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Top Down Design & advanced assembly


New member
Plz advanced user advice only.

I have been using Top down design for a few years now. The problem I keep having is that patterned holes are a pain. I have 6 different parts all with 180 holes at the same dia butdifferent sizes and shapes. Some of the parts are the same just flipped over or used more then once.

What are my options. I want to control allparts from the skel and minimize the number of features in each part.

If you don't have a very good understanding of top down design plz only post back with proved out examples.


New member
I understand your pain Heatbn.Unfortunatly PTC developers cannot grasp the importance of this issue.If you create say datum point pattern representing the position of the holes in the skeleton and copy it via copy geometry into parts ProE cannot recognize this as an existing pattern and therefore a reference pattern cannot be used.

However there is work around.Create the positionong pattern in the skeleton.When in the assy modify one of your part crezting first hole by referencenig first positioning feature in the skeleton and than use a reference pattern for the rest.Repeat this with the rest of the parts.You can define the shape definition in the skeleton as well.This is,of course,is notproper top-down design and you will have external references not only to the skeleton but to the assembly as well.Nevertheless this is the best way I found so far for the cases like yours


New member
Another way may be use of a ineritance feature.Inheritance feature unlike skeletons will recognize a pattern and you will be able to usethe reference pattern after

Create "master hole" part with positioning hole pattern inside.Start all your holes containing parts with the iheritance feature from "master" part.Create first hole and a reference pattern after