[omegaguy]

Hi all, been a while since I've been on this forum and to be honest my home made CNC machine has been lying fallow for quite some time. However I've come across a project I'd like to make and needed some bits I presently don't have to complete the job. Unfortunately, in the Toronto area, there's not a lot of choice, but did find one place downtown that has a good selection. On going in looking for the bit I needed, a .5" ballnose, I was told by one of the assistants, that I should be using a router bit, and not a CNC bit, although in my limited expertise, I didn't realize that there is a difference, but was told that CNC bits burn out if used on a router, The router I am using is a, Hitachi Koki 2.25 Hp 8000 to 2400 rpm. Any help on this matter would be greatly appreciated. The one thing I will add is this, I have a lot more experience with using a router for carpentry, than on a CNC machine, and am not familiar with bits used in that application that have a similar function to those used on a CNC machine, though I will admit I'm not an expert in either, Thanks for any help.

[Kenny Duval]

Router bits are generally 2 flute and the cutting edge is not a Helix. Perfectly fie for soft materials like wood. Not so good for metal. They can be used in softer metals like aluminum but are not ideal. Your machining experience will be slow and unpleasant. They can be used if you have nothing else on hand but adjustments to DOC, WOC and feed rates will have to be made and they will all be significantly smaller than a comparable end mill.



End Mills are specifically designed for metals and have very different geometries to router bits for a reason. Plenty of places to get reasonable prices on them from Ebay to some where like Lathe inserts .com are worth having on hand if you will be working in metal occasionally.



Home Depot does carry a product that is very End Mill like and would be the best choice of anything you can get there for working in metal. Still not going to be a good as a proper End Mill but better than a router bit made specifically for wood.

Diablo 1/4 in. x 1 in. Carbide Up Spiral Router Bit-DR75102 - The Home Depot

[omegaguy]

Thanks for the input, will be working primarily in wood

[ger21]

If you need a .5 ballnose for wood, get a core box router bit. It'll be considerably cheaper, and work just as well.

[Jim Dawson]

You really need to match the tool bit to the job. I have successfully used solid carbide and carbide tipped router bits on the CNC milling machine for cutting everything from wood to stainless steel, on the other side I have successfully used solid carbide metal cutting end mills on a CNC router for cutting aluminum and plastics. When cutting wood products on the CNC router, I normally use solid carbide or carbide tipped bits designed for wood.

So it depends what material you are cutting. What burns the bit up is not enough feed for the spindle speed, so the bit is rubbing and not really cutting.

[omegaguy]

Thanks, had looked at that option, just the file I have calls for the .5 ball nose but if the core box is a valid option, that's the route I'll take

[MFchief]

By coincidence, yesterday I got an email promoting a new line of router bits by Freud specifically for CNC routers. Don't know if this is significant, or just marketing. They did show some unusual shapes for router bits, such as tapered bits. Might be worth checking out.

But if you are working in wood, routers bits will be fine, and almost always cheaper than the equivilant end mill.

Good Luck
Terry

[omegaguy]

Thanks, I'll check them out