Milling drill bits


I am looking for information on drilling holes with a drill bit rather than an endmill using the xcarve. I am using Estlcam as my controller/CAM which has a drilling feature, where it pecks at the hole to clear the chips. I can’t seem to find the right name for bits that have a standard 1/4"/1/8" shank size and a variety of drill size diameters. I know of those small 1/8" shank dremel bits used for drilling holes for PCBs, but I’m thinking larger scale such as a 1/4" drill. Most, if all my drilling will be in wood.

  • Is there an adapter that I could stick any old drill bit in (kinda like a chuck on a drill press)?

  • What would be the name for bits that are used in a CNC machine? Links are appreciated :slight_smile:



Most of the ones I see have a hex shank…

There is always the step bit option, which works well for making lots of different hole sizes as long at the material isn’t too thick.

I think dowel drill is the term you are looking for. Or these they go to .25 inch.

If you can get access to a lathe you could gut a electric drill and have the shaft attached to the chuck turned down to .25.

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Drill Mills would work. I order then from grainger. They are basically pointed endmills.

They are good for pick drilling, but also Chamfer ING edges.

Oh wow, I didn’t know that style would go that big, Thanks for the link!

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Depending on material and hole size you’re sometimes better off with the “Helical Drill” function and a small endmill, especially for large diameters.

  • The issue with drill bits is the lower rpm limit of the router or spindle motor -> it is usually just too high for large diameters.
  • Drill bits require very low rpm compared to endmills -> if rpm is too high the bit will get very hot and cause all sorts of trouble like burned edges, molten material or just gets dull and breaks.
  • A helical drill on the other hand uses an end mill with smaller diameter than hole size and cuts in a helical / spiral fashion. This causes much less friction and heat and may also save you some tool changes:

Peck drilling:

  • Small diameter holes
  • Deep holes
  • Very good roundness

Helical drill:

  • Large diameter holes
  • Much more tolerant in terms of feeds rpm
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That’s exactly what I was thinking…

Thank you everyone for all the information! I kinda got the idea when I watched someone at my work use a manual mill to drill some holes. He just threw in a chuck adapter, used a normal drill bit and basically used it like a drill press. But yes, on manual mills you can go much much slower speeds, which he adjusted when he was drilling the holes.

I have been using your program for some time and to be honest I never thought of using the drill feature as I thought it was made more for threaded holes or drilling with drill bits (pecking). I have always been using the “Inside” feature to drill out holes. Is there much difference between the two features, inside vs. helical drill?

There are 2 main differences between the “inside” and “helical drill” function

  • The “inside” function does not necessarily clear all material inside the hole. If tool diameter is smaller than half hole diameter a core will remain that may cause trouble once it loses contact to the rest of the material. The helical drill removes all material inside the hole no matter the diameters.
  • The “inside” function plunges deeper step by step while the helical drill goes deeper continuously. The latter improves the roundness of the hole and works a bit faster.

Thanks for the Estlcam tip!
Are you able to help with some settings for communicating to the X-Carve machine?
Thank You in advance,