Constraints query - tangent & motion

[jhiker]

Just messing with the 'new' constraints. I have anchored the large cylinder and applied a tangent constraint to two of the smaller ones.
How do I drag the smaller one to make it roll round the OD of the larger one as shown in the constraints help dialogue example. It will only drag along it's own axis.
I'm missing something here.

 

[idslk]

Merry Christmas Jeff,

toggle "Minimum Motion" to off


Regards
Stefan

 

[jhiker]

Merry Xmas Stefan - and thanks.

 

[JST]

Be aware that the minimum motion defaults to "on", and resets it self to "on". That will mess you up on a regular basis otherwise. At least it does on the previous version, I am not installing 22 yet, too many reported hassles..

 

[HaroldL]

I still don't fully understand why there is a Minimum Motion setting and I think Alibre is the only 3D CAD program that I've used that has it. At least I don't recall having in SolidWorks or I-DEAS. I've always left it in its default setting and can only think of one time that I had to turn it off. If the constraint mechanism is working as it should why is there a need for it?

 

[idslk]

https://www.alibre.com/reference-videos-assemblies/



Regards
Stefan

 

[Lew_Merrick]

I still don't fully understand why there is a Minimum Motion setting and I think Alibre is the only 3D CAD program that I've used that has it. At least I don't recall having in SolidWorks or I-DEAS. I've always left it in its default setting and can only think of one time that I had to turn it off. If the constraint mechanism is working as it should why is there a need for it?

Hi Harold -- I agree. I cannot think of a condition in my where the "Minimum Motion Tool" would be of value. Having the ability to turn it off would fall in the "good things" category in my "book." -- Lew

 

[bigseb]

I still don't fully understand why there is a Minimum Motion setting and I think Alibre is the only 3D CAD program that I've used that has it. At least I don't recall having in SolidWorks or I-DEAS. I've always left it in its default setting and can only think of one time that I had to turn it off. If the constraint mechanism is working as it should why is there a need for it?

Hi Harold -- I agree. I cannot think of a condition in my where the "Minimum Motion Tool" would be of value. Having the ability to turn it off would fall in the "good things" category in my "book." -- Lew

You guys should check out IDSLK's link. Minimum motion definitely has its uses.

 

[JST]

As long as you remember that it can and will mess you up on a regular basis if you forget about it being on by default.

For some things it is great, but for many things it is a pain. Being able to have it be off and stay off would be good.

 

[HaroldL]

Hi Harold -- I agree. I cannot think of a condition in my where the "Minimum Motion Tool" would be of value. Having the ability to turn it off would fall in the "good things" category in my "book." -- Lew

Lew, I think you misunderstood my comment. I said:

...(I) can only think of one time that I had to turn it off.

I always leave it in the default setting, ON, otherwise I found parts moving that I didn't want to move. The only thing I see it doing by turning it OFF is that other parts would move that shouldn't which would indicate where constraints are missing, as the video shows. So maybe that is a good thing.

 

[HaroldL]

How do I drag the smaller one to make it roll round the OD of the larger one

You only need to add a Coincident constraint to align the small cylinder's face to the large cylinder's face. This works without turning Minimum Motion off.