Drill Chucks

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liveaboard
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Re: Drill Chucks

Post by liveaboard » Thu Jan 11, 2018 6:40 pm

On advice given here, I bought an MT2 reamer to dress the bore, and that helped; but still, things have to be correct or the bits pop out of my antique drill press.
Some of the problem is my poor bit grinding skills, some the strange things I try to drill, like misshaped holes and things.
My single point boring tool is often aggravating, popping out of the taper. But even that will work ok if the grind on the cutting bit is good, and the side pressure reasonable. That tool makes vital cuts that I have no other way of boring. Like making round 30mm holes in egg shaped hydraulic cylinder ends.

My wife asked what I'm writing about; "Boring!" I told her.
"Just as I suspected." she grumbled.

John Hasler
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Re: Drill Chucks

Post by John Hasler » Thu Jan 11, 2018 7:05 pm

I wouldn't expect a Morse taper to hold a boring tool without a drawbar.

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Re: Drill Chucks

Post by liveaboard » Fri Jan 12, 2018 1:30 pm

Exactly!
I have a bushing set into the table, and it works ok when it's well centered [obviously, there has to be a through hole for the tool shaft].

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Re: Drill Chucks

Post by John Hasler » Fri Jan 12, 2018 1:37 pm

So you are essentially line boring? Could you explain in more detail? Sounds interesting and useful.

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Re: Drill Chucks

Post by liveaboard » Fri Jan 12, 2018 5:19 pm

I dug up this picture; I'm boring the end of the hydraulic steering cylinder from my tractor for a new spherical joint.

The boring tool just a piece of 25mm rod with an MT2 taper at one end and a slot for the cutter about a third of the way from the bottom. There's a hole through the rod to the bottom, threaded for an 8mm clamping screw.
I made 2 bushing holders that fit into the center of the drill press table, one that sits flush and the other raised about 30mm [pictured].

A difficulty is that the tool needs to be raised high enough to slide the work under it for clamping, and then have enough travel to get deep enough to finish the job.
That's because the table has to be accurately aligned with the tool and then clamped in position before the work piece is clamped to the table.
My table will not lift without also being free to swing out of line.
steering cylinder bore.jpg
edit; found a couple more pictures from when it was new and shiny.
boring tool 1.jpg
Boring tool 2.jpg

John Hasler
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Re: Drill Chucks

Post by John Hasler » Fri Jan 12, 2018 10:02 pm

Clever!

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liveaboard
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Re: Drill Chucks

Post by liveaboard » Sat Jan 13, 2018 1:10 pm

Necessity is the mother of invention!
And the tool came with my favorite price on it.

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warmstrong1955
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Re: Drill Chucks

Post by warmstrong1955 » Sat Jan 13, 2018 1:24 pm

Nice work, and gettin' her done with what you have!

I looked for pics, but I have none, on a very similar set up I did repairing some cylinder mount clevises on a drill jumbo. There wasn't room for our York portable boring machine, without taking the whole boom apart.
I had a short piece of a portable boring bar, a leftover from another job. I turned one end down to fit the Milwaukee mag drill, and made a bushing & boss for the opposite end to stabilize the bar. I welded up the bores, then welded on a plate to locate the mag drill, and welded on the bushing holder on the opposite side, and bored away.
Saved a whole lot of time.

Bill
Today's solutions are tomorrow's problems.

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Re: Drill Chucks

Post by liveaboard » Sat Jan 13, 2018 6:47 pm

I'll have to share my home brewed solution for boring the clevises on my tractor's front end loader pivots; the 2 pairs of holes are 4 feet apart and have to be in line.

The boring tool for the drill press makes nice straight round holes, but getting a precise diameter is very difficult.
When I'm going to fit a part I make myself it's no problem, I just turn the part to fit the bore. But getting a fit for a bearing is so tough, I usually cut oversize and then make a sleeve on the lathe.

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