4 Jaw Chuck And Steel Plate

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.
 
OK, at 16ga I take back what I said above. Think flying knife blade:eek:. 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.:)
 
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 :)
 
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
 
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
 
Nice work Aaron, looking forward to seeing more of your projects.
 
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