Should I cut my arbor to be able to bore deeper?

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Housey210

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How will shortening the morse taper help? The black mar near the chuck will not change! Leave it be. Look at smaller chucks and tapers.
 

Democritus

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I’m not sure I understand what the problem is here. You say that the chuck ejects after only 3.5 cm of travel, but ejection occurs as you’re winding the quill in, not out. If you cut the arbor off it won’t make any difference to the drilling capacity, because the distance the taper is inside the quill is determined by the MT, and the quill will still only advance 5cm.
Cutting the arbor will only make ejection of the chuck more difficult. I have two jacob’s chucks, one with a short arbor, and the other with an arbor like yours. To get the short arbored chuck out, I have to use a knocking bar through the tailstock.
 

Inspector

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His self ejecting tailstock has to be out 3.5cm in order to seat the MT. If the MT is shorter the tailstock ram can be in further before the self ejecting bit hits the MT, therefore longer ram travel.

Pete
 

chaoticbob

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His self ejecting tailstock has to be out 3.5cm in order to seat the MT. If the MT is shorter the tailstock ram can be in further before the self ejecting bit hits the MT, therefore longer ram travel.

Pete
Well yes, but it's 1.5cm out I think - the OP says the tailstock travel is max 5cm, but he can only use 3.5cm because of self ejection due to the tang. Nothing wrong with grinding the tang (and even part of the taper) off in this scenario. If you go too far just glue shims (washers, whatevever) to the back end of the taper until it ejects when you want it to. That's what I've done in a similar situation.
Bob.
 

Robbo3

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Morse Taper Adaptors.jpg


1 APTC live centre
2 APTC 4 prong drive centre
3 Hollow multihead live centre
4 APTC live centre (supplied with lathe)
5 Serrated drive (Steb type)
6 3/4"x16 adaptor
7 2MT to 1MT adaptor
8 Finial support live centre
9 MT2 to MT2 alignment adaptor

Note how the length varies.
Items 1,2 & 4 came with the Axminster lathe.
Item 1 has had the shank shortened
No 3 ejects with 10mm before it should.
 

ChaiLatte

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...The purpose of the flat is to engage in a slot on some morse taper to prevent the arbour from rotating when drilling...

Please, that is not correct. The Morse taper relies on the friction of the taper to transmit the driving force, not any contact between tang and slot.

If a person is in a situation where drive does get transmitted via the tang, that is not a normal mode of operation and either the male taper or the female taper or both are unservicable.
 

Sandyn

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Everything you wanted to know about Morse tapers, but were afraid to ask:-This shows the dimensions of different tapers. I got this from the Morse Twist Drill and Machine Company catalogue when I was looking for information on my 1146 tap wrench.
It shows the dimensions of the taper, tongue, keyway and key.


morse long.JPG



Morse short.JPG


A LINK to the Machinist's practical Guide. which also shows the information and other interesting stuff.
 

Sandyn

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For those interested in old books and the history of machine tools, here is the Morse catalogue. I think it's the 1915 edition.

Edit: file didn't upload, so probably too large, so here is a link to it. Download options are on the left.
 

niall Y

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Everything you wanted to know about Morse tapers, but were afraid to ask:-This shows the dimensions of different tapers. I got this from the Morse Twist Drill and Machine Company catalogue when I was looking for information on my 1146 tap wrench.
It shows the dimensions of the taper, tongue, keyway and key.


View attachment 138974


View attachment 138975

A LINK to the Machinist's practical Guide. which also shows the information and other interesting stuff.

Morse tapers work really well , where in use a force is constantly pushing them home, as when using a drill press, or drilling out on a lathe. Where they do not work at their best (as I have recently discovered) is on an unsecured chuck, I have a new chuck for my lathe, an ER32, which is such a useful piece of kit, I don't why I didn't get one years ago. As i do not have a hollow headstock on the lathe, I cannot secure it in position by screwing a bolt into its internal thread, This gives rise to the arbor falling out constantly, unless the tailstock is brought into play. A feature like the illustration - third in from the left - might certainly be of help in this instance.
Another example of the Morse taper not performing at it's best, was years ago, before I had a mortiser in the workshop,Then I used to use an attachment on my pillar drill. I had to abandon using it in the end, as the action of the auger kept pulling the Jacobs chuck ( complete with arbor), out of the quill, which to put it mildly was a right PITA.
 

Fergie 307

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Please, that is not correct. The Morse taper relies on the friction of the taper to transmit the driving force, not any contact between tang and slot.

If a person is in a situation where drive does get transmitted via the tang, that is not a normal mode of operation and either the male taper or the female taper or both are unservicable.
The tang is there for the wedge to bear against to knock it out, so you don't damage the taper, or at least that's what I was always told it was for.
 

Fergie 307

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Morse tapers work really well , where in use a force is constantly pushing them home, as when using a drill press, or drilling out on a lathe. Where they do not work at their best (as I have recently discovered) is on an unsecured chuck, I have a new chuck for my lathe, an ER32, which is such a useful piece of kit, I don't why I didn't get one years ago. As i do not have a hollow headstock on the lathe, I cannot secure it in position by screwing a bolt into its internal thread, This gives rise to the arbor falling out constantly, unless the tailstock is brought into play. A feature like the illustration - third in from the left - might certainly be of help in this instance.
Another example of the Morse taper not performing at it's best, was years ago, before I had a mortiser in the workshop,Then I used to use an attachment on my pillar drill. I had to abandon using it in the end, as the action of the auger kept pulling the Jacobs chuck ( complete with arbor), out of the quill, which to put it mildly was a right PITA.
Dead right, that's why on a mill they are fitted with a draw bar, side pressure will have them out in no time, with potentially unpleasant consequences. Even end on its not a bad idea to use a draw bar, particularly if the taper is less than perfect.
 
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