Low Tech Crafting adds just one new block: a “Better Crafting Table”.
It’s very similar to the vanilla Crafting Table, with the main differences being that it has a persistent inventory (ie. it uses a TileEntity to store the inventory), and it can be interacted with by “automation”, meaning Hoppers, pipes etc.
A couple of notable things:
1) While it has the normal maximum stack sizes when used by a player, the maximum stack size for automation (inserting by Hoppers etc.) is 1 item per crafting grid slot
2) The output slot is the first slot for automation, so pulling out items happens from the output slot first. So it’s not necessary to filter for the output item type.
This makes it possible to automatically fill the grid for each recipe, then suck out the “filler items” that should be empty slots in the final recipe, and then suck out the crafting result items.
The mod was started by Xcom6000, and the idea was to demonstrate to Mojang how the vanilla Crafting Table could be enhanced, so that it would also work for automated crafting contraptions.