Tools - routing aluminum

[tunghaichuan]

I have chassis punches for holes up to 1&1/8", and am too cheap to buy anything bigger.

I've gotten good results using a laminate trimmer and a flush cutting bit. Most routers are too big. To make a pattern I use a spade bit, chucked in a drill press. I bore a hole in 3/4" MDF for the size I need. A cap can, for example, I use a 1&3/8" spade bit. First I hog out as much of the hole as possible using a Greenlee chassis punch. Then I stick the pattern down concentric with the hole using double sided carpet tape. I then use the flush cutting bit to follow the pattern and route out the rest of the hole. This also works well for IEC inlet cut outs if you can make an appropriate sized pattern.

Note: you can only do this with aluminum, I wouldn't try it with a steel chassis.

[lowell]

It's too damn laborious y'all! I'm too lazy for this haha. I am trying to make a few of these prototypes and am not going to go this route. Gonna see if I can find 1 3/8 punch and 1 3/4. I guess maybe there are metal hole saw bits or even carbon steel spade bits that big? And yes, IEC holes suck too. I drilled small holes at edge of pattern, then drilled as big as I could in the center, then broke off the edge pieces with pliers and cleaned up with barrel sander and file. I also have a hack blade in my jig saw which can help for square holes.

[J M Fahey]

I do own the needed set of Greenlee type punches but my home/shop is a hoarder's nightmare, so when I needed to make a custom job short ago and didn't find them in time, I bought octal and noval sized Starrett "Bimetal" hole/cup saws with the corresponding holders and guide bits.

They are *made* for steel, so aluminum is a joke for them, as well as plastics, Formica, acrylic, brass, copper, regular wood or MDF.

Just lubricate the metals and go slow with non metals.

Hole edge is slightly irregular (hey, it's been sawed off, not punched or scissor cut) but very acceptable, since it's uniform all around.

If aluminum sheet, which is soft and flows easily, clamp it to some spare MDF first.

The key to a clean cut is that the saw is steady and that depends on keeping the guiding drill steady.
And lubricate generously, on aluminum I do not use oil (too messy) but either wax/hard paraffin/soap or the opposite: kerosene (known as paraffin in UK)

The solid lubricants "stay there" , the kerosene flies everywhere but can be mostly wiped off and the rest evaporates with no residue.

Oil flies everywhere, never evaporates, attracts dust and lint and must be removed with some solvent (gasoline if nothing else is available) or warm water and detergent.
Better avoid it.

[lowell]

Awesome. That looks wrist and elbow-sparing. 😉😅

[jbltwin1]

As an added tip, if you need to expand an already punched hole bigger with a hole saw, center a piece of wood over the existing hole and drill through the wood AND the chassis. To me, that's easier than using the router, and I have ALL that stuff. I AM lazy though and usually look for the easiest way. Mike.

PS-to center it. I drill a 1/8" hole in a piece of scrap sheetmetal or wood and center THAT under the hole. Drill a 1/8" hole in the top piece, Line them up, clamp them and chuck it in the drill press. Nice and centered and I can pretty much hold my beer while I'm doing it!

[lowell]

Thanks, good tip.

[catalin gramada]

The only one drill which works for big holes in metal sheet is this type :
You will need a good, sturdy jig. Small turn ratio and well lubrication helps you for a neat professional looks like hole
Otherwise a file is all you need. This one was made by me in steel, a long time ago, believe it or not,with a file ...and a lott of cigaretes.

[Shadrock2]

I haven't heard anyone mention the "Nibbler" Tool [URL="http://www.parts-express.com/nickel-plated-nibbling-tool--360-022/"URL] which works well for aluminum chassis and particularly for non round holes such as IEC power connectors.


I'll second those hole saws. They make short work of larger holes in aluminum and brass. They work pretty well in mild steel if you lube well and don't try to go to fast. They are just about as expensive as the Greenlee punches though.

I've read that bacon grease makes a great cutting lube, must smell wonderful when in use, will have to give it a try sometime. Bacon, bacon, I smell bacon! One caution: might be a problem if you have pets... I can imagine little Fluffy or ol' Rover licking a freshly drilled bacon-scented chassis yum!

The traditional metal cutting lube was "Lard Oil" because it is very sticky which kept it on the cutting edge. "Duck Grease" works about the best for that since it seems to be the stickiest of all.

[J M Fahey]

I haven't heard anyone mention the "Nibbler" Tool [URL="http://www.parts-express.com/nickel-plated-nibbling-tool--360-022/"URL] which works well for aluminum chassis and particularly for non round holes such as IEC power connectors.


