Question Help understanding drill bits

Hello,

I've always been a DIY fan and I'm about to take the next step which is to buy a Stepcraft.

I have no experience with CNCs and the only thing I know is how to work with Sketch up and design things that I want to cut.

I'm going to buy the biggest model (Stepcraft 800) but I have questions regarding the drill bits because honestly I don't know which ones are appropriate for me.

I'm planning on cutting balsa wood, mdf and aluminium. I've been watching hundreds of videos on youtube to learn a few things and people use all sorts of drill bits with the final results varying a lot ( by varying I mean that some of the pieces look really smooth and another ones still need a lot of work to finish/polish the edges ).

Could someone please explain me what kind of drill bits are the best for this?

Also, does the Stepcraft kit comes with any spindle or do I have to buy one separately?

Drill bits are for drilling holes, milling bits are what you probably need. I suggest getting carbide bits, not HSS or similar. Number of flutes and size depend on spindle, cutting parameters etc. 2 flutes is popular for smaller diameter mills. You can use the data what others have used in videos and in this forum for Stepcraft, not some high power machine. Search as much information you can and learn as you go. I would keep separate milling bits for wood and metal, even if they are exactly the same. Some information can be seen here for example.

Probably there are no best milling bits but many different ways to reach the same goal. Finishing quality depends on more than just a milling bit used. Suggest starting with about 2mm bits because smaller can break easily and larger create bigger cutting forces.

The kit probably has no milling spindle included, contents are usually described by the seller.