Ah, more newbie question for y'all. I have greatly appreciated the help
so far.

So far in my experiments, I frequently do this:

1) Turn something rough to round between centers using a spur and live
center
2) Cut a tenon on the head end using a parting tool
3) Remove spur center and replace with Talon
4) Take blank and put it in the Talon, pressing the tenon shoulder
against the jaws
5) Mount Drill chuck (with a drill) in tailstock
6) Drill a hole in blank

In (5) I would expect the "hole" from the live center in the blank to
line up quite close to the drill bit tip, assuming everything runs true.
It doesn't; the drill bit is always off center. The blank runs
*reasonably* true in this scenerio, but not perfectly. The bit is always
off center in the same direction it seems. Of course, with small bits,
this results in the bit flexing toward the little hole the live center
made and gives you a slightly oversized hole. It is a cheap lathe (a
Craftex from busy bee tools, something like Grizzly in the US).

Where am I/lathe/combo going wrong, and what would I do to get
everything lined up better?

PK

PS: The lathe has a rotating head; this is a cause of trouble, as even
tightened down strongly it seems to be able to be moved by a good bump,
i.e. catch. Could this be a cause of trouble? How would one fix it,
outside of a welder?

If you have the lathe bolted down, check to see if everthing is level and
you have not twisted the bed. This can be fixed by shimming the feet until
the tailstock matches with the headstock. Just a thought

Vernon
"Paul Kierstead" wrote in message
news
Ah, more newbie question for y'all. I have greatly appreciated the help
so far.

So far in my experiments, I frequently do this:

1) Turn something rough to round between centers using a spur and live
center
2) Cut a tenon on the head end using a parting tool
3) Remove spur center and replace with Talon
4) Take blank and put it in the Talon, pressing the tenon shoulder
against the jaws
5) Mount Drill chuck (with a drill) in tailstock
6) Drill a hole in blank

In (5) I would expect the "hole" from the live center in the blank to
line up quite close to the drill bit tip, assuming everything runs true.
It doesn't; the drill bit is always off center. The blank runs
*reasonably* true in this scenerio, but not perfectly. The bit is always
off center in the same direction it seems. Of course, with small bits,
this results in the bit flexing toward the little hole the live center
made and gives you a slightly oversized hole. It is a cheap lathe (a
Craftex from busy bee tools, something like Grizzly in the US).

Where am I/lathe/combo going wrong, and what would I do to get
everything lined up better?

PK

PS: The lathe has a rotating head; this is a cause of trouble, as even
tightened down strongly it seems to be able to be moved by a good bump,
i.e. catch. Could this be a cause of trouble? How would one fix it,
outside of a welder?

Bits which guide by the edge rather than a point run a lot more true.
Natural enough for a bit to follow the line of least resistance along
earlywood between annual rings. I've had good luck with brad points, but
the wood can also twist and flex some, so a steady is a good idea.

Does the point meet the one you made at the tailstock when you chuck up? If
not, you've got misalignment. Could be chuck, could be what it's mounted
to. A point in the headstock should meet a point in the tailstock.

"Paul Kierstead" wrote in message
news
Ah, more newbie question for y'all. I have greatly appreciated the help
so far.

So far in my experiments, I frequently do this:

1) Turn something rough to round between centers using a spur and live
center
2) Cut a tenon on the head end using a parting tool
3) Remove spur center and replace with Talon
4) Take blank and put it in the Talon, pressing the tenon shoulder
against the jaws
5) Mount Drill chuck (with a drill) in tailstock
6) Drill a hole in blank

In (5) I would expect the "hole" from the live center in the blank to
line up quite close to the drill bit tip, assuming everything runs true.
It doesn't; the drill bit is always off center. The blank runs
*reasonably* true in this scenerio, but not perfectly. The bit is always
off center in the same direction it seems. Of course, with small bits,
this results in the bit flexing toward the little hole the live center
made and gives you a slightly oversized hole. It is a cheap lathe (a
Craftex from busy bee tools, something like Grizzly in the US).

Where am I/lathe/combo going wrong, and what would I do to get
everything lined up better?

PK

PS: The lathe has a rotating head; this is a cause of trouble, as even
tightened down strongly it seems to be able to be moved by a good bump,
i.e. catch. Could this be a cause of trouble? How would one fix it,
outside of a welder?

In article , "George" george@least
wrote:

Does the point meet the one you made at the tailstock when you chuck up? If
not, you've got misalignment. Could be chuck, could be what it's mounted
to. A point in the headstock should meet a point in the tailstock.

