Feature Driven Component Pattern - Patterning Seed Feature

[CADFlyer]

Our company uses a lot of nuts, bolts, screws, rivets, etc. that mate to slotted holes on large flat sheet metal surfaces. The slot spacing may vary but tends to be a repetitive (only sometimes linear) nature. So, I have been trying to come up with an intelligent approach to adding fasteners to a slotted hole, and then easily pattern the fastener along all the slotted sheet metal holes. Keeping rebuild time & mates to a minimum would be a plus.

I started using the ‘Feature Driven Component Pattern’ feature in an assembly to pattern a component ‘Sketch Driven Pattern’, which worked fantastic. (I mated a bolt concentrically to a sketch ‘point’ used in the components sketch pattern, and then use the assembly ‘Feature Driven Component Pattern’ to pattern the bolt throughout the component’s ‘Sketch Driven Pattern’ slots).

The problem I found when I got to my drawing, my part count was off. After doing some digging I found that when using the ‘Feature Driven Component Pattern’ it was actually making a copy of the seed. Example: Pattern a bolt that is positioned in hole #1 using a hole pattern of 2 holes, the seed (#1) and hole #2. I am left with 2 bolts in hole #1 (the original & a patterned bolt) and a bolt in hole #2.

I know I can go back, after the fact, and indicate the seed as ‘Instances to Skip’, but this is not intuitive to how any other pattern feature in SW acts, as far as I know. So now to my question…

Has anyone that uses this function seen this before or understands the logic behind why it would copy itself?
Does anyone have any alternate methods to mating to a slot and/or patterning fasteners in a random planar pattern?

SW2012x64
Windows 7
HP Z210
i7 3.40GHz
16GB RAM
NVIDIA Quadro 2000 (current approved driver)

 

[Jboggs]

In my limited experience with sketch driven patterns i have sometimes seen the count of my patterned objects is off by one like you descibed. In those cases if I go back and remove the "sketch point" that is associated with my seed feature, that fixes the count. Its like it is copying the seed on itself.

 

[Azum]

The same happens when you copy holes around a circle as in a pcd only in this case it puts a hole at the centre of the pcd.
Very annoying as the hole call out wizard calls up one hole to many and the shop floor guys ask where it is
or you have to open up the array and get rid of the extra hole.
Seems like a glitch in SW but I bet its been around for years

 

[IAMIS]

I generally use the hole pattern (tapped holes) that sits below the slot to make a feature driven pattern. It does require that you mate one of the fasteners to the hole first instead of being able to use a smart mate to the feature in the surface that, usually the flat washer, the first fastener is in contact with. Of course this may be no help if your part with the slots ties together multiple parts that have the tapped holes in them.