Need help cutting aluminum sheet -- design project

[geologist]

So back in college, I splurged on a MacBook -- the one with the white polycarbonate shell. My experience with CRAPple Care (2 x repairs, and one time it came back with a dead battery that Apple refused to replace -- looking like it had been thrown across a room) leaves a bad taste in my mouth. From a computer standpoint, even being as old as it is (purchased in 2006), it still runs circles around my NEW laptop. However, the MacBook had a major design flaw that caused the palm rest to chip away:

I recently dug my old MacBook out, and decided to polish the plastics, clean up the palm rests, and put a new battery on it. It's about to spend the rest of it's life as a shop computer.

With that said, I was thinking about how I could keep this problem from getting worse. After thinking about it for a bit, I decided that *maybe* I could get some 3/32 aluminum sheet and fashion a set of palm rest covers, which would then be polished and permanently affixed to the existing palm rests with epoxy.

I can lay the design out with no problem, but trying to cut these out with shears is leaving the edges dangerously sharp. Do any of you have a CNC plasma table or method of cutting these out that will yield softer edges?

 

[racingtadpole]

Woodwork router

 

[Kevin54]

Give me a drawing and I can fix you up.

 

[theoldwizard1]

A metal shear (a.k.a. "jump shear") is your best tool. Hand held power shears would work also. I'm not certain how well a nibbler would work.

Some people have had good luck using a circular saw or table saw to cut aluminum with a non-ferrous blade.

 

[MoonRise]

It's just aluminum sheet.

Cut out your pieces and then file/sand the edges to the desired smoothness. Done.

Note that 'raw' aluminum will usually leave black oxide marks on your skin as you rub up against it. Anodize it to 'seal' the aluminum and prevent such skin marks.

 

[Rex Stallion]

Table Saw works like a champ with a Carbide blade.

 

[rdn2blazer]

A metal shear (a.k.a. "jump shear") is your best tool. Hand held power shears would work also. I'm not certain how well a nibbler would work.

Some people have had good luck using a circular saw or table saw to cut aluminum with a non-ferrous blade.

lol, funny, never heard "jump shear". Stomp shear yes but not jump shear. Intresting. On a budget buy some power shears like KET or others out there.

http://www.northerntool.com/shop/tools/category_power-tools+cutting-shears

 

[MP&C]

1. Go to your local box store and buy a 24 x 24 piece of said aluminum
2. Go to your local HF store with metal "sample" to test how well their stomp/foot/jump shears operate.
3. Go home and file the sharp edges.

 

[willy3486]

I work on these things for a living. You think that is bad design wait until you have to have one of the new ones worked on. The ipads,new imacs Ipods all have that glass front held on by 2 sided tape. The preveous models used magnets to hold the glass in place and was a slick way of doing it.

As far as this model I am very familiar with it. I have a lot that does that. Due to cost of replacing them all I was left to taking off any burrs and then sanding them smooth. Most of the time someone puts clear tape over that area.,we have a small budget. If you want to just replace the keyboard let me know. I can put you in touch with a few companies you can order from. The replacement keyboards seem to have this issue fixed. If you need to know the part number let me know the serial number and I can look it up, that is if apple hasn't taken it off the cross reference guide. Its probably part number 922-5590 . As far as replacing it is fairly easy. If you do have a ice tray handy. Take the 3 screws in the bottom and put them in a cube area, then the 4 screws in the back into the next cube area,etc. They have different screws in each area. If you have questions PM me.

 

[theoldwizard1]

lol, funny, never heard "jump shear". Stomp shear yes but not jump shear.

Skinny guys (not me) !

 

[geologist]

Give me a drawing and I can fix you up.

I'll get you a drawing by tomorrow afternoon. I can't stop sneezing because of my freaking allergies tonight.

I work on these things for a living. You think that is bad design wait until you have to have one of the new ones worked on. The ipads,new imacs Ipods all have that glass front held on by 2 sided tape. The preveous models used magnets to hold the glass in place and was a slick way of doing it.

