What type of metal can be cut/engraved on CNCRouterParts or FineLineAutomation CNC's?

[John Kleiber]

Hello everyone. Usually I post on the engravers forum. But this is about CNC's so here I am.

A little background, I own a small laser job shop. Currently the only tool style CNC I have is a Taig with Mach3 software. The machine at 10k rpm and a ridiculously small bed handles small aluminum engraving like a champ for the past 10 years and has paid for itself many times over. Now I have since added laser equipment the engraving that the Taig machine does now is rare and usually used for only small one up polymer engraving etc.

I've done a searches here and the internet in general to determine what type of metal I could cut or engrave with the CNC systems.


I emailed CNCRouterParts.com and await a reply.

FineLineAutomation.com has one paragraph on their website which says "To be clear, the size of the motor is not a indicator in what material you can cut. Both the NEMA 23 and NEMA 34 sizes will cut hardwoods, manufactured woods like plywood, plastics, aluminum and other non-ferrous materials like fiberglass, bronze, and brass. The ability to cut those materials are impacted much more by the rigidity of the machine and having the proper bits with the right feed rates."

I would like to know from a real world perceptive what metals and thicknesses others might be cutting with these machines.

Usually someone on the forum will ask what type metal I would like to cut.

Aluminum would be one type of material easily cut based on my Taig. But if a customer wants a custom panel cut out of a 16 gauge piece of brushed stainless, is it doable with of coarse the right tool, feed rate and coolant?

Thanks
John

[William Adams]

Cutting metal with a CNC router is quite a bit different than doing it with a "real" mill (or even a small one such as your Taig) --- you're trying to use RPMs/speed rather than torque to get a chip, which means that rubbing and heat buildup become much more of an issue, and since the machines can't be as rigid as real mills, it's difficult to get a nice finish.

That said, with the right selection of tooling, feeds, speeds, and if need be coolant, one can cut non-ferrous metals pretty easily --- even steel can be cut, albeit at a likely high cost in tooling (even carbide won't survive long), but depending on the alloy, stainless can be very tough stuff and might be out of reach.

The best thing to do is to puzzle out the appropriate feeds and speeds for the material in question on the machine you'd like to use using a calculator --- the CNC Cookbook one is very configurable and most people who try to learn to use it are successful with it.

[Bruce Page]

I don't have any hands-on with the two CNC's you mentioned but with the proper feeds/speeds, coolant and tooling you could probably cut 16ga SS if you are patient. That said, I do know I wouldn't do it on my Camaster Stinger. Most any CNC router manufacturer will approve of cutting aluminum, brass, bronze, etc. I've never seen that approval given for steels.
IMO, you would be better off to sub out the occasional walk-in job to someone with a beefy CO2 laser.

[John Kleiber]

William and Bill, thank you for the posts. Since I started this thread I have come to the same conclusion and your input helps me to know I am on the right track.

Currently I take material I need sheared or laser cut to a shop near by. That works well, but I was basically trying to determine if I received an order for light cutting 1 up or 3-4 piece jobs would be possible. Also I was interested in light text engraving on stainless which I think is realistic under certain conditions, but I need to read further on that.

Yesterday I received a response from CNCRouterParts which included a couple videos routing aluminum like butter.

Now that I have a better idea of the material possible, I can better forecast its money making possibilities.



Thanks again, John

[Robert Bonenfant]

Hey John,

I would recommend having them do a sample part and get the times it takes to complete the item. The video you showed is cool but required alot of prep and and they dont give you a real estimate on time. My cnc could cut metal (4x8 Smartshop2) but we find most jobs are more profitable if we sub them out to a local shop. The local shop we use to mill/ cut metal uses Haas Milling Machines (Not sure the model they have several). They clamp the metal in a quick clamp and the machines off running - It doesnt take them much time to swap out parts (From what i seen the few times I was able to watch the work in progress).

Im not saying a cnc router wouldn't be the way to go but time is money. My laser rep says my machines can cut 1" Wood - In truth it can but it would take forever. I tested a simple 24" crown 3/4" plywood - Laser - 8 Minute run time . Cnc - 49 seconds run time. My main point is get some testing done before pulling the trigger on a new machine. Sales reps love to tell you what you want to hear but in reality everything has limitations. Please keep us updated on this - If you do move forward would really like to see what your machine is able to do.

[John Kleiber]

All,

I sent an email to CNCRouterparts with a timing question regarding the following video;



Lets see what they say.

As you guys stated, its probably more cost effective to sub out the cutting if stainless steel for large jobs. However I did inquire about the possibility of minor cutting of 1 mm stainless and direct routing of labels to the stainless.

I have no formal training as a machinist. I only know the little bit my dad taught me before he passed. Please excuse my weird way of figuring things out.

Thanks
John

[John Kleiber]

I received a reply at the end of the day yesterday from Ahren at CNCRouterParts regarding timing and possibility of minor cutting of 1 mm stainless and direct routing of labels to the stainless.

Ahren said cutting stainless can be very difficult, not so much because of the machine but because of the required rotational speed for this material, which is typically in the hundreds of RPM rather than the 8000-24000 that most CNC router spindles provide. Engraving should be possible, but you may need a custom spindle arrangement to cut through it effectively.

In terms of the videos, he does not have the actual run times for these close at hand, but the cutting on the 1/4" part was at 300 ipm at a 0.050" depth of cut.

I am a little lost when he says custom spindle arrangement. I suppose he's talking about buying a spindle mount and in turn installed a slower rpm motor.

-John

[Bruce Page]

He might be talking about spindle type. My HSD spindle can be dialed down to ~ 3 hertz, although I doubt there's very much torque at that speed. It runs much better at 14 hertz, but a sharp cutter and patience would be needed. 14 hertz is about what I run my mill at when I machine SS.

[Mark Bolton]

Id have a hard time believing that you wouldnt have endless trouble with work hardening stainless at router speeds. Most spindles dont hit anywhere near their rated HP until 8-10k rpms. I can run at 1600 but not with enough power to mill any sort of metal at that speed.

Beyond that, the part in the video could be milled in seconds or perhaps a minute or two on a low end cnc mill like a tormach. You may look into Tormach type machines for what your trying to do.

[John Kleiber]

I visited Tormachs website, but their work surface is too small. I want to be able to engrave and cut plastic and aluminum sheet stock for name tags, id plates, control panels, etc. as well.

I've pretty much concluded that cutting or shearing stainless steel is best left to sub out as I do now. However, once I had the stainless cut to size, I at least wanted handle the stainless engraving in-house.

-John