How to constrain?

[mckenziewesley]

Hi

I have drawn essentially a big wheel. I want to bolt a bracket to the inside of it. Any ideas on what the best way is to do this? The bracket has the same curvature as the inside of the wheel. Do i use a tangential mate? I want the bracket on the inside of the hoop so that i can eventually bolt the flat plate portion to something else.

Thanks so much!

Wes

[JD Mather]

First of all the radius of your bracket does not match the radius of your Hoop.

Your sketches are unconstrained and make no use of symmetry about the origin.

I would start by reading this document -
http://home.pct.edu/~jmather/AU2007/...L%20Mather.pdf

[mckenziewesley]

I realized after the fact that the radius's were mismatched. I was hoping though that the sketches would get the gist across of what i was trying to do. I'll read through that document and repost.

However, in the meantime, is what i'm trying to do possible? Could you tell me why it would be important to have symmetry about the origin? Ultimately this assembly will go into another assembly as a sub assembly and will be tied into that drawing.

That's kind of a problem that i'm having, i've read through a ton of stuff on inventor and i see lots of ways to do things, but, i haven't seen alot of "well, how come that way vs. this way" kind of thing.

Thanks for pointing me in a direction!

Wes

[mckenziewesley]

ok, i've read through most of it - referencing things to the origin point seems to have resolved my issue - well, that, and probably more importantly getting the radii the same.

Question on that. the problem was that my outer radius of the rectangular sweep was slightly larger than the ID of my hoop as well as the radius of the path line that i drew to sweep the rectangle along. What i would like to know is if there is an easy way to get the radii the same - what i ended up doing was progressively change the dimension of the distance of the swept rectangle from the origin until the radii were the same. This seems kind of backwards. Is there an easier way to do that, or should i just keep reading through that lesson plan?

Thanks!

Wes

[JD Mather]

I assume you know Hoop and Bracket are different widths (2.125 vs 2.25).
Not sure if you intended for the holes to line up.

[mckenziewesley]

yep, i fixed all of that. The problem became easier when i referenced everything to the origion. I don't know why, it just made it easier. I fixed the width issues as well as the radius issues and *poof* everything constrained like i kind of originally expected it too.

I think my problem was originally more in how i swept the arc for the top of the bracket. I had it as a 53 radius, but, the top of the swept rectangle was always something like 53.0XX - i.e. a larger radius and i believe that is why i had trouble getting the ID and OD to fit together. I'm sure there is a better way, but, i ended up just decreasing the distance of that rectangle to the origin such that the "top" of it followed the path my arc. Once i did that, everything else worked itself out.

Right now i'm working on getting the completed hoop + bracket assembly to mate to a couple of rollers that i am going to put onto a base. This one is kind of tricky as well. Looks like i'm going to have to face-face constrain two of the rollers to the base and then tangentially mate those rollers to my hoops. Then i will have to tangentially mate the back rollers to the hoop, and then face-face mate their bases to the base of the assembly. I tried just mating all the rollers to my flat base and then mating in the hoop, but, i ended up with my hoops sitting below the level of my bottom roller surfaces.

I'll post up a pic of everything once i finally figure it all out.