I just played this, I love it so much, but I just don't know how how to make the item, for example a bomb. But I don't know how to do it! Please help me!
How do you activate the recipe to make it?
The instruction manual for Spiral Knights is at wiki.spiralknights.com and is highly recommended.
Lots of items you can craft can also be bought pre-made, including from NPC vendors in Haven. Sometimes, low-level items are better acquired that way; learning a recipe moves it from your arsenal to your recipes menu and cannot be undone, so if it might bother you later to have your recipes list cluttered up with obsolete stuff you might want to think carefully about whether you need the ability to craft more of the same item.
The page on crafting has a picture of an Alchemy Machine which should help you find them in-game.
I have noticed three Alchemy Machines in Haven where you should always be able to access them:
one in the Town Hall, somewhere East of the Auction House,
one in the Arcade, at one of the desks on the South side of the room, and
one in the Bazaar, right next to Kozma and Brinks.
When you gain access to Moorcraft Manor, one is conveniently located right next to Brinks there too.
1. Acquire a recipe, it will be in the recipe tab in your inventory
2. Click on the recipe, a menu appears
3. Click Learn
4. Go to recipe machine
5. Select from your known recipe
6. Select "transmute"
...Profit!