That is what happens. Actually, never mind the drill thing; it distracts
from the problem. If I do this:
1) Rough a cylinder between centers using spur and live center
2) Cut a tenon (parting tool)
3) Remount cylinder using chuck (Talon)
4) move tailstock back to cylinder.

in (4) the tailstock live center will not line up with the old point.
Now the tail stock has some play (it is not an exact fit between the
ways), but even the play is not enough to make line up. In my mind, this
would indicate the head is not parallel to the ways; how would one go
about fixing this? Of course the chuck could be bad too, but it is much
much better built then the lathe.

PK

In article ,
"vernon" wrote:

If you have the lathe bolted down, check to see if everthing is level and
you have not twisted the bed. This can be fixed by shimming the feet until
the tailstock matches with the headstock. Just a thought

Not bolted down, but interesting thought. It has cast iron ways; can
they actually be twisted? Mind you, my lathe has a cheap stamped steel
stand, so I expect the ways tend to force the stand into some "mode",
not the other way around, but still I wonder...

Thanks for the suggestion. I might put a couple of winding sticks on
there just for fun...

PK

You can discount the information based on prejudice if you want, but what
you have here is one of the reasons why I use dovetails, not compression
holds. If you squeeze a piece of wood, it'll seek accommodation by
compressing or working against the incompressible steel. Can be so gross as
to be visible, or so subtle as to pass without notice. Try bringing up the
tailstock with the piece only supported in the chuck, then tightening the
chuck. May not be absolute, but it will restore the status quo ante.

Your problem might be exacerbated by serrations on the inside of the chuck
jaws. They're generally symmetrical, and so as likely to push away as draw
toward the established shoulder when you tighten. They also break fibers,
making a precise remount less likely. The dovetail wedges itself against
the bottom, doesn't chew fibers, and if you use it properly - snug, not
cranked to the point of depressing the wood - automatically recenters if you
dismount.

Did you put your spur center point matched up against your tailstock point?

"Paul Kierstead" wrote in message
news
In article , "George" george@least
wrote:

Does the point meet the one you made at the tailstock when you chuck up?
If
not, you've got misalignment. Could be chuck, could be what it's
mounted
to. A point in the headstock should meet a point in the tailstock.

That is what happens. Actually, never mind the drill thing; it distracts
from the problem. If I do this:
1) Rough a cylinder between centers using spur and live center
2) Cut a tenon (parting tool)
3) Remount cylinder using chuck (Talon)
4) move tailstock back to cylinder.

in (4) the tailstock live center will not line up with the old point.
Now the tail stock has some play (it is not an exact fit between the
ways), but even the play is not enough to make line up. In my mind, this
would indicate the head is not parallel to the ways; how would one go
about fixing this? Of course the chuck could be bad too, but it is much
much better built then the lathe.

PK

Should have read it before sending. It is I who am prejudiced toward
dovetails. This type of circumstance is one of the reasons for it. Inside
or outside, they grip on a broad, nondestructive face. Lots of folks
believe otherwise.

"George" george@least wrote in message
...
You can discount the information based on prejudice if you want, but what
you have here is one of the reasons why I use dovetails, not compression
holds.

Hello Paul,

You've received a number of good suggestions, all of which could be the problem.
I suspect however from what you say that the headstock is not locked down in
perfect alignment with the tailstock. I've used rotating head lathes for several
years and finally settled for a double ended Morse Taper to ensure the centering
of the lathe headstock and tailstock. When you turn between centers, it does not
matter if there is some misalignment between the tailstock and the headstock.
Remounting the turned wood into a chuck seldom mounts perfectly as several have
stated because the wood fibers compress differently at different locations on
the piece of wood. The result can throw you out of alignment. Your problem is
not really a newby problem. It is just that experienced turners expect to have
the problem and have learned ways to compensate.

If the misalignment is not too great, you can turn on the lathe before bringing
the drill up to the wood. Allow the wood to self center the drill and then lock
down the tailstock. If the offset is too large for this compensation, take a
skew chisel laying on its side and make a "V" indention in the wood large enough
to accept the end of the drill. This "V" indention will now be exactly on the
center of rotation. Now move the tailstock with the drill mounted in until the
drill aligns in this new "V" and then lock it down. Drill your hole and you
should be on center. All of this assumes, however, that you have made sure your
headstock and tailstock are in alignment before you mount the wood in the chuck.

Good luck, but don't feel this is a newby problem. Only the most expensive
lathes have perfectly aligned headstock/tailstock. With more experience you
learn how to overcome the problem with lesser quality equipment.

