topic Re: trouble constraining patterned parts in an assembly in Inventor Forum

trouble constraining patterned parts in an assembly

Anonymous — Sat, 29 Jul 2023 06:09:18 GMT

I am trying to draw a bowl that is made of staves (like a barrel). I have drawn an individual stave as a part and a base plate on which to assemble the parts. I placed a single stave onto the base plate constraining one vertex to be on top of the base plate. I then made a circular pattern of 16 staves. I can move or free rotate my original stave and do an update to get things close to where I want them.

I would like to add a constraint that adjacent sides must be touching. This should pull all the staves together so they touch. There should then be one degree of freedom left of the stave is tilted and I'd like to be able to adjust that by hand.

The problem is it won't let me constrain two adjacent sides to be touching. I suspect this is because they are in a pattern.

I could laboriously place one stave at a time (not using a pattern) and apply the constraints, but that is tedious at best and also doesn't let me easily change number of staves.

I've attached a zip file of my design files in the hopes that someone can help me.

Of lesser importance, if someone can tell me how to color every other stave a different color, I would appreciate it.

Thanks

Re: trouble constraining patterned parts in an assembly

BDCollett — Sat, 29 Jul 2023 12:24:09 GMT

I would design it as a single multibody part and adjust with parameters until it looks right, then drive the assembly level part with that same pattern in the master.

Much easier to control.

Why does the Stave model have so many features and just to end up as a simple shape?

Re: trouble constraining patterned parts in an assembly

SBix26 — Sat, 29 Jul 2023 15:16:14 GMT

Do you have a picture of anything like what you're trying to achieve? I don't think that with a prismatic stave you can do what you're trying to do. It's geometrically impossible.

One way to prove it to yourself is to cut the number of staves down to three or four and see if you can do what you want that way.

Sam B

Inventor Pro 2024.1 | Windows 10 Home 22H2

Re: trouble constraining patterned parts in an assembly

Alexander_Chernikov — Sat, 29 Jul 2023 17:56:50 GMT

You need to add at least 3 more assembly constrains - 2 angles between planes and a distance from base axes.

Indeed, first you need to install one element using constrains, learn how to control it, and then create the pattern.

It is convenient to control the parameters using the iLogic form.

You can color elements only with the help of a iLogic Rule (on the base of https://forums.autodesk.com/t5/inventor-ilogic-and-vb-net-forum/assembly-pattern-element-appearance-overrides/m-p/10065650#M120814).

All this is shown in the attached archive.

Re: trouble constraining patterned parts in an assembly

Anonymous — Sat, 29 Jul 2023 21:48:37 GMT

There is a video at https://www.youtube.com/watch?v=xgQvwTYMlMk which shows the type of thing I am trying to do. Watch it from the 5:20 minute point if you are interested. Here are a couple of screen captures. This first one shows staves cut with a simple miter that form a vertical sides barrel or bowl,.

Below you see it with a cone he about to shove into the center.

Below you see he has shoved a cone into the middle and twisted the staves so the still fit together.

And below you see the bowl after he has glued and turned it.

My desire is to do this in Autodesk Inventor first and play with various angles to see how it looks.

Re: trouble constraining patterned parts in an assembly

Anonymous — Sat, 29 Jul 2023 22:01:37 GMT

I will give this a try. The problem is I don't know the angles the staves need to go at to fit together. If you look at the photos (and perhaps the video) in my previous reply, you will see that in real life, one doesn't need to know the angles, one can just rubber band the parts together and they twist to fit. I was hoping I could make this happen with constraints in the assembly.

Re: trouble constraining patterned parts in an assembly

Anonymous — Sat, 29 Jul 2023 22:12:46 GMT

Wow! It is really cool what you have done. I can learn so much from your example (never having used iLogic before or made a from with sliders. Thank you so much. I will accept this as the solution.

Re: trouble constraining patterned parts in an assembly

BDCollett — Sun, 30 Jul 2023 21:13:22 GMT

@Anonymous wrote:
Wow! It is really cool what you have done. I can learn so much from your example (never having used iLogic before or made a from with sliders. Thank you so much. I will accept this as the solution.

My solution was similar using iLogic forms, they are really great for stuff like this where you need to easily adjust parameters and watch the result.

I think something that you might be missing with this, wood flexes, and the model does not.

No amount of adjusting the angles and pattern is going to have these pieces fitting together like that video.

At the 10:00 mark you can see him adding pressure to make it all fit together.

He then turns it down to get the smooth shape.