morse taper

[tomrux]

hey people

how do i calculate how far over to push the tail stock to cut a morse taper.


TIA

Tom

[BillTodd]

Tapers, Morse and most other imperial ones, are specified in inches per foot (or per inch) on diameter .

All you need to do is turn the  work parallel, then measure two points at precisely 2.0000" or 3.0000" apart and adjust the tail stock over the correct amount. e.g. 2.0000  x 0.04995" /2  = 0.04995 for an mt2. (Yes, they really are specified to 5 decimal places)

Mt1 = 0.04988 "/"
mt2 = 0.04995
mt3 = 0.05019

Bill

[tomrux]

sort of thought morse taper was same angle just larger for the different sizes ???????

kind of lost here.

trying to turn an adapter to hold and centre a chuck to an rt.

tom

[Bogstandard]

If you are not really into fine machining, you might be causing yourself a bucketload of trouble by offsetting your tailstock, as it will need to be put back to spot on after you have finished, and that can be a big job in itself.

I don't know which lathe you have, but if you can get a long enough cut on your topslide, say 3" to 3.5" then it might be easier to do it that way. The first part of this post shows an easy way to cut a taper to match one you already have (forget the grinding part).

http://madmodder.net/index.php?topic=1993.0

I usually keep in stock a few blank end arbors to do the sorts of thing you are attempting, they are rather cheap and save all the hassle of cutting the tapers.

I know you are from the Antipodes, but if you can source them over there, it will save you a lot of time and money. This is what I am on about.

http://www.arceurotrade.co.uk/Catalogue/Blank-End-Arbors


Bogs

[Chuck in E. TN]

Tomrux,
I just made such an adapter for my Vertex RT.
I turned an MT2 taper on my Micromark 7x14 without offsetting the tailstock. It was tight, and I had to make the tapered cut in stages. I checked progress with an MT3 to MT2 sleeve, until the taper was as long as I needed. I did not measure anything while turning the actual taper.
I set up the topslide angle by chucking my tailstock drill chuck in my 4 jaw by its nose and used a dti to adjust the angle for zero deflection when moving the topslide. Pictures of the completed taper here:

The lathe is still set up as I want to make another, I could take more pictures if you like.

[BillTodd]

sort of thought morse taper was same angle just larger for the different sizes ???????

Thought as much  

trying to turn an adapter to hold and centre a chuck to an rt.

tom

You can probably get away with a shorter than standard taper on an RT, so cutting with the top-slide is probably easier
 
So first determine which Morse taper you have -  The gauge line is the diameter of  hole at end of the socket so measure this:

MT1 = 0.4750"
MT2 = 0.7000"
MT3 = 0.9380"

The simplest way to set the top-slide is to dial it in with known good taper  mounted between centres:

Put a bit of scrap in the chuck turn it to a sharp point then put a centre in the tail stock and make sure the two align with each other point to point (if you don't check the setting of the tail stock first there's no point in buggering about with the rest of it)

Mount a dial gauge on the top-slide, set the height so the tip is exactly on the point you've just cut and the shaft is level with the centre line.

Turn the scrap around in the chuck, face it and drill a centre hole.  Mount your MT? good centre with the point in the centre hole and, in the hole in the back of the good centre, a dead centre in the tail stock.

Set the top slide to run roughly parallel with the face of the Morse taper, run it up and down checking with the dial gauge and tapping in back and forth (for a couple of hours ;)) until it's right.

[airbus]

I wanted to make some MT3 arbors for the milldrill and came up with idea.

I bought a $3 laser pointer and made a nylon tube holder with flats on the outside and drilled a neat fit to the pointer,
insert the pointer into nylon body and lightly clamp in tool post

My lathe toolpost is 22 feet from the garage wall and my computer tells me the angle of 3MT over that distance  is 188.2mm
which is marked on yellow magnetic material.

Turn on the laser and move the magnetic marker or the saddle or both to line up one of the markers, then adjust the angle
of the topslide (laser beam) to the second marker.

[BillTodd]

Neat