Hey Phillip, the reason you’re burning your tool and stock is because your feed/rev is too low.
Assuming you’re cutting at your lowest RPMs then 12/16000=0.00075in/rev. Moving slow while spinning fast you end up with your bit rubbing instead of cutting. Slowing down your plunge rate will make your feed/rev even lower and rub and burn even more. It’s the equivalent of having a very low chipload while milling.
A drill press spins at low 1000s and even 100s of RPMs. Compare this to the lowest setting of the Dewalt 611 at 16000RPMs. This is to be expected from a high spin router.
So if you cannot decrease the revs your only cure to bring your feed/rev up is increasing the feed (plunge). However, doing that on a hobby CNC which lacks the rigidity of a drill press you’re limited by the highest load the cut can produce before the machine starts flexing. In practice this means you might be able to drill soft materials and experiment to find a safe setting (if possible at all) with harder ones.
Try using a drill bit, at your lowest RPMs and start increasing the plunge rate gradually. If you hear your machine struggling, back off. If you still get burns at that point, the material you’re trying to drill is too hard for your (too high spinning) machine.
Btw, there are spindles out there with a low RPM range of 3000 or less.
I forgot to mention that the same way a smaller diameter endmill is designed for less chipload, a smaller diameter drill bit can work with lower feed/rev. So, this gives you a third factor to explore and possible expand your limits.