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Help identifying taper on MacGregor Gourlay lathe

mega arc 5040dd

Aluminum
Joined
Apr 17, 2012
Location
Saskatchewan, Canada
I have what I believe to be a MacGregor Gourlay lathe and am having trouble identifying the tapers in the headstock and tail stock. I tested two centers in the tail stock and they both seemed to fit right one is a newer one and one is a very old one that either came with this lathe or a barnes 13 I used to have. I then measure both centers. The new one is an MT2 and the old one I believe is an MT2 but could just as easily be a jarno taper and thats where my problems begin.

Form what I can tell from my machineries handbook 6th edition jarno and MT2 are only .002" per foot different. I have no way to measure the taper accurately enough to be able to tell the difference. That brings me to my first question can a MT2 center or drill be used in a jarno taper since they are that close? If not would I be able to tell for sure if the tail stock was a jarno taper just by trying an MT2 center in it.

My next question is the head stock. I thought that if i measured the dead center that came with the lathe it would tell me if the taper is MT or jarno and then answer my question about the tail stock. When I measured it I got roughly .519" taper per foot. That doesn't match taper i could find in machineries handbook 6th or 29th editions. I am aware that it could be a random taper that the manufacturer just decided on and since I have a center for it it doesn't really matter but thought I would as if anyone knows what it is.

Any advice would be a big help this is one of the last things I have left to figure out on this lathe before it is ready to make chips finally.
 
Might be useful

Standard Tapers

Head stock taper quite often is what ever maker likes - since all it fits is the sleeve that holds a standard taper center This sleeve was sold with the lathe.

Tail stock could be MT2 which is .5994 per foot, very close to Jarno - except for the fact that there are no Jarnos that are .700 on the big end - like the MT2 is
 
Put some prussian blue on the new MT2 center and put it in the tailstock and revolve it. That will show if you have full contact or not. You can also run a dial indicator in the bore and measure the taper in 1" of travel of the carriage.
 
I blued up the MT3 and checked it in the tail stock. It had good contact up until about a half inch from the large end. I also measured the opening on the tail stock and it came in and .700" give or take a few thou.
 
I blued up the MT3 and checked it in the tail stock. It had good contact up until about a half inch from the large end. I also measured the opening on the tail stock and it came in and .700" give or take a few thou.

welll... yeah.. "Wear" is not include in any taper standard I have ever seen.

:)

If anyone EVER used a jarno in a TS, I'm ignorant of that too, simplest of reasons:

B&S taper shank twist drills have existed, but so long ago they are essentially extinct. Morse won the taper wars for drills. B&S won it for mills. Jarno-ass drills were never seen. "As Far As I know".

HS end, spindle taper is confusing UNLESS made for a collet family. Because .. damned near ALL of them ever made use only a partial run of any given taper.

And it can be "selected" anywhere from within the full run.

Eg: close to small end, close to big end, close to middle, damned seldom exactly any of those.

Wherever it WORKED for the maker, IOW, An adapter taken as a necessity, regardless.

Plan to make an adapter for yerself. Good character builder!

:)
 
welll... yeah.. "Wear" is not include in any taper standard I have ever seen.

:)

If anyone EVER used a jarno in a TS, I'm ignorant of that too, simplest of reasons:

B&S taper shank twist drills have existed, but so long ago they are essentially extinct. Morse won the taper wars for drills. B&S won it for mills. Jarno-ass drills were never seen. "As Far As I know".

HS end, spindle taper is confusing UNLESS made for a collet family. Because .. damned near ALL of them ever made use only a partial run of any given taper.

And it can be "selected" anywhere from within the full run.

Eg: close to small end, close to big end, close to middle, damned seldom exactly any of those.

Wherever it WORKED for the maker, IOW, An adapter taken as a necessity, regardless.

Plan to make an adapter for yerself. Good character builder!

:)

Some of the old manufacturers used jarno in their tail stocks Barnes did on some of their lathes. I shouldn't need to make an adapter for the headstock as it came with a center that fits. It's the tail stock I will have to figure out if I can use the MT2 tooling I own already or if it will need some sort of adapter or more likely a new quill. Not a job I want to have to try and take on right now but possible a good winter project.
 
Some of the old manufacturers used jarno in their tail stocks Barnes did on some of their lathes. I shouldn't need to make an adapter for the headstock as it came with a center that fits. It's the tail stock I will have to figure out if I can use the MT2 tooling I own already or if it will need some sort of adapter or more likely a new quill. Not a job I want to have to try and take on right now but possible a good winter project.

Barnes were more of an experimental R&D laboratory than a manufacturer!

:)

ALL TS quills of "a certain age" can benefit from refurb if not renewal.
I'm not a believer in sticking DRILLS in them, though.

Just set yerself up to drill with the carriage instead. THEN you have:

- FAST peck and/or clearing of chip.

- Power feeds.

- No more damage to the TS or its anti-rotation key.

and yer TS lives longer to support a centre more accurately for turning operations.
 








 
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