Drilling to Get Rid of Excess Metal?

SteveHGraham · Post by **SteveHGraham** » Thu Oct 08, 2009 9:07 am

I've read that a drill is a good tool for moving metal in a hurry. I'm wondering if I should use one on something I'm making.

I took a square piece of aluminum and tried to turn it into a round pulley. I took the corners off using an end mill and a rotary table on the mill. But I screwed up the axle hole, so now I'm going to give it another shot.

Removing the corners took forever. Would I be better off using a 1/2" drill, going down into the corners parallel to the axle?

I ordered some boring tools so I won't mess up the hole again.

Rick · Post by **Rick** » Thu Oct 08, 2009 9:39 am

Steve

The easiest way is to saw off the excess. But if you lack a band saw I would put your piece in the mill vise on edge at 45 and mill the corners off that way. This takes 4 set ups but they are not precision setups and the milling will go faster. Then you could do the finish passes on your rotary table. A old toolmaker I know from Hungary told me one time that if I take more than one rough cut and two finish cuts then I am wasting my time and his money. That has stuck with me and though it is not always true in most cases it is a pretty good method to go by. Now by a rough cut can be a saw cut, you just have to saw close enough so you don't have any excess stock. On account of this guy I learned how to operate a band saw very well.

Rick

SteveHGraham · Post by **SteveHGraham** » Thu Oct 08, 2009 12:03 pm

I can't use a band saw on vertical 3 1/2" square stock. It's not long enough to clamp in the saw without running the blade into the cast iron.

Rick · Post by **Rick** » Thu Oct 08, 2009 12:11 pm

I believe you are refering to a horizontal band saw, I was refering to a vertical. If you are refering to a vertical then I don't understand.

Rick

SteveHGraham · Post by **SteveHGraham** » Thu Oct 08, 2009 12:26 pm

I have two band saws. A vertical saw for wood, and a Northern Tool 4 x 6 horizontal for metal. The horizontal can be used in a vertical position, but I haven't tried it.

Frank Ford · Post by **Frank Ford** » Thu Oct 08, 2009 1:19 pm

Don't forget that you can cut aluminum on your vertical wood band saw - the cutting speed for aluminum is the same as for wood. Before or during each cut, touch an old candle to the blade. This simple application of paraffin lubrication will prevent clogged teeth - simple as that:

SteveHGraham · Post by **SteveHGraham** » Thu Oct 08, 2009 2:47 pm

Won't the swarf ruin the tires? Great post, regardless.

Frank Ford · Post by **Frank Ford** » Thu Oct 08, 2009 3:29 pm

Swarf doesn't ruin tires. I have two Delta 14" band saws, both of which have original rubber tires. The wood saw I bought new in 1971, and it's had a lot of use in hardwood and aluminum all that time.

The other saw is the 1943 metal cutting version, and I've had it since about 1976.

The only time I had a tire problem was many years ago when I had a minor lapse of judgment and used the wood saw to cut sections of a big two-foot wide roll of masking tape. What a freakin' mess. That stuff was soooo sticky! Took about a quart of naphtha to clean up the saw and tires. The tape cut rather well, though, because I had it securely clamped to a carrier board.

SteveHGraham · Post by **SteveHGraham** » Thu Oct 08, 2009 3:34 pm

Maybe this is the way to go, then. I can rig something up to hold the aluminum. I'm a little worried about the height. It will have to be at least 4" tall in order to manageable on the lathe.

kvom · Post by **kvom** » Thu Oct 08, 2009 7:46 pm

I would just round it off on the lathe. You infeed from the corners to a round state is .72", so with a hefty lathe it is only a few passes.

Jay, Idaho · Post by **Jay, Idaho** » Fri Oct 09, 2009 8:43 am

Your original idea of drilling holes is probably not a bad idea. I have "chain-drilled" a plate to make a rough disc when we did not have a saw that was suitable. You drill a series of holes outside of the finish part diameter, holes almost touch each other but not quite.
You can then easily saw through the thin webs between the holes and you have something that looks like a worn out sprocket.
Maybe not really efficient but works when you have to get'er done.

larry_g · Post by **larry_g** » Fri Oct 09, 2009 9:58 am

SteveHGraham wrote: I took a square piece of aluminum and tried to turn it into a round pulley. I took the corners off using an end mill and a rotary table on the mill. But I screwed up the axle hole, so now I'm going to give it another shot.

Steve
Is it possible to recover your error on the first pulley. It's not unheard of to pulg a hole in Al and redo. Bore the hole even bigger and make a sleeve to bush it back to proper size. Fixin' bores is perty normal repair work.
lg
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Drilling to Get Rid of Excess Metal?

Drilling to Get Rid of Excess Metal?

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