Drilling

[Simon Anderson]

I'm still a beginner to CNC machining, and I need to know about drilling holes smaller than 1/4" diameter. Is there a trick to simply using a 1/8" drill bit for making holes without ordering a special collet?

I assume the answer to this is "NO!", but can I use my 1/8" Tapered ball-nose to drill a 1/2" deep hole using a drilling toolpath?

Are there bits available that are smaller than 1/4" diameter, but fit in a 1/4" collet?

Any help would be appreciated. Thanks!

[steve_g]

Simon…
You are correct… the answer is “NO”. You will use a 1/8” router bit. For holes that are 1/8” use a “peck” drilling toolpath and for holes larger use a spiral cutting tool path. You can get 1/8” router bits with a 1/4" shank from many sources or you can get a 1/8” collet. I recommend you forget the ¼” to 1/8” adapters as many here on the forum have had bad luck with them.

Many CNC operators use a pocketing toolpath for larger holes as the plug is converted to sawdust rather than a projectile.

If you need sources for anything I’ve mentioned, just say so!

SG

[curtiss]

You can always use the bit just to "CNC mark" the holes, and then drill them to the proper size and depth with a regular drill.

[Simon Anderson]

Thanks guys for your quick responses. I've been looking and think there are some perfectly good 1/8" router bits with a 1/4" shank out there.

Simon

[Brady Watson]

If you have a spindle order an 1/8" collet from SB or Techniks (http://www.techniksusa.com/). If you have a router, order an 1/8" collet from PreciseBits (http://www.precisebits.com/gateways/ColletsNutsHome.htm).

Strategy will depend on the material you want to 'drill'.

Try to get away from necked down 1/4" shank bits. They are expensive compared to regular end mills, like 1/8 and smaller; they all take an 1/8" shank.

-B

[khaos]

If you have a spindle order an 1/8" collet from SB or Techniks (http://www.techniksusa.com/). If you have a router, order an 1/8" collet from PreciseBits (http://www.precisebits.com/gateways/ColletsNutsHome.htm).

Strategy will depend on the material you want to 'drill'.

Try to get away from necked down 1/4" shank bits. They are expensive compared to regular end mills, like 1/8 and smaller; they all take an 1/8" shank.

-B

A bonus to getting an 1/8" collet is the ability to use dremel and rotozip bits. They are great and WAY cheaper than some sources. Up and down spirals are available. Quality has been acceptable for the price.

[twelchPTM]

I recently bought collets from precisebit and it is a world of difference over the stubby collet chuck I was using. There certainly is a noticeable difference in cut quality