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  #1   Report Post  
Greg G.
 
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Default (Q) How to modify a roughing gouge to cut bowl interiors, Sorby Hollowmaster and Tool Rests


Got my first lathe Friday, and turned a green cherry limb into a
covered vessel. I *really* need to get some books...

It turned out pretty nice, what with the contoured, dished top, edge
beading, and a thin knob with a dished top. This is some cool stuff!
I just made it up as I went along. I'll post a pix when SWMBO returns
from CA.

Anyway, in the process of roughing out the interior of the container,
I discovered that it is not advisable to use a standard roughing
gouge. It seems to grab quite forcefully and gives the general
impression of being quite dangerous. I ended up using a parting tool
to do most of the excavation. I don't have a curled bowl rest, as no
one in the area seems to carry one for a Mini-lathe with 5/8" posts.
The container is only 2 1/4" deep, so I placed the straight rest as
close as I could, but it was still an eerie handful.

My questions (finally!) a

Is there a website or other source for grinding your own custom tool
profiles. I have several extra gouges and such that I could modify
into more appropriate tools for excavating vessels. Are 100 grit
white wheels OK for this?

Also, what is the general consensus on the Sorby Hollowmaster?
I am primarily interested in small, deep thinwall vessels and
segmented bowls/vessels.

And what about the Woodcraft Tool Rest system. The straight tool
rests look like finger eaters, but the curved rests seems OK.

I DAGS, but nothing helpful.

Thanks,

Greg G.
  #2   Report Post  
Denis Marier
 
Posts: n/a
Default


Check the following. They have impressive charts showing the different
angle for different woodturning tools.
CMW Turning Tips - August 2002
from Michael O'Donnell's Tools of the Trade
http://www.carolinamountainwoodturne...s/sizing.shtml

Good luck


Got my first lathe Friday, and turned a green cherry limb into a
covered vessel. I *really* need to get some books...

It turned out pretty nice, what with the contoured, dished top, edge
beading, and a thin knob with a dished top. This is some cool stuff!
I just made it up as I went along. I'll post a pix when SWMBO returns
from CA.

Anyway, in the process of roughing out the interior of the container,
I discovered that it is not advisable to use a standard roughing
gouge. It seems to grab quite forcefully and gives the general
impression of being quite dangerous. I ended up using a parting tool
to do most of the excavation. I don't have a curled bowl rest, as no
one in the area seems to carry one for a Mini-lathe with 5/8" posts.
The container is only 2 1/4" deep, so I placed the straight rest as
close as I could, but it was still an eerie handful.

My questions (finally!) a

Is there a website or other source for grinding your own custom tool
profiles. I have several extra gouges and such that I could modify
into more appropriate tools for excavating vessels. Are 100 grit
white wheels OK for this?

Also, what is the general consensus on the Sorby Hollowmaster?
I am primarily interested in small, deep thinwall vessels and
segmented bowls/vessels.

And what about the Woodcraft Tool Rest system. The straight tool
rests look like finger eaters, but the curved rests seems OK.

I DAGS, but nothing helpful.

Thanks,

Greg G.



  #3   Report Post  
Greg G.
 
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Default

Denis Marier said:

Check the following. They have impressive charts showing the different
angle for different woodturning tools.
CMW Turning Tips - August 2002
from Michael O'Donnell's Tools of the Trade
http://www.carolinamountainwoodturne...s/sizing.shtml

Good luck


Thanks - This is perfect information for grinding my own custom tools!
Seems he specializes in the same things I am interested in turning.


Greg G.
  #4   Report Post  
Barry N. Turner
 
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If your bowl/vessel/container is only a couple of inches deep, the standard
tool rest would probably work just fine. The real problem is in your choice
of turning tools. You need to invest in a good quality 3/8" bowl gouge with
a side or fingernail grind, then learn how to use it.

Get a good book/video, take a class or find someone to give you a few
lessons. It's very important to "get started right" and not develop bad
habits that you will have to unlearn later.

I admire your tenacity for using a parting tool to clear the waste from the
interior of your bowl, but there are much better ways to do it. Even a
sharp 1/2" roundnose scraper would be better than a parting tool.

A roughing gouge really has no place in bowl turning. You might be able to
get by roughing the outside of a small bowl or vessel with one, but even
then, it's better done with a bowl gouge. Good luck.

