cutters for engraving brass plate

[Stewey]

What is a decent cutter for engraving letters in brass?
I have tried the half-round solid carbide pointy engraving cuttersm and find they 'gunk up' and cease to cut cleanly quite quickly & burr the edges & then don't cut properly.

Should I be using fine end mills instead?

I have a 3.6 x 2.4 metre bed CNC router, but want to use 1/8" shank cutters for small engraving- like text around 1/4" tall or so, in brass & aluminium.

Any help is appreciated!

[LeeWay]

I was using mill drills to do some engraving on steel and aluminum. I learned how to sharpen these myself to get decent results. That is after the points get worn or chipped.
I still use mill drills when I have other operations to do with the same bit, but now when engraving or spotting, I just grind a drill bit. Probably not as good a solution for the smaller bits, but you should be able to use larger and grind them to a point like you need.

I use basically the same geometry as the original bit, but at a steeper angle like 82 or 90 degrees. HSS drill bits are less prone to chipping the points than carbide or cobalt especially using a router setup that may not be as rigid as a mill.

If the brass is clogging up your cutter, you may need to slow it way down on the spindle speed. I haven't done that much brass, but the little I have done was very easy. Better than aluminum actually.
You might also try air blasts while engraving to keep the point cool and the chips cleared. If you are using a router, it may be blowing air down already, but this is usually hot air after awhile.

[ka3rdf]

Hi, This is Steve. I'm new at this but I have heard a lot about the different alloys of brass that mill cleanly and those that are gooey and tend to be sticky when overheated. I have found that more copper in the alloy, the harder and easier to mill.

For what it's worth. Steve, ka3rdf@earthlink.net

[Stewey]

Thank you for that bit of advice- I'm still wondering what are the most appropriate cutter bits/router bits to use- an upcutting end mill, or an engraving cutter which does not have the upcut, but a straight half-round cut?

I appreciate the replies, though- thanks!

[cncwhiz]

Are you cutting dry? I would use kerosene on brass. Just wipe some on the top of the material. How deep are you cutting?

[keneuro]

you should not need to use any fluids on* engravers brass hss or carbide Dbit(engraving cutter) hard brass use carbide

[keneuro]

I have been engraving for 30 years I have never used any fluids are you milling even then I would not use fluids no need .speed of cutter around 1800rpm

[keneuro]

Hello Stewy what are you trying to engrave

[keneuro]

you will need to buy engraving cutters Dbits you can buy them off the shelf angle 20deg thats what I grind mine at what ever size tip you want smaller letters depiending on dept you may have to slow feed rate speed

[cncwhiz]

I can take what ever speed and feed that you cut dry with and produce a better finish on the letter with kerosene? You can cut lots of metal dry but for the "best" results I stand by what I am saying.

[keneuro]

Hello CNC WIZ I beleive you when you say you get great results when using kero. If it works for you use it, we all have own habits some things work for some not others do you paint fill letters how deep do you cut, what angle do you sharpen your cutters and how much clearance at back....Ken

[cncwhiz]

What kind of engraved letters do you want to talk about? I have been a machinist for over 30 years. I have made and still do in this shop make single line
engraved text. I do not use cutters for that with an angle, I use .025 ball end mills. If I was going to paint an letter I don't think I would be using brass? I have made block letters, logos etc and I always use store bought cutters. I am putting together a sign shops router and I would cut dry there but I am going to have him get an exair to keep the plastic from melting to the cutter? I am trying to get his old router for my garage. Depending on what I make or cut I might cut dry but I would always prefer to at least use a spray mist? I used to grind all my cutters and drills but time is money so I buy all my cutters of have them made.