I've had it replace three times by Apple. Once in store, once sent to Tennessee, then after it looked like it had been thrown across the room, again via the stores. I'm still pissed about the battery. Doesn't make sense to order another top case, just to have it happen again after a few thermal cycles. It's the white MacBook (late 2006). The way I look at it... $10 for aluminum and epoxy = done forever. I don't sell my old computers, so I'm not worried about resale. This MacBook replaced my Titanium PowerBook, and my lime iBook Clamshell before that. I'd consider a MacBook Pro or MacBook Air in the future, provided drop-off and pick-up occur at a store, where there's no he-said she-said horseshit like the last time around.

 

[BFBOB]

General principle: You can work aluminum with all power woodworking tools at woodworking speeds. No need for speed reduction as when cutting steel. The edges will often need some file work (or sandpaper), but you can use table saws, bandsaws,saber saws, Sawzalls, drills of course, routers, thickness planers. Jointers can be used in theory, but it's a really rough ride, so much so that I don't consider it safe.

One power tool that I've found not to work acceptably is grinders. The grit loads up and creats big lumps on the wheel that beat your workpiece (and your hands!) to death without doing any actual work. If this is a gap in my knowledge (and I hope it is!) and there's a special class of abrasive wheels that work well on aluminum I'd sure appreciate someone cluing me in!

 

[geologist]

General principle: You can work aluminum with all power woodworking tools at woodworking speeds. No need for speed reduction as when cutting steel. The edges will often need some file work (or sandpaper), but you can use table saws, bandsaws,saber saws, Sawzalls, drills of course, routers, thickness planers. Jointers can be used in theory, but it's a really rough ride, so much so that I don't consider it safe.

Do you need a special blade or could I conceivably use the same blades as I do with wood?

 

[Chuck122]

Do you need a special blade or could I conceivably use the same blades as I do with wood?

im pretty sure the carbide woodworking blades are suitable for occasional, light duty aluminum cutting.
also,any angle grinder can be fitted with aluminum cut-off wheels that do not load up like the regular ones (http://www.walter.com/Walter/en-ca/abrasives/cutting-wheels/angle-grinders-aluminum/zip-alu)
in any case, finishing with a file sandpaper or a scotchbrite pad will be necessary if mutilation is to be avoided

 

[BFBOB]

im pretty sure the carbide woodworking blades are suitable for occasional, light duty aluminum cutting.
also,any angle grinder can be fitted with aluminum cut-off wheels that do not load up like the regular ones (http://www.walter.com/Walter/en-ca/abrasives/cutting-wheels/angle-grinders-aluminum/zip-alu)
in any case, finishing with a file sandpaper or a scotchbrite pad will be necessary if mutilation is to be avoided

I use carbide cutters for all my woodworking tools - I expect HSS would work on aluminum as well as it does on wood: pretty well for a while. One thing to bear in mind I should have mentioned is that the aluminum chips fly faster, farther and hit harder than sawdust! Keep covered up.

Thanks for the pointer to AL cutoff wheels - checked it out, video demonstrations and all looks great, but man, do they like them! Next stop, feeBay.

 

[Chuck122]

I use carbide cutters for all my woodworking tools - I expect HSS would work on aluminum as well as it does on wood: pretty well for a while. One thing to bear in mind I should have mentioned is that the aluminum chips fly faster, farther and hit harder than sawdust! Keep covered up.



Thanks for the pointer to AL cutoff wheels - gotta check that out.

