I’m considering cutting some 3mm thick letter out of brass. This would be the first time I’ve cut metal on my CNC (PwnCNC ATC, Onefinity Elite). If anyone has cut brass and could share some advice I’d appreciate it.
One thing I’m currently researching is lead free brass. It seems that most brass has some lead in it to make it easier to machine, but lead bits in my shop makes me uneasy. I hope to find some lead free brass.
What bit do you use for brass, and what thickness and speed do you cut with? I want to cut brass, but have no idea how to do it. How do you hold it to cut out letters? Information appreciated if you will share. Thank you.
Research is key so start here: ------->
Success! Tonight I made my first cuts in brass and I was very surprised that everything went well. After some polishing the letter H I cut looks great to me. The photo shows some of the fine scratches that I think I can buff out with some more time. However, this letter will be viewed from a minimum of two feet, at that distance I can’t see any scratches and it looks very shiny.
I feel like the depth of cut was too conservative. I also wonder if I could significantly improve the surface finish by adding leaving some material and adding a finishing pass. Improve the surface finish would be useful to me as I don’t know how to sand and polish the vertical edges.
Light cuts, preferably with a tool that has a corner radius. I like to spray or drip window cleaner as a coolant when doing metals. I’ve made a waterproof shallow milling tub with internal workholding so that I’m not slinging liquid all over the place. I used a deep dish rectangular baking pan, secured to a pc of mdf around the outside edges and glued down so the bottom doesn’t chatter. Form up some makeshift splashguards with aluminum foil if necessary, and you can get pretty sloppy without soaking your wasteboard. I’m just not a fan of using compressed air because I don’t want metal chips and slivers flying around.
