# 4 Jaw Chuck And Steel Plate



## abrace (Aug 15, 2016)

All,

          I need to bore some holes in a steel plate. I don't have a mill. I only have a G4003G. I can fit the plate in my 4 jaw chuck, but with only TWO jaws grabbing the plate (it is a rectangle) and be able to bore the holes where I need to. It seems to spin up fine and is in there pretty solid. Am I risking my safety doing this or is this a standard thing to do? I am new to using a lathe.

---Aaron


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## JimDawson (Aug 15, 2016)

If the setup is solid you should be OK.  Don't get in a hurry and watch what is going on, be ready to hit STOP.  Just keep your nose back away from the spinny things.


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## savarin (Aug 15, 2016)

Will it fit between the jaws diagonally?
I do that quite often to get a large chunk faced.


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## abrace (Aug 15, 2016)

savarin said:


> Will it fit between the jaws diagonally?
> I do that quite often to get a large chunk faced.


Honestly, I am not sure. I have enough problems figuring out what I want to do with the lathe without diagonal lines getting involved 

The problem is that I need to bore a hole near the top, and to do that I need the top at the center of the chuck, obviously, which makes the bottom hang down below where the jaws even come close to grabbing it.

It has a great hold from the side. Great until I start boring that is and putting pressure on it, but I won't know until I try. I won't have a chance to do this until this weekend, but I did confirm the plate fits and seems to be held reasonably well from the 2 jaws on the side. I spun it up, and it seems OK, but I didn't put any tools to it at all.

I was figuring I would run on the lowest speed, 70RPM.

Yes, I did tell my wife I need a mill. She told me to figure out the lathe first then we would talk....at least she agreed to talk about it!


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## RJSakowski (Aug 15, 2016)

Have you got a face plate?  It may be easier to accomplish your task with it.  You stated that you have multiple holes to bore.  If you drill pilot holes first, you can run a bolt through with a nut and washer on the backside.  You can also make up a clamping system using a bar with a bolt through bridging from your workpiece to a block.  My preference is to have at least three clamping points.


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## Tozguy (Aug 16, 2016)

How big a hole? Are location and dimensions critical? Photos would help.

When in doubt don't. Take heed of RJ's post.


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## Charles Spencer (Aug 16, 2016)

It is difficult to answer without knowing the dimensions of the plate and the hole to be drilled.

Another approach might be to secure it to an angle plate on the cross slide and hold the drill in a collet in the head stock.


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## abrace (Aug 16, 2016)

It is 16 gauge steel plate. Dimensions of the plate are about 4" x 6".

Hole that I need to bore is about 2" in diameter. I also need to drill 2 holes in different places about 1/2" in diameter.

The 2" hole will be for a hobbs meter. This will end up being fabricated into a control box for my air compressor. This piece of plate will end up being the door.

---Aaron


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## francist (Aug 16, 2016)

If it's only 16ga sheet steel I wouldn't fuss with the lathe. Hole saw in either drill press or hand drill followed by a half-round file would get you there pretty quick.

-frank


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## abrace (Aug 16, 2016)

You know what they say about having a new hammer and everything looking like a nail.


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## Rudy_R (Aug 16, 2016)

I'm with Francist on this. We do it all the time at work. Sometimes it can be hard to find a hole saw the perfect size, but going undersize and filing or die grinder the rest of the way is gonna be way easier. I think you'll have a piece of plate flying across the room from the lathe if you try that.


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## JimDawson (Aug 16, 2016)

OK, at 16ga I take back what I said above.  Think flying knife blade.  There is no way to chuck on that without it flexing and thus not being held solidly.  I normally think of plate as being >3/16 thick, anything thinner is sheet metal.

It is still possible to do it in the lathe if that is the only power tool you have, although, a drill press or a power drill and a hole saw would be my choice.

Chuck up a piece of 3/4 inch MDF, plywood, or some other backer in the 4-jaw, then solidly attach the work to that.  You can still use the hole saw in the lathe to get it to a rough dimension, then bore to finish size.


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## abrace (Aug 16, 2016)

I like the MDF idea. I may give that a shot.

I shouldn't call steel this small plate. I know the general rule is 1/4" or greater to be 'plate', but even that depends on the person.

What I am working with is really sheet metal.

Maybe i need a bigger chuck


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## epanzella (Aug 17, 2016)

16 ga? Hole saw. Definitely a hole saw.


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## dulltool17 (Aug 17, 2016)

Hole saw!  Best bet for 16 ga.


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## talvare (Aug 18, 2016)

In my opinion, the BEST way is to punch it with a conduit chassis punch (do you know a commercial electrician ? most of them have these punches). Second best approach is on a drill press with a hole saw. Clamp it securely to the DP table on top of a piece of MDF or plywood. I have done hundreds of holes in sheet metal, up to 6" diameter, using both of these methods.

Ted


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## abrace (Aug 21, 2016)

Update: I was able to do it with the lathe and reasonably safely. I had to have a strange combination with the jaws, with some reversed and some not, and I got it to hold real well. I was able to use all 4 jaws to hold the steel. The steel didn't flex much at all except when the bit would break through the hole. However, I was able to get the steel in the 'V' grooves of the jaws so it hold it really well. I ran it between 70 and 200 RPM depending on what I was doing.

The hobbs meter I bought has very tight tolerances. The meter has about 1/16 wide flange all the way around that has to rest on the steel. Too wide and the meter will pull through. Too narrow and it sits on a ridge of plastic.

My concern with hole saws is that the holes end up bigger than you want, or at least it does when I drill them.

I used an 1 3/4 hole saw to drill the rough hole, then my boring bar to get the hole up to size taking small bites @70RPM.

Hole ended up being 2.005 and the meter fits like a dream.

Biggest problem is that I bounced one of the jaws off the edge of the bottom of the carriage. I spun the chuck by hand to check for clearances before I fired it up, but only checked 3/4 of the way around. Of course the one jaw I didn't check was the one that hit . Scraped some paint off the bottom of the carriage. Learned a valuable lesson there.

Thanks for everyone's suggestions.

---Aaron


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## abrace (Aug 21, 2016)

Still needs to be painted, but I fitted it up. Looks nice. Should do the job.

Would have liked a smaller light, but I had this one left over from another project.




---Aaron


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## Tozguy (Aug 22, 2016)

Nice work Aaron, looking forward to seeing more of your projects.


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