how to constrain to an endless profile, ie a belt path 1

[abeschneider]

I am modeling a system which incorporates a belt with attachments. I would like to be able to constrain a sketch (and later, assemble objects) to a profile which resembles the profile of the belt going around two separate pulleys. (The shape is similar to that produced by the "Elongated Hole" command in CATIA Sketcher).

Problem is, when I try to constrain a sketch object in another sketch to such a profile, it only constrains it to the picked line, or arc segment, not to the "infinite loop". Is there a way to "join" the 2 lines & 2 arc segments into 1 endless feature?

I've tried using the "Join" command in Wireframe & Surface modeling but the Curve it produces still is composed of the independent straight and arc segments.

Any ideas? Confused? I can try to explain better...

 

[solid7]

Extract points from your geometry, and create a spline from them. Be sure to select the "close spline" option. (the more points, the better)

You will still have a start/end point, but it does away with the annoying segmentations.




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[itsmyjob]

make a JOIN with FEDERATION (all) with your Belt Sketch. (just the Sketch in the JOIN). Then use the Federated JOIN for your constraint.

Eric N.
indocti discant et ament meminisse periti ​

 

[abeschneider]

itsmyjob

it's your job! thanks for the tip; it was a simple way and seems to have done the trick. I now have a parametric, endlesss loop. Thanks.

 

[itsmyjob]

just trying to help. Glad I can make it.

Eric N.
indocti discant et ament meminisse periti ​

 

[abeschneider]

Reviving an old thread...

I've succesfully "joined" with federation; then published the resulting continuous curve. I want to Publish this sketch, and use it to constrain other Parts in a Product.

However, when I try to constrain to the line, I am not allowed by CATIA to do so.

Is it possible to mate (constrain) to a Joined curve?

Thanks...

 

[jackk]

What does the error message say, Abe?

My guess is the part your working on is "out of context" (check to see if it has a yellow, green or brown gear on the icon in front of the part in the assembly - my guess is it's brown)

You should be able to link to the published join element.

 

[abeschneider]

jackk,
there isn't an error message per se (no popup for example), it just won't let me mate to the joined curve. When I use the constrain tool, I select a point on the Part I want to constrain, and then I cannot actually select the joined curve (in the prompt area at the bottom left of the screen, it indicates it's waiting for me to select a point, line, or plane.)

An analogous situation to what I'm trying to do, would be to constrain a point to the surface of a cam.

Does one have to use the DMU Kinematics workbench to do cam-type mates?

Thanks for trying to help me on this; and I apologize if I'm not communicating the problem very well.

 

[abeschneider]

oh, and jackk, the part is not in context of the assembly (the the Part's gear is brown; actually one part is a skeleton with the joined curve "cam shape"; and the other part is what I'm trying to constrain to the joined curve...)

and both parts are not in context of the assembly; both have brown gears.

 

[jackk]

I misunderstood your contraining problem - thought you were talking about sketch constraints. Ignore my "brown gear" comment earlier.

If it won't let you pick something when making an assembly constraint, could the two part already be constrained to each other?

You want to make a point on part1 coincident to the join curve in part2 - right?

You should be able to constrain to the federated Join. And I don't think you have to use DMU Kinematics for cam situations.