Autodesk Inventor

[#1]

I have a sheetmetal assembly with helical shaped parts. I need to place about 50 little brackets and some corresponding rollers along the length of these helical pieces. The spacing is even so a pattern would be perfect, except I don't know how to get it to follow the shape of the part. The brackets are located to slots in the helical parts which were made with a rectangular pattern in the unfolded state. I tried to do a "feature pattern select" but it only saw the rectangular pattern as it is in the unfolded state (a straight line). I then gave up on patterns and started working on manually mating them into place but realized that the geometry of the slot was distorted (theory) and didn't leave me with any useable surfaces.

Does anyone one have any ideas on how to approach this? I'm at a bit of a loss.

I can post files if anyone wants to see them. (IV 2012)

[#2]

Create a pattern of workpoints (and probably work axis) in the part file.

You can then use this with the Feature Pattern Select to place your components.

There is a similar example here.

http://home.pct.edu/~jmather/skillsusa%20university.pdf

[#3]

I tried your suggestion (and re-read your skills USA pdf) but I'm getting some funny results. The points are finding their way off of the part and twisting a bit.

[#4]

The why makes more sense when I add the rollers. You can see how it's following the curve explicitly (not-unexpededly in hindsight) without regard for the other piece.

[#5]

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mrattray wrote:

  The points are finding their way off of the part and twisting a bit.

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You missed a step.
Attach your files (or simplified representative files) here.

[#6]

The pack&zip is too heavy to post (~3MB).  If you want to PM me an e-mail or ftp or something else of your liking I'd be happy to upload it.

[#7]

Find the largest parts (in file size).
Drag the red End of Part maker to the top of the browser hidding all features.

Save the file with the EOP in a rolled up state.

Now when you zip (or even if you don't zip) it will be far far smaller.

[#8]

I never would have expected that. If I hadn't gone and tried it just now and seen that moving the EOP reduced file size to a tenth of original I would have called you a liar. That's truly baffling to me being how the same data, in my mind, would still be there. I'll have to add that to my catalogue of magic CAD tricks. Thanks!

Anyways, files attached.

[#9]

mrattray, I can't help with your drawing dilema but i took a look at the model you posted and thought I should point something out to you.

Your inner and outer flanges should follow the path of the rollers more closely than they do. Why? because as they are in the model at present they would present a negative chamber to the curve which would cause anything traversing the conveyor to either fly off or to crash and congest, which is something I'm sure you would want to avoid.

Repositon the top slider and inner flange to match the rollers rather than trying to get the rollers to match the flange.

It's all about the centrifugal forces experienced by any mass traversing the conveyor.

I hope that all makes sence and that I haven't sounded critical at all, just thought you should know is all.

[#10]

I've read and reread your comment about 8 times now and I can't comprehend what you mean by "present a negative chamber to the curve" I assume you meant camber, but my very limited engineering background causes my brain to hurt when I try to figure it out. What I think you're trying to tell me is to have the whole chute follow a more natural curavture like the rollers are trying to do. Unfortunately, the strart and end points and orientations are set in stone at this point (approvals signed and all). The only place I have leway is in the between.

Back to the modelling cluster: I found some time to work on this thing this morning. I still can't find a way to get work features to follow that path. I tried adding the workpoints and adding them to the cut pattern in the unfolded state, but when I dragged the EOP back down to the folded state the work points failed to follow the bend.(see image) Just to add insult to injury, Inventor decided that I can't delete those points. I deleted them out of the tree but it only removed the original points. I even deleted and remade the pattern and they're still floating there. I tried dragging the EOP around to find a feature they may have magically become a dependant of, but they're still there even when I roll the part all the way to the top. Very frustrating.

I'll work on it some more through out the day, but if anyone has any ideas: please share!

Thanks