Cutting Brass Pieces

[tallen84]

I am working on a sign and I am wanting to cut some 0.02" thick Brass plate for some letters. The letters I am cutting are approximately 3" tall and I need a corner radius of about 1/8". Does anyone have any recommendations for the following?

1) What is a good bit for cutting brass?
2) What are some recommended spindle speeds and feed rates?
3) Can I do this with just one pass?
4) Is coolant needed?
5) Anything else I need to know about cutting metal?

any help would be appreciated. Thank you.

[bob_s]

just use the search function in the blue bar and enter "cutting brass"
lots of good info

[shoeshine]

Hey Todd,

I cut a ton of brass.

Go to a tooling shop (or online) and get bits made for machinining non-ferrous metal. They have a slightly different geometry than the wood bits we are all familiar with. I use Niagra Cutter 1/8" bits by the pack. Luckily they only run about $6 a pop.

I use a PC router and I run it @ 13k rpm, feed .03 -.05 ips, plunge .01 ips. The key is to ramp into every, and i mean every, cut.

My regular pass depths are .02 even for the thicker material I usualy cut, so I think you could do this in one go. Again, ramp into all cuts.

I use CRC thread cutting lubricant. It is nice viscous stuff in a spray can so you can just spray it on the sheet and go. No circulation needed. It does definately help. Cutting dry works, but eats bits and edge quality can suffer.

my only other tip is that tabs can be your best friend for hold down. Brass can be cut down to tabs of .005 -.01 deep (almost like foil) and .125 long depending your Z being accurate. They hold even tiny pieces in place and can be cut out with a utility knife.

Good luck,
and let us know how you do.

Chris

[tallen84]

I gave that a try however, I am having a problem with it creating burrs. Does anyone have any suggestions on how to either limit or eliminate burrs? Is there a special bitt I should use?

[Brady Watson]

Asking how to cut brass is like asking how to cut aluminum... One guy will cut it successfully while another will have problems - even using the same settings on identical hardware.

What alloy is it?

-B

[tallen84]

I am using alloy 260 with a reflective surface on one side. I am trying to cut this to act as decorative lettering on a sign I am working on.

Also, I spoke to Onsrud and asked them for their recommendation on how to improve the cut and they pointed me to their 63-606 bit. As a result I ordered one of those and will give it a try when I receive it.

[tallen84]

I just wanted to give everyone an update. I ended up using the bit I got from ONSRUD with fairly good results. I found that if I cut using the middle of cutter that It kept the burrs to a minimum (so for my 0.02" brass I cut at 0.08").

I also had an issue with keeping such thin sheet brass held down without pulling up and bending. I ended up using dozens of hold down points as well as following the router head with two boards, one in front and one behind the cutter to keep deflection and vibration down.

In the end the final pieces came out nice.

[meatbal80]

Did you also use vacuum hold down?

[knight_toolworks]

for really small pieces tabs may be needed. or what works well is to epoxy the material to some scrap. Epoxy does not stick well to brass. Then you can use a heat gun to warm them up and off they pop.

[oddcoach]

I have the widgetworks pressure foot and it works great for cutting thin material

[knight_toolworks]

I have the widgetworks pressure foot and it works great for cutting thin material

it's good too but if you don't have one. I have like the unlucky people out there then you need different methods.

[majohnson]

I would try cutters from Micro 100 or Harvey for top quality small cutter. Cut quailty has a lot to do with bits.

[tallen84]

Joel, I do not have a vacum hold down system so I had to make do without it. I imagine if I had one it would have been easier to cut the brass.


Also I wanted to share a quick photo of the finished product. The sign pictured here is a sign made to go on the side of a boat named "Turkey Salad". Note I had a hard time getting a good photograph since it was requested to be black and brass with very high gloss.

The sign body is made of high density urethane (HDU) foam with 0.02" thick brass letters. The entire sign was then clear coated and polished to a high shine.