CNC Mill mod for Anet A8 (Under $30 USD)

This motor holder design adds mill-like capabilities to Anet A8 without removing any other feature from your printer.

Parts I had to buy:
12V DC Motor: http://www.baudaeletronica.com.br/micro-motor-dc-12v-6500rpm.html (R$41.90; around $11.40 USD)
Mandrel: https://produto.mercadolivre.com.br/MLB-881443606-mini-mandril-com-adaptador-tipo-dremel-micro-motor-_JM (R$39.90; around $10.85 USD)
That pink drill bit: a local building materials store (R$10.50; around $2.85 USD)
Total: R$92.30; aroun