Newbe question
 

Just got a Nutool MC 900 lathe similar to Clarke tools and many
others..probably Chinese in origin but works well.
This is probably very obvious but....

When turning a piece say 8" by 4"diam with a view to hollowing (Vase shape
for example) I start off spindle turning to shape it up.The spur drive (4
teeth) inavriably starts to slip after a while and no amount of bashing back
in or increasing tailstock pressure seems to help?
I then mounted it on a very basic 4 jaw chuck and in conjunction with the
tailstock tried turning again but it seems impossible to centre it as before
and I therefore return it to new shape / centre.To hollow it out i removed
tailstock and tried with a small spindle gauge
to attack the end.It all flew off the chuck and thenwas impossible to
recentre on the chuck.
Is there a better way to hold such pices and how do I retain centres when
transferring from spindle to face turning.
Thanks and regards from the UK

Newbe question
 

Capt T wrote:
Just got a Nutool MC 900 lathe similar to Clarke tools and many
others..probably Chinese in origin but works well.
This is probably very obvious but....

When turning a piece say 8" by 4"diam with a view to hollowing (Vase shape
for example) I start off spindle turning to shape it up.The spur drive (4
teeth) inavriably starts to slip after a while and no amount of bashing back
in or increasing tailstock pressure seems to help?
I then mounted it on a very basic 4 jaw chuck and in conjunction with the
tailstock tried turning again but it seems impossible to centre it as before
and I therefore return it to new shape / centre.To hollow it out i removed
tailstock and tried with a small spindle gauge
to attack the end.It all flew off the chuck and thenwas impossible to
recentre on the chuck.
Is there a better way to hold such pices and how do I retain centres when
transferring from spindle to face turning.
Thanks and regards from the UK



It is very difficult to rechuck a piece so that it is spinning as before.

When I rough something like a vase, I start between centers, just to get
it somewhat round and balanced. Then I cut a tenon or rebate on what is
to be the bottom, generally a rebate so I don't have to do anything
extra to finish the bottom, and then transfer to a chuck before doing
any shaping. Make sure that the tenon or rebate is shorter than the
dovetails on the jaws. If you look closely, most jaws have a shoulder
below the dovetail that is the same diameter as the top end of the
dovetail. If your tenon or rebate reaches the shoulder on the jaws it
will not hold worth a hoot. On my Nova chucks anything deeper than 1/4"
is asking for trouble.

One other thing that you learn by trial and error, mostly error, is how
tight to chuck things. Too tight and the wood fractures and will come
off rather easily. Too loose and ditto.

I would suggest not doing vases until you have mastered hollowing out
shorter forms. Lots of leverage out there on a 8" vase. And don't be
afraid to "Cheat" and drill out most of the material.


--
Bill Berglin

"Life should not be a journey to the grave with the intention of
arriving safely in a pretty and well preserved body, but rather to skid
in broadside, thoroughly used up, totally worn out, and loudly
proclaiming, 'WOW! What A RIDE!!" ... Unknown

Newbe question
 

Thanks Bill I presume by rebate you mean drill a hole maybe 1" diam in the
base? And then expand chuck jaws to hold?
Regards

"Bill B" wrote in message
...
It is very difficult to rechuck a piece so that it is spinning as
before.

When I rough something like a vase, I start between centers, just to get
it somewhat round and balanced. Then I cut a tenon or rebate on what is
to be the bottom, generally a rebate so I don't have to do anything
extra to finish the bottom, and then transfer to a chuck before doing
any shaping. Make sure that the tenon or rebate is shorter than the
dovetails on the jaws. If you look closely, most jaws have a shoulder
below the dovetail that is the same diameter as the top end of the
dovetail. If your tenon or rebate reaches the shoulder on the jaws it
will not hold worth a hoot. On my Nova chucks anything deeper than 1/4"
is asking for trouble.

One other thing that you learn by trial and error, mostly error, is how
tight to chuck things. Too tight and the wood fractures and will come
off rather easily. Too loose and ditto.

I would suggest not doing vases until you have mastered hollowing out
shorter forms. Lots of leverage out there on a 8" vase. And don't be
afraid to "Cheat" and drill out most of the material.


--
Bill Berglin

Newbe question
 

"Capt T" wrote: (clip) To hollow it out i removed tailstock and tried with
a small spindle gauge to attack the end.It all flew off the chuck (clip)
^^^^^^^^^^^^^^^^^
Steady rest.

Newbe question
 

Capt T
Here are a couple of thoughts on what you are trying to do.
First, if your cuts are heavy and if the wood is fairly soft and green, the
spur center will start to dig into the wood and fill itself up with fibers
from the wood. If you had the drill on end you would call the spur center a
drill bit. Once it jams with those fibers, nothing will get it to hold. Take
more gentle cuts and make sure your tools are sharp.
Second, I like to use a faceplate where possible, not a chuck. It is a myth
that you can get the piece perfectly centered after putting on a tenon. A
faceplate will give superior hold and can be centered as well as a chuck
with a bit of experience.
I would start between centers and rough shape a vase or hollow form, leaving
a tenon on the bottom large enough for a faceplate. I think you are using a
3/4x16 spindle. There is a very nice 2" faceplate made for the Taig lathe
that is great for this application. It needs to be redrilled to take #14
sheet metal screws but this is easily done.
Take a look at my web site for a few more hints. There is a page on doing
hollow forms that should help.

--
God bless and safe turning
Darrell Feltmate
Truro, NS Canada
www.aroundthewoods.com

Newbe question
 

"Capt T" wrote in message
...
Thanks Bill I presume by rebate you mean drill a hole maybe 1" diam in the
base? And then expand chuck jaws to hold?

Only if you have a steady or a delicate touch. Since you're still having
problems between the centers, your touch might not be delicate enough for a
recess just yet.

I bought a two-fanged drive center, so I can make a double saw kerf and hold
it. Works better than the four-fanged. If you pay attention to the
dovetailing, you can remount perfectly centered - as long as you didn't
knock it off by compressing the tenon.

Newbe question
 

Thanks all for your help not sure what a "kerf" is but I guess a saw cut
into which a two pronged spur can be lodged to give a deeper hold? Any way
will try again when the bruises subside.
At least the kids hamsters aren`t short of bedding


Regards

Newbe question
 

On Sat, 14 Jan 2006 17:11:13 -0000, "Capt T"
wrote:

Thanks all for your help not sure what a "kerf" is but I guess a saw cut
into which a two pronged spur can be lodged to give a deeper hold? Any way
will try again when the bruises subside.
At least the kids hamsters aren`t short of bedding


Regards

Kerf is basically the "track" or "space" left by a blade when cutting.... a
narrow blade would have a thinner kerf, etc..


mac

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