Routing aluminum

[Victor Robinson]

So I've been thinking a lot about machining (mainly routing) aluminum lately. My purposes would be mostly for jig-making, and material would be no thicker than 1/4"-3/8". Just wondering about best practices for using carbide router bits on aluminum for cutting slots, and minor edge profiling like chamfers and roundovers.

As I was doing some video research, I came across this video. I plan to do it exactly like this unless I hear otherwise from you guys. :eek:

https://www.youtube.com/watch?v=8lMQmJy2VW0

[Al Launier]

With the bushing that will certainly help minimize the chance of the cutter "digging" in. However, I think you are really flirting with danger, especially by wearing gloves, and a loose fitting one at that. Aluminum is a soft material & has a tendency to grab. That is why drill bits are "prepped" for drilling aluminum (and brass) by grinding the cutting edge to a slight flat, to prevent/minimize the drill from grabbing as it exits the hole.
If you "have" to do it this way and although the demo produces a good result, i would rather see you fixture up the process by having a couple of steel dowels inserted in a horizontal plate, position the router fence for smaller incremental cuts (not all at once) & bear the aluminum ring against the dowels while rotating into the router bit. Reposition for the hole with the router bit inside the hole.

[Peter Kelly]

Where to even begin with that video...

[Peter Kelly]

https://www.youtube.com/watch?v=sjbamgq8FmE

[Dan Hintz]

https://www.youtube.com/watch?v=8lMQmJy2VW0

I just got chills watching that, and I noticed afterwards my fingers had curled into a fist in anticipation of a catch...

[glenn bradley]

Visit Pat Warner's site. He mills aluminum frequently and sometimes posts here. You could PM him.

[Mike Cutler]

Victor

You can work aluminum with a router. I can't say that I recommend to do it like that video though. At least make one of the variables fixed. Either clamp the work piece down, or secure the router. That's all I'll say about the video.
A speed controller can be used on a router without a soft start, which allows you to control bit speed. Something to consider when working with aluminum or other soft metals.
There are some milling machine bits that can for into a router. I have a few of the more basic types for soft metals, and they work okay. When I've use them, I dropped the speed way down on the router. ( I have an ancient craftsman router that I use. )

I've only used a router on metal a few times. Which is why I've been looking at some of the smaller bench top mini milling machines to do specifically what you want to do. That is, make small jigs and fixtures for wood working.
The mini mills are probably all but worthless to a real machinist, but to make soft metal jigs and fixtures for woodworking, they look okay. There are also a few websites dedicated to "souping them up" and provide aftermarket parts and upgrades to them to make them more reliable.
Me personally, I'd rather have the tool that is supposed to perform the function, if I can.

[pat warner]

"I just got chills watching that, and I noticed afterwards my fingers had curled into a fist in anticipation of a catch..."
************************************************** ***********************
In total agreement with that.

[ian maybury]

Eyyyyyeuuuw! I wouldn't ever want to rout wood that way, never mind aluminium. If the bit bites it won't even register in his awareness until well after it's cut a chamfer through his finger(s) - gloves, nail, bone, everything. Next moment he'll be looking at a pool of blood on the floor and feeling faint. That's if he's lucky enough that the glove doesn't get wrapped up in the router and really do a job on his fingers. A circular part is nearly the worst of all because it's so hard to get a grip on/prevent it rotating, and your fingers are right in the line of cut if that happens.

A router will in certain circumstances cut aluminium, but it's for safety reasons way outside the recommendations of just about any equipment manufacturer and very much at the users own risk. I'm not even going to describe a possible set up out of concern that it might be read as advice….

[Larry Fox]

Where to even begin with that video...

I got 30 seconds into it and had to close the link. That just might be the most unsafe thing I have ever seen anyone do. When I first saw it I thought there was no way the router could be turned on but it appears to be.

[Jeff Ramsey]

This guy's cat is smarter than he is, in the video. What a dumb thing to do.

[Bill White]

Death wish!!!!
Just shows ta go ya that there are stupid people everywhere. He'll probably want to sue the router manufacturer when he gets his hands chewed off.
Bill

[Ole Anderson]

The first video was just plain stupid unsafe in so many ways. Maybe using a router table and with the ring secured in a jig while using body and face protection. The second video was OK presuming the router was secured to the table.

