CNC specific bits

[Steve Stram]

I tried the search function for the site, but "cnc" and "bits" are too general. Adding best, alternative, size... only makes it more confusing.


I am looking at a design where I need to route 1" to 1 1/2" solid wood, probably Ash, Cherry and soft Maple. My dream would be a 1/4" diameter bit capable of 1 1/2" cutting depth. A 1/2" shank would be preferred. I'm not too concerned with the number of passes at this point.

Cutting will be on Shopbot Buddy with 4 hp spindle. On the Shobot site they seem to prefer Onsrud, but the 1/4" is only 5/8" cutting length.

I've used mostly Whiteside bits to now, but have others. The Whiteside RU 4700 is working for me, but is only rated for 1" cutting length. I don't have any metric ER collets for metric shanks. I do have 1/4" and 1/2" shank collets.

My thought is that are probably bits made for CNC that can cut deeper than those sold for router tables and hand held routers.

Anyone have a suggestion"

Steve.

[bobby milam]

If you don't find any maybe check with a local machinist and have him make you one. I know of people that get all of their bits made locally. I have a friend going to night school learning mills. I am trying to get him to find a student to make me some.

[Keith Outten]

Whiteside 1/4" dia 1.25" depth upcut spiral bit #RU 4700 $20.00

If you have to have 1.5" you can look at end mills which are often less expensive than router bits and more precise. End mills are available in more sizes and shapes that you can imagine. If you get a 3/8" collet for your machine you will find an even better selection of end mills available and a 1.5" spiral end mill with a 3/8" shank is easy to find.

The best of the best solid carbide router bits are from Centurian Tools in Louisa County Virginia. Centurian Tools started out making cutters for metal working machines and several years ago added router bits to their products. They often attend the ShopBot Camps here in our area showing off their bits which are so sharp nothing I have ever seen compares but they are a bit pricey.
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[Roy Nielsen]

I bought some end mills from cuttingtoolsource_com, they do have some extra length bits. Not sure about 1/4 cutting dia & 1/2 shank dia, although they can do custom.

[Gene Crain]

you don't need a cutting edge length longer that .625 to cut the 1.5" depth. I use a 6mm x 75mm bit with a 18mm doc and have no problems cutting up to 2.25" solid woods.

[Steve Stram]

you don't need a cutting edge length longer that .625 to cut the 1.5" depth. I use a 6mm x 75mm bit with a 18mm doc and have no problems cutting up to 2.25" solid woods.

I had thought about that at one time. Since the CNC is moving and on the path in several steps to the finish depth, the distance of the cutting flutes isn't as critical. It would just have to be that the shank not be larger than the cutting diameter. So if I used a 1/4" shank I could go much deeper than the specification.

I used to have a Kress router motor with metric collets, but the rear bearing spun in the housing.
Steve.

[Paul Phillips]

Steve, the only problem with using a specialty long length bit like that is they tend to cost a lot more and you usually have to run them at a slower feed rate, if you can use a larger diameter bit to do the rough work and then use the long bit to just clean-up the corners you can sometimes get the job done much faster, not sure exactly what you are doing but maybe that will help.



The best of the best solid carbide router bits are from Centurian Tools in Louisa County Virginia. Centurian Tools started out making cutters for metal working machines and several years ago added router bits to their products. They often attend the ShopBot Camps here in our area showing off their bits which are so sharp nothing I have ever seen compares but they are a bit pricey.
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Wow Keith, that's quite a claim considering the number of bit manufacturers there are, I've had great luck with Onsrud and really like their variety but I will definitely give them a try
Paul.