at first, i would suggest you to go for a readymade acrylic base, as it is not home made actually. i have uploaded the structure of my base. you can find many structures in google.

you need to have 4wheels of equal length, height and width. you need to maintain exact figure for all four.

attach the two l-293d motors to both the front tires.

now you are almost done with the hardware connections.

place the decorated(connected with micro-controller and all the necessary connections as per the uploaded pic) bread board on the acrylic base.

that it's friends your project is done!!

hope u liked it.

if i had missed anything and you have any doubts regarding the project, don't hesitate to message me.:)