Fred Holder
http://www.fholder.com/

In article , Paul
Kierstead says...

Ah, more newbie question for y'all. I have greatly appreciated the help
so far.

So far in my experiments, I frequently do this:

1) Turn something rough to round between centers using a spur and live
center
2) Cut a tenon on the head end using a parting tool
3) Remove spur center and replace with Talon
4) Take blank and put it in the Talon, pressing the tenon shoulder
against the jaws
5) Mount Drill chuck (with a drill) in tailstock
6) Drill a hole in blank

In (5) I would expect the "hole" from the live center in the blank to
line up quite close to the drill bit tip, assuming everything runs true.
It doesn't; the drill bit is always off center. The blank runs
*reasonably* true in this scenerio, but not perfectly. The bit is always
off center in the same direction it seems. Of course, with small bits,
this results in the bit flexing toward the little hole the live center
made and gives you a slightly oversized hole. It is a cheap lathe (a
Craftex from busy bee tools, something like Grizzly in the US).

Where am I/lathe/combo going wrong, and what would I do to get
everything lined up better?

PK

PS: The lathe has a rotating head; this is a cause of trouble, as even
tightened down strongly it seems to be able to be moved by a good bump,
i.e. catch. Could this be a cause of trouble? How would one fix it,
outside of a welder?

"Paul Kierstead" wrote in message
news
In article , "George" george@least
wrote:
SNIP ........

in (4) the tailstock live center will not line up with the old point.
Now the tail stock has some play (it is not an exact fit between the
ways), but even the play is not enough to make line up. In my mind, this
would indicate the head is not parallel to the ways; how would one go
about fixing this? Of course the chuck could be bad too, but it is much
much better built then the lathe.

PK
===============
Paul,
Don't discount the chuck too readily. The jaws are supposed to go on in a
certain sequence. If it's new, there's a possibility that the thing wasn't
properly set up at the factory. Check on that before going any farther.

Ken Moon
Webberville, TX

George wrote:

Should have read it before sending. It is I who am prejudiced toward
dovetails. This type of circumstance is one of the reasons for it.
Inside
or outside, they grip on a broad, nondestructive face. Lots of folks
believe otherwise.

And some agree with you.

Actually George, having rough turned about 40 bowls so far (I never had a
lathe in my life until August of 2004), I very much favor dovetails. It is
easy to turn the recess and, as nearly as I can tell, they center a WHOLE
lot better than a tenon does. Before I remount it to turn the face, I
calculate the maximum depth I want to turn to so I avoid going too deep
over the dovetail. Then I'll leave the edge intact so I have a reference
point to measure from until I am done machining the interior. From this rim
I use a straight edge and a ruler to make a simple depth gauge.

It's simple, works really well and the only expense is a minor amount of
thought.

To mount the bowl on the chuck, I place the bowl face down on the lathe bed
ways, drop the el-cheapo utility chuck into the recess and expand them by
hand until snug. Then I give the chuck a quick twist with the tommy bars
and mount the whole arrangement on the headstock spindle.

To make life just a little easier on myself, I ground the edges I need into
a piece of HSS bar stock I found at work (From a broken cutter blade. So
far as work is concerned, it is junk metal. For my purposes, though, it is
'found gold'.)

Bill C.
on the western edge of Detroit, MI

Cheesehead friend and I have been discussing "feet" versus reveal. The
interior dovetail makes it easier to have a mild recurve (~1/4) to make the
piece look as if it spread from nothing visible. Too many with "feet" look
like they were set on top of something. I leave more weight in the bottom
when I sneak under 1:4 ratio, though. Can get tippy.

Tip for you if you're turning bark up warp and go. Make a real rim around
the recess, stand it an eighth or so beyond whatever reveal you've decided
on. That way after the bowl warps into final shape, you'll be able to sand
the bottom without having fatter section on the ends and thin on the sides.
Just looks better.

"anonymous" wrote in message
...
I very much favor dovetails. It is
easy to turn the recess and, as nearly as I can tell, they center a WHOLE
lot better than a tenon does. Before I remount it to turn the face, I
calculate the maximum depth I want to turn to so I avoid going too deep
over the dovetail. Then I'll leave the edge intact so I have a reference
point to measure from until I am done machining the interior. From this
rim
I use a straight edge and a ruler to make a simple depth gauge.

