I have a lathe that lists the head stock as MT 4 1/2 in the manual. It
is a CZ-300A lathe made in china. I have found the lathe on the net, but
it now lists the head taper as MT5. I a MT 5 center, and a MT5-MT3
adapter, but they do not seem to fit it it correctly. Does anyone have
any info on what a MT 4 1/2 taper is? I have not been able to find any
adapters or anything listed in any of the catalogs for this size. Anyone
have a source for any? What would you think about reaming it out to MT5?
Thanks,
Dale
You can get sleeve adapters that convert your 4-1/2 MT into 3 MT.
They're sold new by Clausing
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for their
5914 series of lathes but you might be in for some sticker shock.
If you're patient you could probably find one on ebay.
I would forget about reaming out your current spindle to a larger taper,
that would be hard to do accurately, would weaken the spindle and overall
wouldn't be a good idea. If you want to do it yourself, I'd recommend making
your own 4-1/2 to 3 MT adapter. If you can't find a 4-1/2 to 3 adapter at a
reasonable price I beleive you can buy straight cylindrical tooling adapters
that have an internal MT 3 taper pretty cheaply. You would just need to turn
the 4-1/2 taper on the outside of one of these adapters. Check
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and
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to find these tooling adapters.
Good luck-
Paul T.
wow that's really weird
did you get an adapter to put in it when you got the lathe
can you check the actual measurements against the machinery handbook to see
if maybe it is another taper than morse
Just so you have both opinions, I disagree. I reamed out a drill press to
the next larger morse taper, no problems.
For the machining, I hope you have a taper attachment for your lathe. Do one
for practice to make sure you have the cut set just right. I'd also hold the
part in a four jaw or adjust true three jaw so you can indicate in the part
just right. This calls for careful accurate work.
If you have a morse five reamer, use it only after removing most of the
metal. Or, cut the tang off a couple morse 5 drill bits, slather with
lapping compound, and use them to lap the morse five taper in perfect.
Karl
I'm glad that worked out for you Karl, but on a lathe I would still
recommend against cutting the inside of the spindle to an oversize. You
want that spindle to be as stiff as possible since on a lathe it takes a lot
of side load when making cuts. If there was room to put in a 5 MT taper in
it at the factory without making the spindle too weak they probably would
have done so.
On a drill press you have a better chance of having this work out since the
drill press spindle doesn't see as much side load as a lathe spindle. But
just to be hard headed, I still don't like the idea of cutting the inside of
any machine spindle oversize, you're just asking for trouble.
Paul T.
You can find the 4-1/2 Morse taper in the list of ASA tapers in
Machinery's handbook. The ASA tapers took tapers from three series to
make the full set. The smallest ones are B&S taper, IIRC. The middle
range is the Morse series (with the addition of the MT 4-1/2, which
appears not to be in the other listings of Morse tapers), and then
(IIRC) Jarno tapers as the big end of the ASA series.
MT 4-1/2 is a common taper in spindles with L-00 noses, and
sufficient through diameter to handle a drawbar for 5C collets. One
example which I have is my Clausing 12x24.
You could buy one pre-made from Clausing -- but they are hardly
inexpensive. (Back when I got my lathe (about six years ago, for a
lathe made in 1957), the parts list showed the price as about $68.00,
and I doubt that they have come down since then. :-)
I've made my own adaptors (two -- one to MT-3 and one to MT-2),
once I got the taper attachment from eBay and figured out what parts
were missing and made replacements.
Set the taper attachment by running a long-stemmed indicator
along the ID of the spindle -- or by setting up a dial indicator on the
cross-slide and measuring the offset over a known distance.
Then turn the OD to the proper taper and size, and test-fit it
in the spindle -- ideally with bluing to assure that it is contacting
the full length.
Once that is right, then remove the chuck, install it in the
spindle, part off to a reasonable projection from the spindle nose,
center drill, drill through at slightly under the minor diameter, then
set the taper attachment to close to the proper setting for MT-3 (or
MT-2, as appropriate), and using a boring bar, turn the ID to close to
size, Finish up with an appropriate Morse taper finish reamer, held in a
large tap wrench, and pressed by a dead center in the tailstock (which
has been previously checked for being on center -- before you started
this project). Use a male Morse taper gauge *frequently* to verify the
depth. It is easy to take off too much.
I would suggest that you bevel both ends of the taper socket, to
reduce the chance of burs being formed from it knocking into other
things in your tool drawer) which would push the taper off center.
Also, bevel both ends of the OD as well, for the same reasons.
Good Luck,
DoN.
There was a lot of talk about boring the taper out to MT5.
If you did manage to enlarge it without ruining the spindle
you can no longer use standard accessories such as a collet adapters
that use the factor taper.
Thanks for all the info. I do have the specs on the MT 4 1/2 taper, but
have no taper attachment for the lathe. The MT 5 is a real close fit
into the taper. I am going to try to see where it is hitting. I would
even consider cutting the back off of the taper if that is where it it
hitting. The ground nose of the spindle only looks like it goes back
about 2 inches. The rest is very rough, and not machined. This is why I
thought about just reaming it out with a MT5 reamer. I am not worried
about loosing the 4 1/2 taper as I do not have any MT 4 1/2 taper stuff,
but do have some MT5 stuff that I picked up. I guess it comes down to
how I want to spend the money. An adapter for about 100.00 or a reamer
for about 100.00
By the way the newer model CZ-300A lathes have a 5mt taper in them,
so I would guess there is enough room to ream it out to MT5. I wrote the
factory in china, but have not heard anything back about getting an
adapter, or a replacement spindle with a MT5 already there.
Dale
Dale, I have a Lantaine lathe which sounds identical to yours with the
4.1/2 MT spindle. I bought it from the local High School and it came
with an adapter which is to 4 MT. The adapter is exactly 2" long,
ground to size for about 1/2" at the front and back and, obviously,
oversize in-between.
Good luck, mine seems like a sturdy lathe, certainly built heavily
enough.
Mike in BC
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