What bit to use for stainless steel...

[signgal]

Hi, routing enthusiasts. I'm proving the value of this forum to my partner/hubby who does the routing. :Big Laugh We have a Gerber Dimension router/engraver and a client would like us to surface etch a symbol on some stainless steel plates. Very small but a lot of plates. We were told in the beginning we needed a water system to engrave on metal but have had no problem this far.

So, I need a suggestion on a bit or if we should pass on the job.

Please and thank you!

 

[marcinito]

Stainless steel on CNC routers ? uhmm.
I've done some SS cutting on Multicam routers and will never do it again.
Engraving on the other hand may be possible.
Here is what I would do in your situation. I would call my tool supplier and ask for tool that can make this project happend. Check Onsrud website, send some emails with what you are looking for to people where you buy your cutters from. Chances are that if they do have something for you, they will ship it next day air.

Keep in mind the entire project. If this job will put plenty of abuse on your spindle will it be worth it ? I use to think cutting 1" acrylic with one pass 32k rpm was fun until my spindle give out.
How deep you plan on cutting/engreving ?

ps. if you find engraving tool for SS on CNC router don't forget to ask for reccomended feeds etc

 

[V-ENGRAVE]

Signgal,

If this is a small intricate symbol I would suggest laser etching with CerMark compound. Sub it out to laser equipped shop. The image would be permanent, durable black mark.
Since CerMark showed up as an alternate solution I never route out SS any more.

 

[CES020]

Or chemically etch it down into the metal.

 

[signgal]

He called the suppliers and it's like no one knows anything about what they sell anymore. frustrating... as i said it's only a surface etch. customer supplied a sample for us to try because he tried laser engraved and didn't like it. It's just an outline of an octagon, no biggy. Hubby tested out the sample and it turned out fine but they want alot of them and i'm worried about the wear and tear, like you suggest. Thanks very much for your input!

 

[CES020]

Your issue, depending on the machine you own, can be several, some you can overcome, some you can't.

What grade of stainless will it be? What diameter a cutter will be be? Cutters have to run as a certain speed or you'll burn them up. Also, stainless will "work harden" if it gets too hot. It'll actually heat treat it and it'll be so hard you can't cut it. There is a formula for figuring that speed out and it depends on your cutter. If it's carbide, it's roughly (3.82 x 200)/(diameter of cutter). That's a very conservative estimate. So if you have a 1/4" cutter, then it's 764/.25 =3,056 RPM.

Some routers won't go that low in speed. So trying to run it at 8,000 RPM will burn it all up and make bad things happen (possibly).

Maybe some cold air blowing on it through a air nozzle would help as well.

No reason you can't do it.

I wouldn't try cutting the perimeter too much though, for reasons mentioned above, plus it takes a ton of torque to cut stainless and if you are using a vacuum table, it's going to be tough.

Just my opinion.

 

[sauer_power]

My advice, (im a machinest by trade and vinyl is just my side job) woiuld be to go a local machine shop and explain what you are trying to do. I could offer some help but I dont have much back round in routing and with out know what grade stainless or how deep you plain to go I cant off much help. THe few thing I have had cnc cut for our shop we took a ball endmill and plunged in about .030" and just outlined the image. I have only dont this with aluminum and it has been many year since I last did it. The best think I can say for lube is to find a product called cool tool in a spray can. it can be bought here www.use-enco.com and just spray on the sheet by hand as its cutting. WD40 also works very well but only on aluminum, so thats no help.

 

[ActualGrafix]

Trying to CNC stainless steel is a bad idea. Stainless steel is very difficult to cut. Try cutting it with an oxy torch . . not gonna happen. Use cobalt bits and a lot of pressure at low rpms (maybe 1,000 rpm) and cool it down while cutting it . . . stainless does not dissipate heat very well, so all the heat goes into the bit.

Good luck

 

[signgal]

thanks... but we are NOT cutting it as I said. Only surface etch. very light. we haven't gotten the job yet. we'll see

 

[V-ENGRAVE]

For a very light surface marking I would use diamond drag on my machine.

 

[gbahue]

Third Party all the way. We send out all of our Stainless work and mark it up. We've tried to drill/cut/engrave and have found its better to have someone who has a stainless shop do the work. Also, make sure they won't use the same equipment as they use for steel. The particulate matter fuses on to the stainless and it can show small rust spots. Not cool. Im sure you can google more about this phenom. Send out and markup.

 

[rexsee]

I think routers aren't used for stainless sheets, it needs plasma cutters to cut stainless materials

 

[letterman7]

Geez gang, can't anyone read? She's not cutting the sheet, she's trying to etch it. I'm with the camp of sending it out to a specialist who deals with stainless. A diamond drag would work, but if you've already done a sample and it worked, I'd simply order a handful of whatever bit you used and add it to the final total for the sale. Keep it cool with a mist or coolant flood and roll with it. Why complicate things?