connect a curved surface so it stays perpendicular to another - what joint typ is this?

[Sungod3000]

Hi, 

Im having some trouble finding the right type of joint for these to parts https://a360.co/355U6p8

I basically want to develop a jig that guides the knife over the wet stone, while forcing the blade to be always perpendicular to the stone. (For simplicity’s sake, I'm ignoring the blade angle for now)

In the end I want to build a jig where i can clamp the knife onto and always drag it along the a path/ v-grove, so I always get a perfect grind. 

I added a helper surface that represents the contact point to the stone, but now Im stuck.

I tried then to connect the knife edge to the helper surface without the being perpendicular, but ran into the same issue. 

Can someone give me a pointer on how this relationship is called in fusion?

Thanks F.

[mango.freund]

hello @Sungod3000  that doesn't seem difficult to me.

put a joint origin at the point of the knife where it should sit on the stone and a second swivel joint on the stone axis. note that you can use the joint offset to set the ideal height to the stone.

where is the work?
how can one help you without the f3d file?

 greetings mango

[Sungod3000]

Added file to the original post. 

I just tried that, but how can i make the joint itself slide? Having one single point on the blade slide along the axis of the stone would be simple enough. but the knife itself needs to adjust its angle towards the stone at each point of the knife. Can i maybe force a tangential relationship between knife edge and stone axis?

[Sungod3000]

Made some progress but still cant quite wrap my hand around it. 
I added a pin and managed to connect the knife around the pin with a contact set. If I manage to joint the pin with the helper surface then the knife should push itself always in the right orientation...