I am going to build a shelving unit to hold 3, 6 x 2 grid cages. I believe I know what I'm doing regarding the wood shelving, grids and coroplast but am not sure regarding the doors. I want the complete front to open up so all the bedding can be swept out at once. How do I do this? By the way I'm building this for a pet supply store who has quit selling live animals but has some really old boars who need better cages. I want their last years of life to be better than living in tiny cages. I got the 2 x 4s for free and all it will cost the store is the coroplast and grids. I found colored grids on clearance at Shopko for $10.00 a box and the coroplast is only $12.00 for a 4 by 8 foot sheet. The owner can't seem to get what the cages are going to look like in her head but she's excited about seeing the piggies in better cages.