How do you make an ATM card from abs?

It's not that simple ! Modern ATM cards have an embedded chip, and a magnetic strip - both of which are read by the machine when you insert the card. The data on the magnetic strip tells the ATM which bank (and branch) holds the funds for the account. Additionally, the info on the chip is also tied to the account. If the data on both parts of the card doesn't match an existing bank account, the card will be rejected.

That's excluding the fact that - if you did make an ATM card, and try to use it - you would be guilty of fraud !