I need help to identify this taper on a bull nose

[w1vlf]

Guys,

I need help to identify a taper on a bull nose center I have.
I cannot figure what it is... Maybe I am measuring it wrong?

The small end is 1.491" in dia
The large end is 1.770 " in diameter.

I used several mikes and calipers to measure this and I get the same measurements

Looking on the net this doesn't fit into any type of taper I can find.
Is it possible that there is a segment of the taper that I am reading?

Problem is I am new to machine shop techniques and I am at a loss.

Thank you

PauLC
W1VLF

[choprboy]

You need to know more than that.. at the very least the axial taper length, to calculate taper. Keys? tangs? reference edges and relieved sections? Either end could be long or short of the official reference points as well depending on the manufacturer and end use. Glancing at a few tool taper charts.. wild guess... Brown&Sharpe?

[w1vlf]

Hello

Thank you, There is a lot more to it than just measuring the ends.

I have attached a couple of photos.

There is no tang but there is a relief at the small end.
The length of the taper is 5.346"

The difference between the large end 1.770 and the small end 1.491 = .279"
Divided by the length of the taper is .0521" per foot.

Which doesn't really help since all the Morse tapers appear to be close to .052" per foot

Here is where I am getting my data from

http://littlemachineshop.com/reference/tapers.php#Jarno


PauLC
W1VLF

[Russ Hanscom]

Definitely need to provide the distance between the two diameter measurement.

[wlw-19958]

Hi There,

Hello

Thank you, There is a lot more to it than just measuring the ends.

I have attached a couple of photos.

There is no tang but there is a relief at the small end.
The length of the taper is 5.346"

The difference between the large end 1.770 and the small end 1.491 = .279"
Divided by the length of the taper is .0521" per foot.

Which doesn't really help since all the Morse tapers appear to be close to .052" per foot

Here is where I am getting my data from

http://littlemachineshop.com/reference/tapers.php#Jarno


PauLC
W1VLF

No offense but there is a flaw in your math.

Given the data provided, your taper per foot is: 0.6262626...".

I think you meant taper per inch. This works out to be: 0.052188...".
which is closer to 0.0522" than 0.0521".

Good Luck!
-Blue Chips-
Webb

[WesHowe]

It sure looks like that would fit into a Morse Taper #5 socket. The difference in your taper measurements is about 0.0004" versus the spec (0.05262). Like all taper fits, some of the large end never fits down into the socket and the small end does not really go to the smallest end of the taper. It depends on pressure to hold it in.

[choprboy]

Previous post deleted 'curs maths is herd... But yeah as noted already your mixing inches/feet of taper. You also need to specify taper length or axial length between diameter measurement. In this case it is a small difference, but it can be significant.

Very close to Morse 4-1/2 and 5 tapers.

Other tapers:
http://www.tools-n-gizmos.com/specs/Tapers.html

[w1vlf]

Right I have to be way more careful with my units

Thank you

PaulC
W1VLF

[earlgo]

Put a very thin coat of Hi-spot Blue or even Prussian Blue Oil paint on your taper and try it in a #5 Morse socket. The blue transfer will tell you how close you are to a #5MT. The math says it is a #5.

You could but the bull nose end into the headstock socket, line up and support the outboard end with something (a steady rest might suit) and run a DTI down a known length and read the difference in radius. Then do the calculation. Centering the outboard end may be the biggest obstacle. You could read the delta R top and bottom or front and back of the shank and do an average, though. taking the readings at 180° may present another problem.

--earlgo