Barry




Greg G. wrote in message
...

Got my first lathe Friday, and turned a green cherry limb into a
covered vessel. I *really* need to get some books...

It turned out pretty nice, what with the contoured, dished top, edge
beading, and a thin knob with a dished top. This is some cool stuff!
I just made it up as I went along. I'll post a pix when SWMBO returns
from CA.

Anyway, in the process of roughing out the interior of the container,
I discovered that it is not advisable to use a standard roughing
gouge. It seems to grab quite forcefully and gives the general
impression of being quite dangerous. I ended up using a parting tool
to do most of the excavation. I don't have a curled bowl rest, as no
one in the area seems to carry one for a Mini-lathe with 5/8" posts.
The container is only 2 1/4" deep, so I placed the straight rest as
close as I could, but it was still an eerie handful.

My questions (finally!) a

Is there a website or other source for grinding your own custom tool
profiles. I have several extra gouges and such that I could modify
into more appropriate tools for excavating vessels. Are 100 grit
white wheels OK for this?

Also, what is the general consensus on the Sorby Hollowmaster?
I am primarily interested in small, deep thinwall vessels and
segmented bowls/vessels.

And what about the Woodcraft Tool Rest system. The straight tool
rests look like finger eaters, but the curved rests seems OK.

I DAGS, but nothing helpful.

Thanks,

Greg G.



  #5   Report Post  
Greg G.
 
Posts: n/a
Default

Barry N. Turner said:

If your bowl/vessel/container is only a couple of inches deep, the standard
tool rest would probably work just fine. The real problem is in your choice
of turning tools. You need to invest in a good quality 3/8" bowl gouge with
a side or fingernail grind, then learn how to use it.


Yes, I discovered that almost immediately! I subsequently used what I
had at hand. I have been studying bowl gouges and grinds this night.
Being a newbie, I have a limited number of tools in my arsenal.

I'm still trying to figure out what this LDD thing is everyone is
making clandestine references to...

Get a good book/video, take a class or find someone to give you a few
lessons. It's very important to "get started right" and not develop bad
habits that you will have to unlearn later.


I plan to, as soon as the library opens. It's Sunday here - nothing's
open. I have enough "bad habits" as it is. ;-)

I admire your tenacity for using a parting tool to clear the waste from the
interior of your bowl, but there are much better ways to do it. Even a
sharp 1/2" roundnose scraper would be better than a parting tool.


It took a while & seemed rather inefficient - but I had one. :-\

A roughing gouge really has no place in bowl turning. You might be able to
get by roughing the outside of a small bowl or vessel with one, but even
then, it's better done with a bowl gouge. Good luck.


It worked fine on the straight exterior but is a definite no-no on the
inside/endgrain. This was actually a lidded vessel, not a bowl.

Thanks,


Greg G.


  #6   Report Post  
Lobby Dosser
 
Posts: n/a
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Greg G. wrote in :


I'm still trying to figure out what this LDD thing is everyone is
making clandestine references to...


Elixer of Life.

L 'but one' D
  #7   Report Post  
George
 
Posts: n/a
Default

Take the "shallow-fluted gouge" idea and apply it further back, as in
http://www.woodcentral.com/newforum/grinds.shtml the Ellsworth detail
gouge. I like more beef under the point for boring, but this sucker will
run right into endgrain and cut, on the sides, center to rim or rim to
center. Keep the rest low to have the shavings clear down the flute by
gravity. It's even got enough steel to reach out a bit over the rest. Hog
at will, then put the nose way up to shear a clean wall, remembering any
taper to avoid picking up ends.

I even use in cross-grain situations with access too narrow to use my bowl
gouges, but be ready for some truly great force on the rest and handle as
you cut a 3/4 wide face.

Greg G. wrote in message
...
Denis Marier said:

Check the following. They have impressive charts showing the different
angle for different woodturning tools.
CMW Turning Tips - August 2002
from Michael O'Donnell's Tools of the Trade
http://www.carolinamountainwoodturne...s/sizing.shtml

Good luck


Thanks - This is perfect information for grinding my own custom tools!
Seems he specializes in the same things I am interested in turning.


Greg G.



  #8   Report Post  
Greg G.
 
