Bad Sounds & Broken Bit

First let me tell you I am a complete novice. The machine is built. I think I have it properly adjusted. First the belts kept slipping so I was told to use zip ties to hold them in place. Problem seems to be resolved still seems a bit clunky to me. Next the drill bit kept going too deep into the wood and slipping from the holder. I used pliers to hold them into place. This seemed a bit overkill to have to do this. I should have known because on my next test the bit snapped. I am using an xcarve machine, 500 mm board, ACME lead screw, 24 volt DC spindle, snapped what was a 1/16" drill bit bought from inventables, using MDF board, and cutting a simple C shape to test. I am wondering if the MDF board just is too wicked for the bit, being soft in some areas while too hard from glue in others? Is it just a hopeless material or user error. Really hoping for user error because the panels are cost effective for my projects.

Thanks for reading,

Updated info: The reason I think there may be an issue with the board is because I had originally started out using the laser cnc at the library and it blew out their machine trying to cut through it. It simply wouldn’t work unless it was the slowest and highest setting.
Also when I say I am a novice, I am serious. I bought the pieces in May of 2015 and am just getting it running from being built.

I don’t understand. The pliers thing.

But start with checking to make sure you spindle is square to the waste board. Things don’t workout to well if your cutting at an angle. What is your spindle speed and your feed rate? MDF should be no problem for your machine.

Was it really a drill bit? Could it have been an end mill?

Better wording…Tighten it into place…very tightly.

Yes, it was the 1/16" END MILL that was included in the kit I ordered. I will try to be as careful as possible with my wording.

Any suggestions?

What was your feedrate? Depth of cut?

A guess is your cut was too aggressive.