I'll second those hole saws. They make short work of larger holes in aluminum and brass. They work pretty well in mild steel if you lube well and don't try to go to fast. They are just about as expensive as the Greenlee punches though.



The traditional metal cutting lube was "Lard Oil" because it is very sticky which kept it on the cutting edge. "Duck Grease" works about the best for that since it seems to be the stickiest of all.

Nibblers are killer but I thought they were a thing of the past.

As of odd lubes, I use aluminum chassis exclusively and cut/punch/bend it at home, but on occassions I had to make many of some model I subcontracted them.

Metalworkers in general love iron and hate aluminum because it "sticks" to punching tools, but the universal cure around here is to use rendered *pig* fat , rather than any modern fancy lube, go figure.

[Justin Thomas]

Nibblers are killer but I thought they were a thing of the past..
.

I just bought one last year, and kicked myself for waiting so long! I too am of the filing camp, but without the cigarettes... Aluminum is AWESOME! Fender steel not so bad. And only one person ever got a stainless steel faceplate...

Justin

[lowell]

Just ordered the nibbler. Thanks! Also got the Roto XB-DC1 and the Dremel 562 tile cutting bit. I'll report back.

[defaced]

Looks like I'm a little late to the thread, but here's my experience. The problem with grinding, sanding or filing aluminum with tools intended for steel or wood is that the comparatively soft aluminum clogs the tool you're using. Aluminum burrs (google those terms) solve this problem by being very coarse. Unless you have access to compressed air, you'll want an electric die grinder too. Safety glasses and a face shield are required. You'll be showering in slivers of aluminum. You can buy the bits from mcmaster.com or any industrial warehouse (probably eBay too). Electric die grinder from Harbor Freight. You can also buy files for aluminum if you need them.

Also, if you have a wood router, those work very well on aluminum. You'll need templates, but aluminum is soft enough, and the bits coarse enough, to make short work of the sheet you're cutting. Same with circular saws. I spent several weeks of an engineering internship out in the July sun of Ohio cutting 1" to 2" thick 5083, 2195, and 2519 aluminum plate with nothing more than a marker, t-square, and pneumatic circular saw. Good times were had, along with frozen hands.

[tedmich]

+1 with Defaced

I have discovered negative rake carbide circular saw blades for aluminum, they work GREAT. They don't load up with the soft Al and grab dangerously like aggressive positive rake/wood blades. Freud makes an excellent version called Diablo

notice a radius dropped to the blade tips intersects the bottom of the tip before the top.

[Pdavis68]

I used a nibbler recently on aluminum for the IEC jack. Between that and a file, you could do just about any size/shape hole.

Lowell, did you ever say how big a hole you're trying to make? You mentioned something about 1 3/8"-1 3/4" punches. Here's a 1 3/4" Greenlee. I highly recommend Greenlee punches. You can usually get them used on e-bay for a reasonable price. I recommend buying a used one on e-bay instead of buying one new. If you take good care of them, you can use them a number of times and then sell them back on e-bay for what you paid for them. I have a couple I bought on e-bay. I've punched a number of holes and they've shown no signs of wear yet.

[Chuck H]

I highly recommend Greenlee punches

Good product

I recommend buying a used one on e-bay instead of buying one new.

OOooo..!?.. This is a real buyer beware situation. But like anything else, it is possible to educate yourself on what to look for in value. Like 'Is there any room left on this tool for re-sharpening if that's what I'm up against. And do I have the resources to do that?' I only mention it because even a misrepresented item on *bay is usually more hassle than it's worth to recoup your loss if you get reamed. I only mention it because it's happened to me.

If you take good care of them, you can use them a number of times and then sell them back on e-bay for what you paid for them.

Woah!?! That's fine if you plan to represent them honestly. Assuming by this comment that the plan is to unload them rather than re-sharpen them. Otherwise, any intention, not that it was expressly implied, to unload a "used up" tool that cannot be refurbished or isn't represented as needing that on an unsuspecting buyer is just bad form and reinforces my warning about buying used on *bay. Perhaps the OP should just make sure not to buy from you

I have a couple I bought on e-bay. I've punched a number of holes and they've shown no signs of wear yet.

This should always be the case WRT aluminum chassis. Tool steel is MUCH harder than aluminum. In a factory that makes sheet aluminum parts a tool steel punch would be expected to last for many hundreds, or even over a thousand holes. It would then likely be re-sharpened and expected to do it again! Some modern punches and dies are only surface hardened and don't resharpen well. This is something to watch out for. Then there's the precision alignment of the tools in that case that can't be recreated on a bench. But a good tool steel punch, like the Greenlee, and even used (but in good condition) should easily recover it's cost working aluminum even by hand.