Cutting State Map Outlines

[Briscoe]

Hello All,

I'm a relative beginner with CNC so hopefully you can help me with some tips. I want to cut some state map outlines using some wood approximately 5/8" thick. Any advice on the best bits (1/4" shank) to do this? Also, are there certain brands that are better than others?

Thanks for any suggestions.

[Adrian]

Two things to bear in mind is what diameter bit do you need to get into the detail on the edge of the maps and are they available with a depth that enable you to reach to the bottom of a 5/8" board without cutting out. You can work from there to see what is available.

[Rcnewcomb]

I'd recommend that you use a single-flute bit like an Onsrud 48-005.

[Briscoe]

Thanks, friend. I will check that one out.

[ezurick]

I'd recommend that you use a single-flute bit like an Onsrud 48-005.

May I ask why you recommend a single flute for cut out? I had thought that a double flute would give a better cut. In fact, the more flutes, the better imo. I am a newbie.. just asking for my learning.... thanks

[Adrian]

Problem with more flutes is getting the feed rates and rpm's correct to ensure that there is fresh material for each edge to cut. With mills where 4 flutes are common they run at much lower rpms.

[martin54]

Just to add to what Adrian has said if you are cutting something like a State outline then there will be a lot of changes in direction as the machine cuts so even though you may have set a fairly high feed rate the machine is never actually likely to get close to those speeds. Routers & high speed spindles can't be run slowly enough for some of the work that is needed so if you can't reduce the spindle speed or increase the feed rate then the next option is to reduce the number of flutes on the cutter

[Rcnewcomb]

I suggested a single flute end mill because smaller machines may not be able to move fast enough and/or reduce the router RPMs enough to get a good feed rate with a 2 flute bit.

A single flute bit has a much larger gullet for better chip disposal.


A tool with more flutes has less space for chip disposal. However, bits with more flutes are stronger. That is one of the reasons bits with 4 or 6 flutes are used in metal.

[dhellew2]

For a smoother cut i prefer a spiral 3-flute bit. The spiral maintains contact with the material being cut which reduces chatter. Dale

For anyone interested, the work has already been done for state outlines in layers.
viewtopic.php?f=27&t=30587&p=221011&hil ... ps#p221011

[ezurick]

Thanks for the info... that really helps when I am shopping for bits. I certainly had the wrong theory about the flutes and prolly explains why some of my cuts look like the bit is worn although it is new. thanks.