Add formula to rebar shape parameters?

[Anonymous]

Hello,

I am apply a Rebar (code 75) to a Round Concrete column, while I am expecting to get the lap length of the Rebar according to below formula:

When I open the Rebar shape family, I can't see the formula which generates the result. I noticed there are so many parameters for the rebar as below:

My questions are:

1. Do I need to setup the formula to generate the lap length (for parameter B)?

2. Can I delete other parameters C - Q? I can't get the purpose of these parameters.

Thanks for your help.

[erik_snell]

I believe the B dimensions should vary bases on the bar size used. It would be the development length of the bar. Since this length is dependent on code and concrete strength it  is an instance parameter that would be set per bar. There is no need to delete the other shared parameters. They are loaded into each bar family and will be shown in the project any way because they will be in other shape families. 

[Anonymous]

Thanks for your reply. So does it mean the formula has already been set in the rebar shape family by default?

[erik_snell · Accepted solution]

Nope. I was saying the actual formula needed requires information that the rebar shape does not know, ie concrete strength. So the lap value must be entered as in the instance. The shape only has a default value that I believe is just a random number.