mixed units in bom not adding up

[RANDYWINDERS]

I have an assembly that requires lengths of chain. I used the roller chain generator around existing sprockets to get the basic solid into the assembly. There are two of these in the assembly.

I am generating a mechanical bom for the customer showing speed reducers, bearings, sprockets, and chain. So I need to show quantities of each for everything but the chain.  I need to show chain in ft.

I used the parameters generated by design accelerator as follows:

I used da_p, pitch, and created a user parameter called pitch

isolate(da_p;in;ul)

I then created another user parameter called length

da_X * pitch to get the total length.

this is a unitless parameter

I then added 5% for sag in the chain, parameter called stretch,

length*.05

Finally I add the two together to get the total length

isolate(length+stretch;ul;in)

I use custom parameter formatting to display in ft. the preview looks good.

in document settings under the Bill of Materials tab I set Base quantity to the user parameter. This sets the base unit to inches.

On the parts list I use value substitution with my user parameter.

The problem is that the quantity shown  in the parts list is equal to only one length of chain instead of the two that are in the assembly.

 If I dont use value substitution  the value shows correct but with a decimal point. I want feet and inches.

Can anybody tell me what I am doing wrong? Am I missing something?

 INV2009