DIY CNC 017 - Cutting Aluminium Upgrades

[@thehardwareguy]

Join Discord: discord.com/invite/QsC6AE8

[@GDub1958]

Awesome Project. You are really getting it, WOW! I first have had to learn using 3D design software. Started with Fusion 360 back when student license was offered. When that stopped I switched to FreeCAD. I first thought after I got enough experience I would buy a 3D printer but now I use my local maker space at my library. I have designed a small 1.5 to 2hp 48" belt bench grinder, and will send it out to an online fabrication shop to cut my parts.These shops are a one stop shop i.e. material, hardware, fasteners, etc the just I will just need to supply the motor and belt. I crunched the numbers and the price is so competitive, oh yes they have free shipping, too! I think you should be really proud of your accomplishments so far! SideNote: i am adding a lean-to room onto the side of my garage, for addition CNC projects so I recreated my garage building framing in FreeCAD and have designed the room addition accordingly. It is really a confident builder to design in FreeCAD then have the ability to create the dimensions needed for cutting my actual lumber, and it fits! Thanks for sharing! G_Dub

[@Luaghs]

For machining aluminium, i have found parafin a great cutting lubricant. I have 40 years experience as a toolmaker. So I'm not talking out my rear 😊

[@thehardwareguy]

Thanks for sharing, I will absolutely give that a go!

[@Robert-Holland]

Great what you are doing and that you share that with us.

[@thehardwareguy]

My pleasure!

[@louiel8711]

Use the shortest endmill you can for your cut depth keeps down the chatter and reduces tool deflection. Also if someone is going to cut alot of metal buying quality bits saves so much time

[@moki123g]

Agree, you will need to adjust your chip blower, but you want the bit as close to the spindle as possible and as short as possible. Search for something called a fog buster. You need to have a little lube when cutting aluminum.

[@thehardwareguy]

I checked out the Fog Buster, very cool and versatile piece of kit!

[@michaelkaastrup5429]

Hi mate. Great video and great CNC build. I wonder, how slow can you run your 2.2Kw spindle and cut metal's without the spindle heats up ?

[@Ryxxi_makes]

what is the recommended surface speed for Aluminium ? can you just put this and the tool info into fusion and have it calculate the spindle rpm ? Am a bit confised.

[@thehardwareguy]

It varies depending on your setup and who you ask, my advice would be to use the recommendation for the bit that you'll be cutting with. Yes Fusion 360 will calculate a lot of it for you, but don't compeltely trust it. Get a feel for it!

[@felipenavas]

Alcohol (Ethanol and IPA) is commonly used as coolant

[@thehardwareguy]

I've been reading about that too! seems to work well as it leaves the chips dry when it evaporates

[@axelSixtySix]

First, thanks for bringing calculations into the discussion; it’s rare to see this in hobbyist circles. "I keep parameters low" = My machine lacks the structural integrity and component strength needed to mill aluminum properly. It’s important to understand this. "The more flutes your bit has, the faster..." This isn’t totally true because more flutes reduce the chip size, which is an RPM vs. chip size trade-off. You’re going faster because your machine can’t handle the full chip load of a single-flute bit. Clogging comes from friction-too much heat due to parameters that are too low. The speed is too high, the chip load too low, causing the bit to overheat itself and the material. This affects cut quality, dulls the bit quickly, and increases wear on the machine's components, especially guides and transmission. And you can see it: you’re making aluminum dust, not chips. The bit requirements are the key factor. Everything starts from the bit, including the whole machine design: I want to do that job with that bit. What spindle requirements, component strength, and structural integrity are needed? Design around the biggest bit and the toughest job you want your machine to handle; this will dictate everything around the bit, from the spindle to the power cord. Always set parameters according to the bit's requirements. Don’t reduce them just because your machine can’t handle it: use a smaller bit instead. A smaller bit requires less power and generates less resistance. Light-duty machines can still do lighter work. Use common sense: see what kind of machines people use to mill aluminum and ask yourself, does yours look like that? Is its budget comparable to proper milling machines? There’s no magic here. If manufacturers could cut costs on aluminum milling machines, they would. If they use expensive components and heavy structures, it’s because it’s necessary! Your machine is perfect for wood, foam, plastics, and composites-materials gantry machines are meant to handle. It might manage very occasional light engraving or milling in softer metals like brass or copper. You don’t need to be Einstein to see that thick aluminum milling, day in and day out, is beyond its capabilities. Definitely. And don’t be misled by KZbinrs showing steel and aluminum cuts on budget machines; poor cut quality means the machine and bit are suffering and won’t last. Once again, they're making aluminum dust, not chips. Milling metal on a budget is a dream unless you’re a master at reclaiming parts, as components aren’t cheap. The structure might be affordable; you could mold a concrete frame inexpensively. But it shouldn’t be a gantry-style machine. Metal milling machines don’t look like that for a reason. There’s no universal machine: lasers and 3D printers should be light and fast, while metal milling machines need strength and weight. Machines claiming to do a variety of tasks often do none of them well. Just follow the proven designs of reputable manufacturers for machines that are up to the task. My goal isn’t to criticize the work you've done-it’s impressive for a hobbyist. But your machine isn’t built for milling metal, aside from brass, which is still a great achievement. Avoid falling into the upgrade spiral: investing in V2, V4, V15 of the same type of machine that will never meet your metalworking needs, when your current machine already does a great job with lighter materials. A dedicated DIY mini milling machine or a second-hand milling machine you can digitize is likely a much wiser investment. Just my two cents.

[@thehardwareguy]

Thank you for the thorough feedback-I appreciate you taking the time to comment. My goal with this machine has always been to create a versatile hobby setup that I could occasionally push into light metals like aluminum. I do believe my machine will get you further than off-the shelf hobby machines, at a lower cost. However, I’m fully in agreement that it lacks the robustness and high-powered components needed for serious, day-in, day-out metal milling. There's a reason those indistrial machines cost tens of thousands. 95% of my machine use is milling hard woods, other 5% is occasional aluminium project parts. It's perfect for me! I kept my parameters conservative due to lack of experience, you've got to start somewhere so it might as well be in the safezone. And yes, that means compromises-like occasionally producing dust rather than proper chips. But for my purposes, I accept these limitations; the intent was always to occasionally try my hand at metal with realistic expectations about its capabilities. Your advice on bit selection, chip load, and machine requirements is spot-on. While I know it isn’t a heavy-duty milling setup, I’ve truly enjoyed the learning process and the challenge of optimizing it within reason. Thank you again for the honest insight!