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View Full Version : Squaring Small Work in a Three Jaw Vid



aboard_epsilon
12-20-2008, 07:08 PM
Got to be making myself, one of these .


http://uk.youtube.com/watch?v=tn7A9PqNftY

Now before you lot start ........don't go on about him running dial indicator against spinning work.........apart from that i think it's a good vid

all the best.markJ

HSS
12-20-2008, 07:21 PM
Think I'll add one of those to my tool box, too.

Pat

oldtiffie
12-20-2008, 07:32 PM
That's a "goodie" Mark.

But a couple of cautions with regard to the "shaft" in particular.

The part was only true where the bearing had been. ie if it was "out" at the chuck it would have been "out" at the tail-stock end as well. Further, he was not gripping much of that flange and "true-ing up" was causing the part to "walk/creep" in the chuck jaws. Note too that a little "pushing" from the bearing was making the job move quite easily. I would be VERY wary of cutting anywhere, especially near(er) the tail-stock end, without support from a tail-stock centre ("live" or "dead").

John Stevenson
12-20-2008, 07:54 PM
Yup old trick,
What he should have done was to run the dial gauge and the roller at the same time and he'd have got a lot better.
No need to run under power, about 5 or 6 revs by hand would ahve got you there and less hassle.

The best way though would have been soft jaws, less pucker factor, not having to indicate every piece and stop bell mouthing a set of jaws that may be hard to replace.

One use he didn't show is to spin a thin welded disk true like what you get when you make things like conveyor rollers, weld two disks to a shaft, spin them true and pop a tube over and weld that.

There is a big one with about a 2" bearing on somewhere in the crap on the tray of the big TOS just for this purpose.

.

motorworks
12-20-2008, 08:31 PM
Nice Idea!

Been doing something similar for years:

Run the work slow by power or by hand.
Take a piece of "heavy" bronze or brass and tap
the work true.
You can usually get it to a 0.002 or .003 then break out the
clock if needed.
eddie

Alguy
12-20-2008, 09:08 PM
I have one and never knew what it was for, it is 3/8 round shaft with 5/8 od bearing mounted on the end of the shaft. Mine must have been put in the tool holder. It was in the box of tooling that came with the lathe. I asumed it for a specific job. In the past i have used a piece of key stock to center stuff by rubbing agianst the part I figured it was not the right way to do stuff so i rarely did it. good tip and thanks

barts
12-20-2008, 09:42 PM
Nice... one could slot the end of some 3/4" CRS for the bearing and use a boring bar holder if one wanted to avoid opening the doors to do some welding .... Inline skate replacement bearings are available at mall-type hours and prices....

hornluv
12-21-2008, 12:24 AM
I like the way he made the tool using pins welded on to fit on the tool holder. I cringed when he left the chuck key in there and turned around to go grab something else though.

IdahoJim
12-21-2008, 12:36 PM
I like the way he made the tool using pins welded on to fit on the tool holder. I cringed when he left the chuck key in there and turned around to go grab something else though.

I agree...great way to make toolholders if you don't have a mill. I was hoping he wouldn't fire-up the lathe with the chuck key in there!
Jim

Teenage_Machinist
12-21-2008, 01:13 PM
Chuck Key: I have been hit in the nuts by a chuck key once.

It's just like a wiggler in the mill, except for the wiggler is the work


"in old Soviet Russia, the wiggler indicates YOU!"

mochinist
12-21-2008, 01:21 PM
"in old Soviet Russia, the wiggler indicates YOU!"lmao




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