View Full Version : 1 1/2 Morse Taper

06-23-2012, 01:54 AM
Anyone have any idea where to get these in a blank end arbor, or in fact, anything with this taper. Wanted for a Toyo ML-1 Lathe which has this spindle taper.


06-23-2012, 06:02 AM
Are you sure it's a Morse taper? The only fractional size MT I've ever heard of is a 4-1/2. It's not shown on standard MT tables but apparently it does exist but is extremely rare...

06-23-2012, 07:55 AM
Pretty sure it is. The Toyo manual says it is apparently. 13.45 is the measurement of spindle bore at the end.


06-23-2012, 08:07 AM
Hi Nev,

Never seen a 1-1/2 Morse taper either... I *guess* there's a standard for it, but can't find one in the reference books I have :( Tony's Lathes.co.uk site does list the Toyo spindle taper as 1.5MT though...

The 4-1/2 isn't actually a Morse, it's an "American standard" taper (according to my ancient Machinery's Handbook), there's no 1-1/2 in the series...
I know about the AS4.5 as my Holbrook has one as its spindle taper - easiest thing was to make a 4.5 to 3MT sleeve to use available tooling!

Have you tried a 2MT taper in it, as it's *possible* that the 1.5 is the "small end" stub of such? A careful bluing and inspection might prove/disprove this, if it is, great! Cut down a 2 to 1 sleeve and away you go, using 1MT tooling that can go in the tailstock too!

If not...Is there enough difference between your MT1.5 and a MT1 to use an adaptor bush to get into the world of available tooling? If so, you could take a 2 to 1 drill sleeve and turn (if soft enough) or grind the OD and trim it to make the bush, then use MT1 tooling, which is going to be a lot more available than (and probably a tenth the price of) MT1.5 hens' teeth!

Looking at the pics of the ML-1 on Tony's site, it should be possible to rotate the headstock (about 1.4 degrees initially) and run a finger DTI in the headstock taper to get the angle right, bolt a tool or a grinder (of some sort, even a Dremelloid might do) to the cross-slide and mount a 2 to 1 MT on a 1MT arbor of some sort (a good-quality 1MT-shank drill, even?), dialed in concentric in the chuck?

The Toyo looks a handy little machine for those tiny jobs we all have now and then - I find a 13x28 a bit large for carb' jets and the like, and the 2250 RPM top speed a bit low for the 50 thou" drills and under! I must watch out for one...

Dave H. (the other one)

06-23-2012, 08:33 AM
I think you will have to make one, they may have been the only ones to have used a MT 1.5. I was curious and found this discussion http://www.model-engineer.co.uk/forums/postings.asp?th=41757

MT 4.5 is actually fairly common as a lathe spindle...someone concerned with say drills would never notice it, but lathe manufacturers did. Some references have it, some don't. Standard modern used it as did Clausing and others. The reason for its popularity as a headstock taper was that its the smallest size that you could fit a 5C adapter inside of. a 5MT was to big for a small engine lathe and a 4MT wouldn't take the adapter.

Bob Fisher
06-23-2012, 02:57 PM
Could it be some sort of metric taper?? I don't even know if there ARE metric tapers. Just throwing it out for thought.Bob.

Jaakko Fagerlund
06-24-2012, 02:58 AM
Could it be some sort of metric taper?? I don't even know if there ARE metric tapers. Just throwing it out for thought.Bob.
Sure they exist: 1:10, 1:20, 1:25, 1:50, 1:100 and lots of others.

06-24-2012, 05:38 AM
Thanks guys. Not much time to reply now but do want to say that an MT2 taper will not even enter slightly. Starting to think it's some other sort of taper so may have to do some measuring sometime.