Dynamic block scale issue

[Anonymous]

hey guys,

I'm having an issue with a block im trying to make (attached), I'm making the block for a tail pulley on a materials handling conveyor. the work point (WP) is a fixed point. the RH Value is a variable and is fixed from the WP to top of pulley. The pulley can scale from the top point downwards to represent any diameter pulley. if you can open the file attached and use the grip to adjust the pulley when RH=200, it works as I need it to however when the RH value changes and the pulley grip is used, notice that the top of pulley point also changes, also notice that the two top triangles are now not aligned. I've been working on this for 2 hours using constraints, trying to join those top parameter points together so they move as one but it is becoming very frustrating, any help would be appreciated.

Regards,

Liam

[Libbya · Accepted solution]

If I understand the desired function, I think the following accomplishes it.  It allows you to set RH and radius independently.  Neither affects the other value.  RH always sets the distance from WP to top of pulley.  Radius sets the radius of the pulley from the top point.  

[Anonymous]

that is exactly what i was trying to achieve! thankyou so much!