What kind of cut quality are you getting out of the woodworking blades? Also, does cutting Al wear them ridiculously fast?
As far as those aluminum cutoff wheels, grinding wheels are also available, made out of the same abrasive. I also use purpose made aluminum carbide burrs(http://www.josco.com.au/newsite/jia/products/carbideburrs/abrasives_bac.htm). Since I usually weld whatever I cut, I'd have to segregate my tooling anyway to avoid contamination so I much rather have specialized tools

 

[BFBOB]

The cut quality on AL is not great - pretty good on the cut face, but it always raises a significant burr. I use a carbide deburring tool followed by a file to smooth it off. Most of the AL work I've done is cutting plate on the table saw when straightness and accuracy of cut is important. If the cut doesn't have to be exact because other shaping will be needed, I prefer the bandsaw. I've also used the router to do circular cuts, which works very well (with the burr problem, though), and done light milling with router bits in my drill press with a cross-slide vise.
The bits and blades don't seem to wear any faster than they do cutting wood, that is, pretty much imperceptibly.

 

[machine_punk]

I cut aluminum sheet all the time with woodworking power tools. HD sells a laminate/non-ferrous blade for a decent price. Or, any triple-chip grind carbide-tipped blade will work.

I get gorgeous cuts with the tables saw. If you want a particular shape, make a wood template and cut the aluminum with a template following router bit.

As far as dulling the sharp edges, I use ScotchBrite in a ROLOC adapter on my air grinder. For the small size of your project, you could easily just use some red ScotchBrite pads and lubricate the aluminum with isopropyl alcohol while smoothing the sharp edges.

Of course, if it is an easy shape, you can cut the shape 'close' with a jig saw, then use a disc sander or file to cut up to the line. Then use the ScotchBrite on the edges.

Lotsa ways to skin this cat.

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Kev

 

[geologist]

If anyone wants the measurements of the palm areas (with nice radiuses on all 4 corners to match the radius on the edge of the MacBook (white, 2006-2008), here it is:

https://scontent-a-lga.**.fbcdn.net/hphotos-xap1/t31.0-8/10669235_783709843190_6539365314026391880_o.jpg

 

[theknurl]

General principle: You can work aluminum with all power woodworking tools at woodworking speeds. No need for speed reduction as when cutting steel. The edges will often need some file work (or sandpaper), but you can use table saws, bandsaws,saber saws, Sawzalls, drills of course, routers, thickness planers. Jointers can be used in theory, but it's a really rough ride, so much so that I don't consider it safe.

One power tool that I've found not to work acceptably is grinders. The grit loads up and creats big lumps on the wheel that beat your workpiece (and your hands!) to death without doing any actual work. If this is a gap in my knowledge (and I hope it is!) and there's a special class of abrasive wheels that work well on aluminum I'd sure appreciate someone cluing me in!

with saw blades you need to watch the 'hook' angle of the blade, like in post #18

there aren't any abrasive stones worth trying on aluminum.....

get a 6 flute carbide aluminum burr, I prefer the rounded tree and olive shapes for porting heads and weld prep... cylinders and long points don't get used

use a lube.....machinist's wax works the best, you can use WD-40, but then the chips stick EVERYWHERE

I have burrs I've used for 30 years without sharpening

good quality burrs LAST, the cheap stuff doesn't

 

[Alchymist]

I cut thicker aluminum with a jig saw and metal cutting blade. Thin stuff can be sandwiched between two pieces of plywood to cut. As to sanding/filing, I use flap disks in a 4-1/2" grinder similar to these:
http://www.lehighvalleyabrasives.co...s/Categories?gclid=CLXZtL-j1cACFQaCMgodHVoAZA

 

[theultimatehic]

lol, funny, never heard "jump shear". Stomp shear yes but not jump shear. Intresting. On a budget buy some power shears like KET or others out there.

http://www.northerntool.com/shop/tools/category_power-tools+cutting-shears

That's funny... I always refer to it as a "jump shear" but never heard t called a "stomp shear". Guess we are opposites there. As far as easiest way to make edges smooth, just file them after you cut. Off you already have a circular saw that will work too just get the right blade for it. I'd just file it If you don't wanna spend the extra money. It won't take long to do at all either.