Has anyone attempted to engrave and then cut gauge steel with their Shapeoko or X-Carve? I’m looking at engraving some plaques and then cutting them out of 18 gauge steel, just wondering if the machine can handle this before I buy one!
Not yet but I would assume you would research the bits first, along with the suggested feed and speed rate to ensure the highest chances of success. There is a second option, simply heat the metal up do not quench properly to weaken the steel then mill then heat treat and strengthen? Either way Ill let you know when I try it my self.
Ya kind of figured it would be fine. The bit would be a big part of it and just having a good feed rate. Cooling would probably have to be considered, if not going with the method you explained, which wouldn’t be to difficult to deal with.
Let me know how you fair, I haven’t been able to find anyone who has tried it yet.
You can, but you have to have a VERY small downfeed and need to ramp the spindle speed WAY down. I think officially non-ferrous metals are all that’s supported, but if you get some coolant on there and are prepared to have some REAAAAAAAAAALLY long run times, you can. You’ll need a carbide cutter, and forget using a dremel type spindle. One of the primary issues you will run into with the quiet cut spindle is that at slow speeds you are going to not really have enough power for the cutter, but at the higher speeds you’re putting too much heat into the bit… thus the need for coolant as normally the chips carry away most of the heat from the machining operation… but you don’t have the rigidity or power on a SO2 (or the X-Carve) to get a large enough chip… so it’s a balancing act.
Heat treating gauge steel is pointless. There isn’t enough carbon in it to heat treat / harden. It’s pretty much already as soft as it’s going to get so annealing it won’t do any good either.
You will be able to engrave it pretty easily, cut cutting it out after the fact is going to be your big issue. Likely unless you are planning on complex curves and the like (plaque implies to me something more akin to rectangle) just cut your steel with a separate process after it’s engraved to save time.
Take a look at this post on the Shapeoko forum:
He machined a block of stainless… which is FAR harder than sheet steel.
Clearly that post above shows it is possible. At the same time X-Carve is not designed to cut steel.
Thanks for all the input guys! I’ll probably process the sheet into the size of the plates I need and then engrave them, or vice versa.
Not going to lie I’m sure I’ll try and cut the sheet at least once, like come on 18 gauge is only 0.05 in thick.
Your idea of cutting the plates out first and then machining them on the desktop CNC is likely best. When you buy your stock, you very well may be able to have the supplier cut it down for you on a shear. Cutting metal stock is a science all unto itself, with far too many ways to skin that particular cat. When I’m cutting flat stock I like to use my “death metal cutting circular saw”… aka the Milwaukee metal cutting circular saw - 8" Metal Cutting Saw as it’s really unparalleled for slicking it’s way through flat stock, leaves a clean edge, and isn’t terribly pricey. Note, you can NOT just put a Milwaukee blade on a regular wood circular saw which spins, typically, at 6200rpm. You’d burn up the blade REALLY fast doing that! The Milwaukee runs at 3700rpm. You can slice through aluminum with a wood cutting blade at wood cutting speeds, but NOT steel!
Anyway… 
I think you’ll find that 50 thou to be much larger than you might think when machining steel on any desktop CNC. 
In the example URL of the machinist cube that he made, his roughing passes were 0.5mm and his finishing passes were 0.15mm (let’s see, that’s 0.019" and 0.005" respectively) and he was STILL breaking endmills and pushing his machine to it’s limits… I think part of that was he was using too many flutes (with smaller feeds, you want less flutes so you get a larger chip) but basically it can be done. Also note his machine has NEMA23 steppers, not the NEMA 17 motors that most of us have. All that said, he was machining stainless, so those feeds with a NEMA 17 and a 2 flute carbine endmill would likely be OK. I might feed a little slower and take a slightly smaller DOC, but that should get you into the rough ballpark of where to start from.
Also, just as an FYI: In machinist terms, 50 thousands is a barn door sized amount. Also note, when discussing machining -=TYPICALLY=- you will use something like 0.050" for standard and 1.27mm for metric measurements. Thousands are used in standard measurements as pretty much every machine tool is setup to work at at least that level of tolerance. For really accurate machining you’ll hear about working to “tenths” but this isn’t the 0.x00" but rather 0.000x (where x == the digit being discussed) so if somebody says they need to have part tolerance to “5 tenths” it’s 5 tenths of a thousandth of an inch.
I agree. I tried to slot 18ga. steel plate 1/8" wide x 3/4" long, by hand, with hand wheels, like using a milling machine. I placed stops on the X axis, and lowered the Z very little per pass. It took incredible amounts of cutting oil. I still managed to dull the 4 flute end mill. Although my Shapeoko 2 and DW660 were accurate, that’s way too much stress and oil for a nice wood, plastic, and soft metal mill. I would suggest to save and buy a used mill designed for that purpose.
http://www.harborfreight.com/two-speed-variable-bench-mill-drill-machine-44991.html
This will most likely the route I’ll go. The plate I’m looking to do will be rectangular, so It should be easy enough to cut them out before or after the fact if I’, looking at doing a larger nested run.
Thinking about it more I will have to be engraving stainless, so I’m hoping that a good engraving bit will still be up to the job.
P.S I’ll be purchasing an X-Carve 1000 with NEMA 23 stepper, hopefully that will be able to handle the majority of what I throw at it.