Help with odd pattern

[victor-dot-com]

The ID team gives me this vent pattern that I am having a hard time duplicating. A little background first. I get models from ID team, which is created in something other than Creo. I recreate it in Creo, so that engineering can have fully parametric models. With that out of the way, please don't suggest I use the ID model.

Attached are few images to help explain what I need, and what my problem is. The first image shows the ID model. The ribs are fairly uniform and so are the vent slots. But they are not as perfect as I would like.

The second image shows how I went about trying to duplicate the pattern. Curve 1, is the curve that controls the angle of the vent, as per ID's instructions. Each slot is made normal to the curve, passing through a point on Curve 2. I first tried putting the points on curve 1, but the results where much worse. The points are created by a fill pattern on the curve.

Image 3 shows the result and the problems, which is non-uniform slots/ribs.

Anyway, I am trying to get uniform slots and ribs. That is the slots all look the same, and the ribs all look the same. Not that ribs look like the slots. One thing you will notice is that the slots on the ID model fan out in width. I have not tried duplicating that yet. I'm trying to get the spacing right first. I'm at a loss as how to accomplish this. Please help. Thanks.

Victor

 

[dgs]

I face similar problems all the time. It's an interesting and sometimes fun (sometimes maddening) challenge. This one looks like both.

You've probably already thought of this but, do you have access to the native ID model (and the proper software)? I find that can be helpful in determining design intent, but it isn't always.

If not, can you get a neutral file import that you can bring into Creo as a reference to build your geometry over? In particular the ID version fo curve 1 would be valuable to import. It looks like a spline and because it's controlling the angle of each vent, getting it just right is going to be important.

That said, it looks like each edge of each slot is normal to curve 1. So, in your sketch, make sure that each side is constrained normal to curve 1. I think a pattern of points along curve 2 is the right way to go, but I'd make those points align with the corner of the slot, not the center.

What I'm not yet sure about is how to make sure that the slot width equals the rib width. You could pattern twice as many points, but once you align your cut with the second point the reference pattern will fail. Plus, you'll have twice as many cuts as you need.

I'm wondering if you simply make it visually the same if it'll come out OK.

I hope that helps. It looks like a fun challenge.

 

[dgs]

BTW, what version of Creo (in case I get time to play with it)?

 

[dgs]

OK, I got some time to play with it and I'm running into the same issues that you are - where the pattern transitions around the corner the spacing isn't right. I can get close, but not quite the same.

I'm questioning if the ID model was patterned or if the vents are truly perpendicular to that spline in the image. Being able to see the native would be a big help.

I've attached my Creo 2 model here, for what it's worth. I had to suppress all the features to get the zip file under the silly 97KB file limit.

 

[victor-dot-com]

Hi Doug,

Thanks for the help! To answer your questions, yes, I do have the ID model. I replicated all the curves needed in Creo. I am using version 3.0

Your idea of creating two sets of points is something that has crossed my mind. But haven't tried it yet. Yes, I always enjoy a challenge and thankfully I have the time right now to figure this out. That isn't always the case. Otherwise I probably would have used the geometry ID provided at this point.

I like how you defined the spacing between ribs using a circle. That has got the gears turning at high rpm right now.

I tried attaching my models in my original post, but the size limitation prevents that, even with everything suppressed. I'd be happy to email them to you so you can see the actual geometry. Thanks again!

Victor

 

[dgs]

What is the ID model built in? If it's Solidworks, I can take a look at it. I'll PM my email address.