Paul Kierstead wrote:
1) Turn something rough to round between centers using a spur and live
center
2) Cut a tenon on the head end using a parting tool
3) Remove spur center and replace with Talon
4) Take blank and put it in the Talon, pressing the tenon shoulder
against the jaws
5) Mount Drill chuck (with a drill) in tailstock
6) Drill a hole in blank
.......
In (5) I would expect the "hole" from the live center in the blank to
line up quite close to the drill bit tip, assuming everything runs true.
It doesn't; the drill bit is always off center. The blank runs
*reasonably* true in this scenerio, but not perfectly. The bit is always
off center in the same direction it seems. Of course, with small bits,
this results in the bit flexing toward the little hole the live center
made and gives you a slightly oversized hole. It is a cheap lathe (a
Craftex from busy bee tools, something like Grizzly in the US).
......
PS: The lathe has a rotating head; this is a cause of trouble, as even
tightened down strongly it seems to be able to be moved by a good bump,
i.e. catch. Could this be a cause of trouble? How would one fix it,
outside of a welder?

Although you don't say how much inaccuracy there is in the alignment
(and even the best machines will have some tolerance) I think you maybe
expecting too much.

First of all, perfect realignment (in my experience) when you remount a
work piece is just not going to happen. In the scenario above, just
think about all the interfaces between the block of wood and tip of the
drill bit. Small innacuracies are bound to creep in so many places and
compound to make a noticeable problem. Secondly, making a lathe with a
sliding tailstock and moveable quill and getting the two axes to be in
perfect alignment is an engineering feat beyond my comprehension. Add to
that a rotating headstock and the engineering compromises that must be
made to manufacture a cheap lathe, and you are gonna be a long way from
perfection.

What can you do? Other than check the basic alignment of the headstock,
your best bet is to be sure that the tenon is is the bext possible natch
for the jaws. Choose the opitmum diameter for the jaws, where they form
a circle. If the jaws have a dovetail, make sure you cut a matching
shape in the tenon. You want the jaws to grip but not compress the wood.
All the cuts should be nice and clean. Close grained hardwood like maple
will give best results.


--
Derek Andrews, woodturner

http://www.seafoamwoodturning.com
Wedding Favors ~ Artisan Crafted Gifts ~ One-of-a-Kind Woodturning

In article ,
"Ken Moon" wrote:

Don't discount the chuck too readily. The jaws are supposed to go on in a
certain sequence. If it's new, there's a possibility that the thing wasn't
properly set up at the factory. Check on that before going any farther.

I have actually changed the jaws, so that is even more of a possibility
However, the error is always in the same direction; this is not
eccentricity, it is simply pointing wrong. I did check them over again
as well, just in case...

PK

In article , "George" george@least
wrote:

You can discount the information based on prejudice if you want, but what
you have here is one of the reasons why I use dovetails, not compression
holds.

snip some good reasons for using dovetailed recesses...

THis is good reasoning and quite informative. However, in this case we
have the following:
- I was using dry maple. Trust me, it doesn't compress much
- I don't crank on the chuck. This will happen with the lightest of
pressure.
- different pieces in different orientation always result in missing the
exact same way, i.e the error is always in the same direction.

Considering that, I would suspect it cannot be a wood compression issue.

Did you put your spur center point matched up against your tailstock
point?

Yup. But, of course, *in theory*, they could both be 30 degrees to each
other and still meet at a point; in practice, only a small error could
happen and the ends still meet. Bah. Must revisit the headstock.

In article ,
Derek Andrews wrote:

Although you don't say how much inaccuracy there is in the alignment
(and even the best machines will have some tolerance) I think you maybe
expecting too much.

LOL, I was telling a friend off in the shop just they other day; "Stop
being an engineer!" I said. Thanks for the reality check; I too need it
some days.

Unfortunately, in this case, I think I might not be expecting too much;
For example, if I was to drill out something thin walled like a pepper
mill, the drill would exit the side within 3". This is not error
measured with a vernier caliper; it is serious enough to cause trouble
when you need a reasonably parallel centered hole.

PK

In article ,
Fred Holder wrote:

I suspect however from what you say that the headstock is not locked down in
perfect alignment with the tailstock. I've used rotating head lathes for
several
years and finally settled for a double ended Morse Taper to ensure the
centering
of the lathe headstock and tailstock

Double ended morse taper?? I never knew such a beast existed; now that
would be just the ticket. I have been trying to figure out how one would
get the two parallel with each other. I will have to track one down.

If the misalignment is not too great, you can turn on the lathe before
bringing the drill up to the wood. Allow the wood to self center the drill
and then lock
down the tailstock.

