Wednesday, 21 December 2016

Punch iFeatures

You have no excuse!

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”


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