Cutting Aluminum Sheets

[barkster]

I've built a cnc router with wooden frames and now I'm ready to step up to an aluminum frame machine. What is the best way to cut sheets of aluminum say 3/8" or something. I've cut aluminum sheets on my table saw but never that thick. My harbor freight band saw seems like it would take forever. What is the best way to cut my sheets. Thanks

[ger21]

If they are square, the table saw is the way to go. For curved pieces, make a template on your cnc out of wood, rough cut with a jigsaw to within 1/16", then use a pattern bit in a router with the template to finish the edges.

Gerry

[barkster]

What type of blades would your recommend for the table saw and jig saw. I didn't think the jig would cut that thick. I used a carbide blade on it to cut some 1/8" and boy were those chips hot and flying everywhere. I couldn't cut 3/8" in one pass on the table saw could I? Thanks

[HomeCNC]

It is best to cut in one pass on the table saw. Use a carbide blade and raise the blade as high as it will go, this will make the cutting angle almost in the vertical plane. I have cut 3/4" with no problems. Just move SLOW and protect your eyes and arms.

[barkster]

Thanks I'll get me a good blade and try it.

[ger21]

60 to 80 tooth triple chip grind (TCG). Wear glasses like Jeff said and cover your arms if possible. (hot chips) But with a sharp blade, it actually cuts pretty easy.

Gerry

[barkster]

Yeah, that's what I remember from cutting the 1/8" HOT!!! & Messy. That's why I thought the 3/8 might be a bit much but sounds like it will cut ok. Thanks guys.

[Hobbiest]

For the jigsaw blades, get a low TPI. According to the machinist manuals that I have read, tooth count should relate to thickness of the material being cut, ie. a .250 wall tube should have a 16TPI blade, thicker material should be arranged so that at least three teeth contact the material at any given time. Same goes for hacksaw and bandsaw blades too. A little beeswax on the blade will help to keep it from loading up with aly chips too.

[Mr.Chips]

There right. I use a full face shield, long sleeves, the metal is HOT and it gets everywhere.

I hane cut 1/2" in one pass.

Hold the material really tightly, stand firmly and don't change your footing when cutting. If you jam the alum/blade the kick back safety feature won't work because the alum is too hard for it to bite into.

It's a good idea to have another person there to shut off the say if the blade becomes stuck, because you need BOTH hands firmly on that potential projectol.

With care and precautions you can cut it safely, and the finish isn't too bad either.

Hager

[ballendo]

Hello,

I cut aluminum daily on a table saw. Mostly 3/8, 1/2 and 5/8 wrought and cast tooling plate...

Definitely consider getting an aluminum blade, as the zero rake angle makes everything MUCH safer. At a minimum, use the TCG (Triple Chip Grind), though I useta use an atbr.

FWIW, it REALLY heps to use some lubrication. i've used sprays, both on the blade, and on the cutline, and they work and are less messy than what I'll next describe. Homedepot sells a spray lube that I've had reasonable success with.

But the best is to use the beeswax lube stick available at machine shop supply houses. You can also use a BEESWAX (be sure it's not some modern synthetic, as they're becoming more common!) toilet bowl seat ring.

I rub this against the spinning blade--both sides-- before cutting. And I "draw a line" of beeswax down my cut path, so the blade pulls it into the cut. It makes a HUGE difference in cut quality, and ease of feeding.

Safety is a BIG issue when you do this, so heed the advice to protect your eyes, hands and arms. On a day that I 've cut a lot of parts this way, my arms look like I have measles from the tiny cuts made by flying shrapnel (Because using long sleeves, which would prevent the cuts, leads to another safety problem, that of catching a sleeve. Since I'd rather have many tiny scratches instead of one huge cut, I put up with the flying bits.)

Should say here that I'm a lifetime table saw user, and have not had the plastic guard on in years. I'm sure it would help immensely. For me it presents other problems, but I'd be remiss in suggesting you follow my lead and not use it.
anyway, be sure you have "tuned up" your saw before cutting aluminum. You want the bearings and belt(s) tight, and the miter gauge and rip fence settings exact. No 1/16 bigger at the outfeed end!

And I'll make one observation in disagreement with what others have said. Although I often do cut full depth in one pass, I have had great results in taking several cuts. If you flip the part it will take only a few passes to go through, even with a lower grade table saw. Mine are heavy duty industrial types. With the multiple cuts, you can get the beeswax into the groove of the prior cut...

Also, consider using a two-step sizing operation. Get the piece cut though using multiple passes, but a BIT oversize. Then "true it up" to size with a full depth cut, taking less than 1/16 from an edge. You'll be safer, and have great results!

Hope this helps,

Ballendo

[ger21]

A sliding crodsscut sled will make things safer and easier as well.

Gerry

[barkster]

Thanks, I went to Lowe's to see if they had a blade that I could use but of course I couldn't find any that stated anything about TCG (Triple Chip Grind), what is that is that? I just bought the nicest titanium carbide blade I could get 60 tooth. Were do I need to go to get a good blade for aluminum on the net or where ever like ballendo suggests? What is atbr?

Thanks