Aaaand here it is! A sorting/retrieval system using only Railcraft and optional Iron Chests. Now, it's slow, and I had to get creative with the item retrieval system, but it
WORKS. Try that one on for size, @
SatanicSanta !
Really cool, but having to order 27 items every time you just want one really puts a limit to how useful it is. Also ruins the possibility of ordering a piece of cobble along with a piece of oak wood.
If you don't just fill every single Item Loader and have the cart fill with all the items, but instead control the items going into the loaders, you can directly control which items you get:
The Itemducts feeding the Item Loaders are set to "On redstone high". You can set them to the stack size of your choosing.
Each Itemduct is them wired up to a button by the MFR rednet cable on each their separate channel. Each button press(Use wood buttons, not stone due to the longer redstone pulse) then results in a stack of the coresponding item being transferred down into the Item Loader. Once you have ordered the items you want(you can order up to 9 stacks of each item(if you set the loaders to "ALL", and multiple different items at the same time. If the total ordered items exceed the carts capacity, just send it around another time.), click the Stone Button to send the cart off to collect the items. If there are no items in the Item Loaders they will immediately send the redstone signal to let the cart pass(if set to Immidiate).
For more items you can simply set up more Item Loaders in the same way on the same track. Just make sure to keep the Rednet cables separate(or use coloured bundled cables).