[Jim German]

As others have said that video is impressively unsafe.

That being said you could use a router on aluminum without it being to big an issue if you can slow the router down significantly, an rigidly hold the parts involved.

[Jon McElwain]

I plan to do it exactly like this unless I hear otherwise from you guys. :eek:


Yeah, don't do that!

[ken masoumi]

I plan to do it exactly like this unless I hear otherwise from you guys. :eek:


Am I the only one who knows for sure you were kidding?

[Victor Robinson]

I got 30 seconds into it and had to close the link. That just might be the most unsafe thing I have ever seen anyone do. When I first saw it I thought there was no way the router could be turned on but it appears to be.

Soooo...you're saying not to do it like that?

[Brian Tax]

Wow! That is ballsy or stupid, probably both.

[johnny means]

And exactly what do you fellas think that 16th" of exposed cutter is going to do? You think his leather glove along with his hand and forearm are going to get wrapped around the router bit? Slicing carrots probably carries a greater exposure. I've been using a very similar technique on small parts for years, though I prefer to stand my router up on end. The scariest moment to me was when he walks away and the router starts walking towards the floor. Really understanding then respecting tools and material will go a long way in keeping you safe.

[John McClanahan]

I would never dream of cutting aluminum with a wood blade on a table saw. Then I saw a video of it in action, so I tried it myself. With care it works surprisingly well. This is the same way. I would have never tried this before watching this video. I would never use his setup, but for small round overs, I don't see what the big problem it is. After all, he has already shown what will happen.


John

[Mike Cutler]

We all have to do things outside the box at times. Yes, in this instance he only has a small amount of bit exposed, so any potential for damage is limited by physical dimensions of the variables involved.
It is the video as a composite that is a disaster. Loose router, both hands close to the bit, cats running around in the background, poor ergonomic position, etc. Worse yet, is that someone less skilled, or knowledgable, will try to emulate it.

As Johnny stated ;
Understanding and respecting tools, and materials, does go a long way to keeping you safe,. I'll add to that,using the right tool, for the right job, in the manner it was intended to be used, will go further.

Some things are just wrong. No matter how safe we can make it to do them.

[John McClanahan]

If you are interested in knowing more about how well router bits work when cutting aluminum, you might like this video.

https://www.youtube.com/watch?v=WQpEoDUhxBw


John

[pat warner]

If you like chatter and tears, this is the one to watch.

[Edward Oleen]

The guy is a freaking idiot.

The ONLY way to even start to do that safely is to have the router mounted in a table. Secondly, I'd make a jig to hold the piece so that my hands were a safe distance away - like a foot or so on either side.

Thirdly I'd want some sort of a SHIELD between any part of me and the work. That includes all the space behind the tool: loose work pieces can and will wind up in the strangest places, and break the strangest things, like windows...

I noticed the cat walking in. Ghastly: an animal disturbing you and breaking your concentration on your work is... NOT ADVISABLE. I have informed my wife and kid in no uncertain terms that if a tool is running DO NOT DISTURB ME FOR ANYTHING, INCLUDING WW-III.

Dust collection: fine metal particles can catch fire if too hot, and can and will conduct electricity: Al chips in the motor will not be a GOOD THING, in my opinion.

[steven c newman]

I wonder what sort of bits a CNC would use in something like this? CNC is just a computer controlled router, after all....

[ian maybury]

The very high risk of a gory accident in routing aluminium by hand as shown in the video is nothing to do with whether or not the material can be cut using a router….

I'm no expert, but (presuming a safe method is in use) the reliably clean machining of aluminium requires very sharp cutters with lots more rake and helix angle than for steel (or on a router cutter), lubrication, and correct (high) speeds and (more moderate) feeds. It varies quite a bit in its needs/ease of machining depending on silicon content, alloy and heat treatment. The big problem is to get the chips clear of the cutting area, and to prevent them being hammered into the cutting edge.

At one level it's easy and flatters to deceive (the cutting forces are low, but still much higher than wood), and it's less likely on light cuts - but to keep on cutting without running into compaction/build up of material on the cutting edge isn't easy. When that (potentially suddenly) happens then the tool stops cutting properly and starts trying to tear out material - with who knows what sort of grabbing or snatching effects.

