AE2 way of dealing with chanced recipes

Impulsed Pattern Provider

The Impulsed Pattern Provider is a specialized crafting block that sends the last used pattern when triggered by a redstone signal.

How to Use

1. Place the block: Attach the Impulsed Pattern Provider to your ME network like a normal Pattern Provider.
2. Open its GUI: Right click the block to access its interface.
3. Insert patterns: Add any processing patterns into the grid slots as usual.
4. Trigger crafting: Apply a redstone pulse to the block. Each rising edge will push the last used pattern into the connected machine again.

This way you can automate recipes with chanced outputs. The most basic setup would work like this. When the machine fails to produce your desired thing, detect that (for example using the Signalling Interface) and send redstone pulse to the provider. It will push the pattern again.