How do you get makers in harvest moon ds?

Inside the barn will be 6 spots for the machines. The Makers are built by Gray at Saibara Shop. Gray requires you to give him a piece of Adamantite, which you can find inside of the 3rd Mine. You will also have to pay him 20,000 G for each machine you have him build.

To use the newly built Maker, hold the machine's required item in your hand and then press the A button while standing in front of the machine to toss it in. You can throw in stacks of items so you don't have to convert an item one at a time.