on Fusion Welding, general info and dimensions to help you on the process:
-          Local Head Loss in Polypropylene andPolyethylene Pipeline Joint Welded by Butt Fusion - Ing. Jaroslav VeselskýSupervisor & Prof. Ing. Jan Melichar, CSc.
-          Polyethylene Pipeline Systems - Avoiding ThePitfalls of Fusion Welding - Dr Chris O’Connor

And the post on Autodesk forum that generated this idea.

I have managed to do a video for my youtube friends. Not my best of works, you can hear I am tired and out of focus, apologies for that.

Later,

ADS.