he makes it all look super easy
the jam chuck is a simple concept but sometimes not so simple to implement

i need to practice on that

i am thinking the jam chuck wood should be softer than the material
that is turned

On 12/09/2015 08:25 AM, Electric Comet wrote:
he makes it all look super easy
the jam chuck is a simple concept but sometimes not so simple to implement

i need to practice on that

i am thinking the jam chuck wood should be softer than the material
that is turned

Yup. And if you go a tad undersized, you can "recover" by putting a
paper towel between the chuck and bowl. I learned that off a Raffan
video. It's always good to have the tailstock engaged of course, until
the very last...


--
Kevin Miller
Juneau, Alaska
http://www.alaska.net/~atftb
"In the history of the world, no one has ever washed a rented car."
- Lawrence Summers

On 09/12/2015 10:25 AM, Electric Comet wrote:
he makes it all look super easy
the jam chuck is a simple concept but sometimes not so simple to implement

i need to practice on that

i am thinking the jam chuck wood should be softer than the material
that is turned

I generally use the stub of whatever is left over after parting off the
turning.

Graham


--

On Wed, 9 Dec 2015 13:09:38 -0900
Kevin Miller wrote:

Yup. And if you go a tad undersized, you can "recover" by putting a
paper towel between the chuck and bowl. I learned that off a Raffan
video. It's always good to have the tailstock engaged of course,
until the very last...

i got the feeling in the conover video that he always got it right
but may be due to video editing

but really i think it is a good trick to use a towel and it depends on what
you are turning

he did not use the tailstock as it was a toy top

On Wed, 9 Dec 2015 16:00:14 -0700
graham wrote:

I generally use the stub of whatever is left over after parting off
the turning.

not sure if we are talking about the same thing

the jam chuck example i saw was a small toy top jammed into a hole
in a chucked piece

are you talking about jamming between head and tail

On 12/10/2015 07:35 AM, Electric Comet wrote:
On Wed, 9 Dec 2015 16:00:14 -0700
graham wrote:

I generally use the stub of whatever is left over after parting off
the turning.

not sure if we are talking about the same thing

the jam chuck example i saw was a small toy top jammed into a hole
in a chucked piece

are you talking about jamming between head and tail

Often, when people turn things like boxes, the stub left over after
parting off makes a good jam fit chuck. In that case you would cut the
tenon on the stub so that the piece fits over it, rather than into a hole.

Other times, it makes sense to turn a recess in the jam fit chuck and
put the piece into the hole as you describe. It just sort of varies
with the application. The idea is essentially a friction fit, either
holding on the inside or the outside of the piece depending on what
would give the best grip...

....Kevin
--
Kevin Miller
Juneau, Alaska
http://www.alaska.net/~atftb
"In the history of the world, no one has ever washed a rented car."
- Lawrence Summers

On 10/12/2015 9:35 AM, Electric Comet wrote:
On Wed, 9 Dec 2015 16:00:14 -0700
graham wrote:

I generally use the stub of whatever is left over after parting off
the turning.

not sure if we are talking about the same thing

the jam chuck example i saw was a small toy top jammed into a hole
in a chucked piece

are you talking about jamming between head and tail

If, for example, it's a box turned in endgrain, when I part off the
lower part of the box, I turn a hole in the stub left in the chuck and
jam the top of that part into the hole so that I can finish the base and
remove all signs of the parting off.
Graham



--

On Thu, 10 Dec 2015 09:37:40 -0900
Kevin Miller wrote:

Often, when people turn things like boxes, the stub left over after
parting off makes a good jam fit chuck. In that case you would cut
the tenon on the stub so that the piece fits over it, rather than
into a hole.

makes sense i will have to try it out

i did something sort of like this out of need

i made a spindle with a morse taper on both ends
one jammed into the headstock the other i put a piece of pvc pipe over
and turned a length of pvc pipe

my tailstock needed no mods and worked as is into the other pvc end

i use this same setup just to sand copper pipe on the lathe to a nice shine

On Thu, 10 Dec 2015 11:41:33 -0700
graham wrote:

If, for example, it's a box turned in endgrain, when I part off the
lower part of the box, I turn a hole in the stub left in the chuck and
jam the top of that part into the hole so that I can finish the base
and remove all signs of the parting off.

i need to get better at removing the parting marks on pieces

it makes the end product much nicer