Hi Bunker45,
Dion helped me with my RIMS build back in 1996. He was one of the RIMS pioneers in our area. What I do with beersmith using my RIMS is to set up the mash as single or double infusion with a mash-out and a sparge. Beersmith will calculate the dough in, infusion, mash out, and sparge volumes for me, but since my temp ramps are done with my RIMS heater, I just add up the dough-in, infusion, and mash out volumes and this is what I use for the dough-in volume. If you want to go with no sparge, just add the sparge volume to that sum and there you go. I hope this helps.