Ahh, also a great idea. Never thought of that. Some things to try.

In article ,
Paul Kierstead wrote:

Many thanks for the help on this; it is a great help!

PK

Ah yes, I was also going to suggest this "Biological impossibility" device.
Those with rotating headstocks shouldn't be without them.

How about loosening the jaws on the chuck, sliding the nose of the tail
center into gripping position, and tightening both grip and jaw alignment
with it as a reference?

"Paul Kierstead" wrote in message
news
In article ,
Fred Holder wrote:

I suspect however from what you say that the headstock is not locked
down in
perfect alignment with the tailstock. I've used rotating head lathes for
several
years and finally settled for a double ended Morse Taper to ensure the
centering
of the lathe headstock and tailstock

Double ended morse taper?? I never knew such a beast existed; now that
would be just the ticket. I have been trying to figure out how one would
get the two parallel with each other. I will have to track one down.

If the misalignment is not too great, you can turn on the lathe before
bringing the drill up to the wood. Allow the wood to self center the
drill
and then lock
down the tailstock.

Ahh, also a great idea. Never thought of that. Some things to try.

On Mon, 22 Nov 2004 23:23:56 -0500, Paul Kierstead wrote:

Double ended morse taper?? I never knew such a beast existed; now that
would be just the ticket. I have been trying to figure out how one would
get the two parallel with each other. I will have to track one down.

You can get one at Woodcraft.com.

Peter Teubel
Milford, MA
http://www.revolutionary-turners.com

Paul Kierstead wrote:
Unfortunately, in this case, I think I might not be expecting too much;
For example, if I was to drill out something thin walled like a pepper
mill, the drill would exit the side within 3". This is not error
measured with a vernier caliper; it is serious enough to cause trouble
when you need a reasonably parallel centered hole.


I don't know if anyone has suggested this already, but put centers in
both headstock and tailstock. Retract the quill and bring the tailstock
up, lock everthing and check for alignment. Now backoff the tailstock
and extend the quill and check for alignment again. That will tell you
if there is a problem with the tailstock. Measure any errors, and note
if they are vertical or horizontal.

If the tailstock seems ok, the only way I can think of to test the
rotating headstock is this. Rough out a cylinder, maybe 2x6, between
centers. Now put the cylinder in the chuck, true it up and make a nice
face on the end. Mark the center of the end face with the tip of a skew
chisel, and bring up the tailstock center and check for alignment. Do
this with both the quill in and out. Now carefully part off the
cylinder, face it off, mark the center and test for alignment.

--
Derek Andrews, woodturner

http://www.seafoamwoodturning.com
Wedding Favors ~ Artisan Crafted Gifts ~ One-of-a-Kind Woodturning

Double ended morse taper??
You can get one at Woodcraft.com.

Also at Packard Woodworks both #1 and #2 Morse taper.

In article s.com,
"Harry B. Pye" wrote:

Double ended morse taper??
You can get one at Woodcraft.com.

Also at Packard Woodworks both #1 and #2 Morse taper.

Thanks for the pointer! I ordered one from Packard ... I think. I placed
the order, but there has been no confirmation email, your order has been
shipped, that kind of thing. Maybe I'll have to drop them an email.

PK

They don't, but their word has always been good.

"Paul Kierstead" wrote in message
news

Thanks for the pointer! I ordered one from Packard ... I think. I placed
the order, but there has been no confirmation email, your order has been
shipped, that kind of thing. Maybe I'll have to drop them an email.

PK

Paul,
Packard is a family owned and run operation. It's a little larger than
just Brad and Debbie, but not much. They are deeply into woodturning but
not computers. This has its disadvantages, such as lack of automated
confirmations and what is a rather primitive electronic ordering
system--if they are out of town for a few days, or celebrating the
holidays, you won't hear from them. But, and this is a big but, they
make up for this,in spades, by really understanding woodturning and
having a genuine interest in fellow woodturners---and they show this
year in and year out.

So by all means drop them an email, for sometimes even with the best
intentions things go awry, but be comfortable that you are dealing with
great people, and that they will treat you right.

Lyn

Paul Kierstead wrote:
In article s.com,
"Harry B. Pye" wrote:


Double ended morse taper??

You can get one at Woodcraft.com.

Also at Packard Woodworks both #1 and #2 Morse taper.


Thanks for the pointer! I ordered one from Packard ... I think. I placed
the order, but there has been no confirmation email, your order has been
shipped, that kind of thing. Maybe I'll have to drop them an email.

PK