cutting metal plate on a table saw?

Jim R. · 5335

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Offline Jim R.

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on: August 07, 2013, 09:50:10 AM
I want to get started on my amp projects and I currently don't have the money or space for a decent bandsaw so I'm wondering how well it may work to cut some metal plates down to size on my table saw?  We're talking copper up to 0.125" and aluminum maybe up to 0.250 and it's a 10 inch saw with a 4.5 hp motor.  I vaguely recall doing this with an abraisive cutoff disc in the past, or watching somebody do it, but it has been a while.

Can anybody recommend a good 8" or 10" blade that can do this and any other helpful hints (except for wearing good heavy gloves to avoid geting burned by hot metal?)

First order of business is to cut a 12" x 24" x 0.125" copper sheet into 2 10" x 12" pieces as these will be the plates for my rebuilt SR-45s.

Thanks,

Jim

Jim Rebman -- recovering audiophile

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4krow

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Reply #1 on: August 07, 2013, 10:09:18 AM
  In my experience, cutting metal on a table is not so much about the power, but about feed rate, and number of carbide teeth on the blade. I wouldn't try it with less than 60 teeth, and keep the feed rate slower than usual. I'm not sure about blade height, since there are different opinions about it, but you might want the blade to just clear the plate that it is cutting. Often overlooked is the rip fence, where as the metal plate might slide under it.



Offline Jim R.

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Reply #2 on: August 07, 2013, 10:15:10 AM
Greg,

Thanks, but I'm not about to be cutting any metal with my Forest blades :-).  I'm thinking more about a carbide abrasive disc -- at least that's what I believe I saw it done with in the past.  Though maybe a cheap harbor freight high tooth count carbide blade will also work.  I thought about the fence too, but on this saw it is nice and tight to the cutting surface. but also has screw holes so one could mount a piece of hardwood to it if you wanted.

Thanks,

Jim

Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline Mike B

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Reply #3 on: August 07, 2013, 10:23:08 AM
I have cut lots of aluminum plate up to 1/4 inch on my cheap $100 table saw with carbide tipped blade.  Push slow.

Not a problem except for the hot chips coming out the holes in the bottom.

Don't wear shorts.

Far away from the bleeding edge


Offline adamct

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Reply #4 on: August 07, 2013, 10:54:04 AM
Or flip flops!



4krow

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Reply #5 on: August 07, 2013, 11:05:13 AM
I wouldn't use my Forrest blades either! HA! But since it is copper, a non-ferrous metal, and is thin, a carbide blade would have no trouble with it. The abrasive disc on the other hand, may be relatively thick, and produce more heat as well as a build up in the grit of the disc. Again, being thin, you probably don't have that much to worry about(I mean the metal,  guy). HA!



Offline rif

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Reply #6 on: August 07, 2013, 11:41:38 AM
Any reason not to use a jig saw? I don't know much about metal.

-david


Offline 2wo

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Reply #7 on: August 07, 2013, 12:02:08 PM
For Al and Cu, don't try an abrasive disk. they will load up. For a few cuts a cheep fine tooth plywood blade will work fine if you go slow...John

John S.


Offline howardnair

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Reply #8 on: August 07, 2013, 12:11:33 PM
no problem-i do it all the time with copper and aluminum-i use my compound miter saw with a high quality 80 tooth freud blade-just make a couple passes --won't affect the carbide tips at all-



Offline howardnair

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Reply #9 on: August 07, 2013, 12:13:56 PM
no problem-i do it all the time with copper and aluminum-i use my compound miter saw with a high quality 80 tooth freud blade-just make a couple passes --won't affect the carbide tips at all-



Offline Jim R.

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Reply #10 on: August 07, 2013, 12:35:11 PM
Ok guys, I'm convinced so I'll go and order an appropriate blade and get this done.

BTW, I use the 4" harbor freight blades on my dremel mini table saw and they are great.

You guys are great!

-- Jim

Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline Paul Birkeland

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Reply #11 on: August 08, 2013, 06:38:17 AM
I've seen all those materials cut on a panel saw with a 10" blade at reasonably high feed rates (though I was informed that the blade in question was $150). 

Paul "PB" Birkeland

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Offline RPMac

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Reply #12 on: August 09, 2013, 03:29:22 AM
Jim, I have a question. Why not 12X12? You can always fill up the extra space with bigger caps.

A sheet metal shop or votech school with a sheer could make quick work of this.



Offline Jim R.

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Reply #13 on: August 09, 2013, 04:36:55 AM
Hi Robert,

Couple of reasons -- first is that the large copper plate has a hole in it a few inches in from one end, second is that my amp stands are 12" x 15" as the amps will sit between the rack and speakers on the floor.

As for the sheet metal shop, it's hard for me to get around as my wife needs to work and she's occupied with that most of the working day, plus a lot of such chops around here don't want to do small jobs.  I have to drive 45 minutes out of town to the powdercoater, but he will do small jobs and he does great work, but I only do that once or twice a year.  I wish I had a shear and brake of my own, but one beefy enough to handle 1/8" copper would be quite expensive and far too large for my limited shop space.

Usually I just buy the pieces cut to size from onlinemetals.com, so it's really only this big piece of copper that I need to deal with.

Good suggestions though.

-- Jim

Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline najo49

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Reply #14 on: August 14, 2013, 06:25:38 AM
I have been a professional woodworker for years. A carbide blade that is sharp will do a fine job. do not have the blade high just above the material you cutting. good luck. Jan Olsen

Jann Olsen, [email protected].  Lowther medallion 2 with pm2a./ extended foreplay lll,/EROS phono /Grado ref/ SOTA star Vacuum SME V, /  45 amp direct coupled,c4s,mQ nickel  / paramour  2a3 w MQ iron /Original SEX monos /Jena Cables /heathkit wm6a/ proAc Tablette 50 sig , with push pull