The likely problem with a router cutter (hand held type) is that while it will clearly cut aluminium the angles are not even close to being optimised for aluminium. Hand feeding means that there's no real control of feed rate either. I'm not sure I'd want my router motor to suck in a load of (conducting/short inducing/bearing jamming) aluminium flakes .... There are 'router cutters' available for cutting aluminium, but they seem to be aimed at CNC rigs. e.g. http://www.trenddirectuk.com/50-08x8mmhsse.html (look at the pic showing the machine)

Most Euro sliding table saw makers offer their product for cutting plastics and aluminium as well as wood (e.g. http://www.altendorf.de/en/products/wa-80.html https://www.youtube.com/watch?v=icTh4cd5Ytg ) - with a correctly selected non ferrous blade on. Usually with adaptations like a mist lubricant spray. They work fine, and since the work is clamped and the user well away they are pretty safe. I've with care and a non ferrous blade cut aluminium many times on mine (using spray on lubricant on the blade and taking light cuts) without problems. It's reportedly possible though for a build up of hot chips to melt through dust collection hoses if too much is done too fast, and it's a PIA as the aluminium flakes go everywhere....

[John Lifer]

Wow, did anyone else give a thumbs down on that video? If not please go back and do so!!!!!!!!
I've routed and and sawn aluminum and it is not that hard. Just a lot of hard chips that go everywhere. Eye protection!

Wait, you Can report as unsafe, probably won't matter but it makes me cringe!

[Mike Heidrick]

I wonder what sort of bits a CNC would use in something like this? CNC is just a computer controlled router, after all....

TONS of different CNC machine out there - not all are routers for sure

I like an O-flute bit if I am using my cnc controlled router (actually use a 2.2kw spindle with an ER20 collet) - these machines are typical designed for working with wood and plastic and work ok for non ferrous metal like alum if built solid enough

I use endmills with my cnc mill - a true mill is designed to work with ferrous metal like steel and much more than a router in the speeds and rigidness of the headstock. Just the collet holder and bit is 1/2 the size of a whole Bosh Colt for example and the machine is 4500lbs.

They make bits/cutters for both machines to cut aluminum specifically

Also for woodworking saws I want a non ferrous blade with a triple chip grind to cut alum. You can do it with a regular carbide blade but watch for galling.

Also use coolant to reduce galling and keep the chips out of the kerf if you are cutting aluminum. Another thing I like to do with my cnc is leave a slight offset amount in the toolpath on the depth of cut and take a final finish pass at full depth to make a perfect mirror smooth final cut on my piece.

[Joe Hollis]

I've worked in the workplace health & safety field for 23 years, and have investigated around 40 amputation injuries, 2/3rds of which occurred in woodworking shops. as has been amply stated already, it's difficult to understand how anyone could think performing that task in that manner would be acceptable, hobby or not. I've machined aluminum with both my table saw (with a negative hook saw blade) and a router on a few occasions. I would only do it again if I had to. It makes a mess and puts aluminum chips everywhere, but it certainly can be done, and done safely with some forethought and the correct tools.

Joe

[pat warner]

Do it every day with this fixturing (http://patwarner.com/images/new_router_table2.jpg) and semi-ordinary cutters.
But I did not walk up to it one afternoon, cobble the components and ace out the cuts.
It can, however, be done with ordinary woodworking tools, safely, & without getting chip blasted.
And with the squareness and parallelism of a mill.

[Mike Cutler]

Pat

What speed, in rpm, do you estimate the bit is turning with your setup?
That's a nice setup. Very clean.

[mike mcilroy]

I just got chills watching that, and I noticed afterwards my fingers had curled into a fist in anticipation of a catch...

+1
I was freaking out just watching the router bounce on the stool let alone anyone getting near it.

[mike mcilroy]

And exactly what do you fellas think that 16th" of exposed cutter is going to do?
Its not just the amount protruding out from the base its the space between the bit and base, his ungloved finger could be pulled into the space between the bit and base, and so could his gloved fingers. That rotating bit will pull your finger in not just graze it.
1/16th off your finger if you were lucky enough to just touch the bit and be able to pull it back would be nasty enough to keep me from risking it.

[pat warner]

22,000 rpm.