Ideally, you'd use a 1/4" drill bit. A drill bit will always be better than "drilling" with a router bit.
Couple issues with using drill bits, though.
Ideally, you'd spin them slower than the spindle should be run. The workaround is to just feed faster.
The other issue is that spindles aren't really made for drilling, and high thrust loads are not good for bearings. But if you are just drilling wood, the forces aren't too bad.
A downcut won't just overheat when plunging, it will burn the wood almost instantly.
An upcut would be my choice. It won't chip anything if you are just plunging.
On shallow holes, a compression bit will act like an upcut. But on deep holes, the chips won't come out, unless you peck drill with retracts to clear the chips.
Interpolating with a smaller bit is very common, but smaller bits tend to be limited in length, which can limit your hole depth.
If you are through drilling and need a good finish on both sides, a clean spoilboard will usually prevent chipping on the back side. Or, use a carbide tipped "V" boring bit. But those need to go pretty deep into your spoilboard.
Couple issues with using drill bits, though.
Ideally, you'd spin them slower than the spindle should be run. The workaround is to just feed faster.
The other issue is that spindles aren't really made for drilling, and high thrust loads are not good for bearings. But if you are just drilling wood, the forces aren't too bad.
A downcut won't just overheat when plunging, it will burn the wood almost instantly.
An upcut would be my choice. It won't chip anything if you are just plunging.
On shallow holes, a compression bit will act like an upcut. But on deep holes, the chips won't come out, unless you peck drill with retracts to clear the chips.
Interpolating with a smaller bit is very common, but smaller bits tend to be limited in length, which can limit your hole depth.
If you are through drilling and need a good finish on both sides, a clean spoilboard will usually prevent chipping on the back side. Or, use a carbide tipped "V" boring bit. But those need to go pretty deep into your spoilboard.