Not as complicated as you might think really. Basically they will be the same design only I will be using 3/4"x3/4"x1/8" thick angle iron for most of the rack and the legs and I'll be using a 14ga steel mesh in place of hardware cloth. It will naturally cost more in materials but they will last essentially forever and of course won't be chewable. Right now we are running 32 tubs but with the steel racks I will go up to 120 tubs. Not counting the cost of the tubs I will be at around 1400.00 worth of steel at current prices. Sounds high but they will basically be very similar to freedom breeders racks and 1400.00 is WAY cheaper than 120 tubs of freedom breeders.