Geometry is not supported for tangent mate

bill_daniels

I'm trying to set a tangent mate between one of the KR40 cam followers and the heart-shaped cam but I get the error message in the title.
https://cad.onshape.com/documents/5cd4f1ad91e2317af733bc66/w/e355617edc071a7caaecd8e2/e/14a4788afb850ee6bc4bf610
It's probably something simple I'm not seeing.

john_mcclary

I tried using an edge on the cam. but it put it far to the left of the assembly and would flip around every once in a while.

https://cad.onshape.com/documents/4713bf3ac4dca43e54e200fc/w/df51e3b073f781a09f888cd1/e/6e0a25cdb2778198a0f13dcd

I got about half way there with a work around.. see if you can get any closer with that

bill_daniels

As near as I can tell, there's something wrong with how the cam was modeled.  The tangent mate is just not seeing the cam face where it appears to be.  Cams are VERY hard to model correctly - especially one like this.  It is essentially two Archimedes spirals, one a mirror image of the other joined at each end with a parabolic transition.

I find it requires specialized software or contracting with a company which specializes in plotting cams.  I wish there were an Onshape partner who did this.

konstantin_shiriazdanov

surfaces with spline cross section are not handled by tangent mate - this is my observation. I guess any surfaces except planes, cylinders, cones and spheres are not handled
for flat cams you can use my RectToPolar FS
https://cad.onshape.com/documents/0bb13c1b6ed6d4a6dd75cf99/w/b4493d47a45c27ce485c84b9/e/5831eadf8d16fc3e23560404

john_mcclary

Well I've done a tangent mate on spline before without much hassle...
See below:
https://cad.onshape.com/documents/292af20b6c06ac868e964caa/w/0e0df349e4eb1fb849ff3f48/e/066aadce57bdce7255d3e23d

I think it can be done, just may take something more clever than a tangent mate.

Once I get out of work I can look deeper at it too

alex_pineda441

Hello I have some really old winding machines that have these heart shaped cams I've looked up some stuff online but there is so much info don't know where to start. I there a semi simple formula to make them I seen videos on heart shaped cam parametric dims, but they do not work for these cams.