The Long Taper

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spro
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The Long Taper

Post by spro » Sat Dec 08, 2018 2:42 am

Long taper noses are self locking. They are like a Brown&Sharpe in reverse. Variations of the angle require clamping methods to hold a chuck, as in the "L" series and they require a substantial key and clamping collar. Hardinge and others, used a taper spindle with a Tee slot. The mating surfaces were so true between the spindle and plate, a mere pin held it tight. It was about the taper drive.
Going backward , a Hendey universal mill has a threaded spindle. The spindle drives #10 Brown&Sharpe arbors but a chuck can be fitted. Attachments can be fitted to the screw nose. Later on, Brown&Sharpe #2 universal with single overarm, has a tapered nose. It may be the only one I've seen but it made sense at the time. There are no key ways or blocks to hold a more acute angled holder. You had the #10 inside but consider that the bore was rather large. A holding "tube" fit thru to maintain tension for the taper.
EDIT: No it wasn't a tube.
Last edited by spro on Sat Dec 08, 2018 4:54 am, edited 1 time in total.

spro
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Re: The Long Taper

Post by spro » Sat Dec 08, 2018 4:40 am

This goes back to taper as the Ames semi universal had. Narrow tapered nose then bigger tapered nose, then gone. I have to think about this. Maybe not. The smaller nose uses 3AM collets the larger uses 1AM collets. Looking side by side, I see the B.C. Ames has almost identical swing as my Asian counterpart. There were differences between the older and newer Ames heads bolts and verniers on the other side but that doesn't matter now. It is about the nose and collets. Stock could be passed thru either with a mounted chuck but the Ames uses a hollow tube for collets. The diameter of the spindle is actually wider at the back than the counterpart. That was for the tube and allowing longer stock to pass through. MT and B&S are blind by central drawbar.

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tornitore45
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Re: The Long Taper

Post by tornitore45 » Sat Dec 08, 2018 11:10 am

It is my experiences that long taper will not keep under radial forces without a drawbar. Any machine that must pass stock trough a chuck can't really use a taper drive.
Mauro Gaetano
in Austin TX

John Hasler
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Re: The Long Taper

Post by John Hasler » Sat Dec 08, 2018 12:26 pm

tornitore45 wrote:
Sat Dec 08, 2018 11:10 am
It is my experiences that long taper will not keep under radial forces without a drawbar. Any machine that must pass stock trough a chuck can't really use a taper drive.
It could with a tubular drawbar. I know of no machine that uses one, though.

spro
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Re: The Long Taper

Post by spro » Sat Dec 08, 2018 6:01 pm

This gets back to a question and I have seen the answer. There are plates and chucks with a hollow extension out the back. They also have a collar which isn't understood to be a taper which fit the nose. I bought my B.C. Ames right here from valued member and contributor to this site.
There was an unwritten understanding that it wouldn't be modified. The base has a propriety shape to fit B.C. Ames lathes or mills of a certain model. No way that I will screw that up.

spro
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Re: The Long Taper

Post by spro » Sat Dec 08, 2018 8:56 pm

So the retention on the outer tapered nose was the same collet tube. Pulling the plate tight over the nose is very tight fit. I'll bet many of those tubes are lost to history because the machinists banged on them to release the chuck. Somewhere it said to grab round stock in the chuck, rap in on that.

John Hasler
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Re: The Long Taper

Post by John Hasler » Sat Dec 08, 2018 10:55 pm

They needed to make the drawtube captive on the back end of the spindle so the unscrewing it would drive the chuck off the taper.

spro
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Re: The Long Taper

Post by spro » Tue Dec 11, 2018 2:55 pm

That is true and there is method for that. Must note that the collets were somewhere around C 3 1/2 , Meaning they were not self locking and the drawtube was held to eject them. What I'm getting to is the outside tapered nose. That is a lock which required more than the fine threaded tube to release a chuck but it surely needed tension in operation.
I just think it is novel the ways it worked compared to our Asian counterpart
Open collets up to 5/8" using drawtube // B&S B-0 closed using MT or B&S collets and draw bar
Chuck draw bar tight either direction // B&S B-0 threaded nose, one direction, open spindle
The Ames doesn't have a simple indexing plate behind the nose so a two ring affair of one thread inside the other ring.. Two hook spanners would eject the chuck while bearing directly upon the bearing plate.

spro
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Re: The Long Taper

Post by spro » Sat Dec 15, 2018 2:41 am

This is a correction to my first post of this subject. The Brown & Sharpe #2 universal, single ram did have secondary key drive at the tapered nose. . It is opposite the way used now or used to be.

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