Help with a 'tangent' mate

dr_hutchinson

If you look at the public document;

1-tool alone.step

Can anyone suggest how you apply a tangent type mate to one of the bearings and the upper contact disk, so that when the handle is pulled the contact disk is raised. Dare I say, that this is trivial in SW, but appears more difficult to implement in ONSHAPE?

Thanks,

Barry.

andrew_troup

@dr_hutchinson
If you look back through recent posts, there have been several on ways to achieve similar aims, with the words "tangent mate" in the title. There is a link to a model by @philip_thomas in which he provides some examples.

philip_thomas

Here is a document that includes examples of various mate types (including tangent)
https://cad.onshape.com/documents/6ba1e39775d942b78b0c84f1/w/cdfcad3a3d7f4565ad4ffef4/e/61db20db6c0b4197818cef4d  

dr_hutchinson

Before posting my query I looked extensively at all previous 'tangent mate' questions and studied Philip's examples closely. However, I was not able to apply ( because of my lack of understanding I am sure ) the appropriate technique to my example. Philip, would you mind making the mate in my example so that we can see exactly how it is made?

Many thanks,

Barry.

nav

Hi @dr_hutchinson here an approach, in the bearing in Parts studio I drew a mid planes and put a Matte conector perpendicular to the line of the center sketch:



Went back to assembly used Planar mate +Solve and got the desired motion (hope it helps)

 

andrew_troup

nice demo, @nav !

Another approach would be to set up a planar mate with a connector at the central axis of the bearings, and type in the radius of the bearing under "Offset" for that mate.
Effectively constraining the axle to remain the correct distance from the underside of the rolling-contact flange

philip_thomas

dr_hutchinson said:

Before posting my query I looked extensively at all previous 'tangent mate' questions and studied Philip's examples closely. However, I was not able to apply ( because of my lack of understanding I am sure ) the appropriate technique to my example. Philip, would you mind making the mate in my example so that we can see exactly how it is made?

Many thanks,

Barry.

Barry - no problem.

The solution is EXACTLY as i show in my weldment example.
1) I added a mate connector to the 13x4x5 bearing in the part studio (look at the feature tree)
2) In the assembly i used a planar mate between that mate connector and the underside of the pull disk - BOOM DONE!
3) I changed a couple of the cylindrical mates to slider mates. This reduces the number of degrees of freedom in the system. This was not necessary, but just an example of good modeling - dont leave more degrees of freedom than you need.
4) I added (rotational) limits to mate Slider 2 to limit the motion of the lever (again not needed)
5) I renamed a couple of the key mate relations so that i could find them more easily (we (Onshape) need to work on improving this).

I hope this helps (here is the (public) document)
https://cad.onshape.com/documents/4228e5cabaa44cdea4579b76/w/0522ecc2ea1349238d98ea8f/e/47e1a8c3b5f64c818da7e46e

philip_thomas

Ok - like 3 people beat me to it while i was messing with it.
THANK YOU ONSHAPERS!
(although mine had limits too )

nav

 philip_thomas said:

(although mine had limits too )

touché @philip_thomas  

dr_hutchinson

Thank you for the replies. There are two things which I had missed. The first was to create the essential mate connector on the bearing in the part studio. Dropping back to part editing whilst in the assembly mode to achieve a mate is something completely alien to the SW user. Andrew's approach of using an offset is something which will come to me with experience (I hope)!

Barry