Posts: n/a
Default

George said:

Take the "shallow-fluted gouge" idea and apply it further back, as in
http://www.woodcentral.com/newforum/grinds.shtml the Ellsworth detail
gouge. I like more beef under the point for boring, but this sucker will
run right into endgrain and cut, on the sides, center to rim or rim to
center. Keep the rest low to have the shavings clear down the flute by
gravity. It's even got enough steel to reach out a bit over the rest. Hog
at will, then put the nose way up to shear a clean wall, remembering any
taper to avoid picking up ends.


Thanks for the advice. I found your reference earlier today from
another link from another page, from a link from another page... ;-)

Good info, I actually saved the contents to the hard drive, as sites
sometimes disappear without warning.

I even use in cross-grain situations with access too narrow to use my bowl
gouges, but be ready for some truly great force on the rest and handle as
you cut a 3/4 wide face.


Not sure if I'm ready for 3/4" wide boring cuts in either end-grain or
cross-grain. But in time...

I am primarily interested in reducing/eliminating the possibility of
catching/hanging while clearing out interiors. I found that to be a
most disconcerting experience - and one that could destroy a piece,
and possibly body parts as well.


Greg G.
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Bob Darrah
 
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I had never seen a shortcut to a Newsgroup message, before. I duplicated
what you did with a message from another newsgroup but had to copy to Word
and add News: to the front. Is there an easier way of doing it?

Thanks,

Bob Darrah
West Linn, Oregon


"Lobby Dosser" wrote in message
news:nbnad.332$MY.100@trnddc03...
Greg G. wrote in :


I'm still trying to figure out what this LDD thing is everyone is
making clandestine references to...


Elixer of Life.

L 'but one' D



  #10   Report Post  
Greg G.
 
Posts: n/a
Default

Bob Darrah said:

I had never seen a shortcut to a Newsgroup message, before. I duplicated
what you did with a message from another newsgroup but had to copy to Word
and add News: to the front. Is there an easier way of doing it?


It's an option in XNews and many other newsreaders.
AFAIK not in Outhouse, however.

Not really recommended, as some newsreaders, notably Outhouse, choke
on it - or it forces a "retrieve all message headers" command, which
on a dial-up, could take quite a while.

FWIW,

Greg G.


  #11   Report Post  
Greg G.
 
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Lobby Dosser said:

Greg G. wrote in :


I'm still trying to figure out what this LDD thing is everyone is
making clandestine references to...


Elixer of Life.


OK, I figured it out. Hardly fits your definition. ;-)

L 'but one' D


So that would make you just "Liquid Detergent", eh?


Greg G.
  #12   Report Post  
Joe Fleming
 
Posts: n/a
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Greg,

To add to what others have said......

Buy the Keith Rowley book: "Woodturning: A Foundation Course".
Consider Richard Raffan's book: "Turning Wood". Both are excellent
references. Consider a bowl-turning video or two: "Bowl Turning" by
John Jordan and Del Stubbs' bowl video are excellent. Consider these
other reference items too: "Turning Green Wood" by Michael O'Donnell
and "The Aesthetics and Properties of Wood" video by John Jordan.
Finally, for hollow turning, consider David Ellsworth's video #3 on
hollow turning and John Jordan's "Hollow Turning" video.

If you live near a town with an AAW (American Association of
Woodturner's - assuming you are in the USA) chapter, you should join
and get the veterans there to give you assistance. I have rarely met
a woodturner that didn't want to help. If you live near a Woodcraft
store, go there and take lessons. If you join the AAW, you will get a
roster of members and you may find someone close by to offer
assistance. There is hardly any reason to go it alone.

Finally, be careful. What you described as your initial efforts
scared the dickens out of me. Don't let your enthusiasm get yourself
hurt. If you don't have the correct tool, be patient and wait until
you get it. Using the wrong tool can be dangerous - especially
without knowing why particular tools are designed the way they are.
Also, don't attempt to turn with a tool until you have been taught
(video, book or real person) how to use it. You have a life time to
turn. Make sure it is a long one. :-)

Joe Fleming - San Diego
=================================

Greg G. wrote in message . ..
Got my first lathe Friday, and turned a green cherry limb into a
covered vessel. I *really* need to get some books...

It turned out pretty nice, what with the contoured, dished top, edge
beading, and a thin knob with a dished top. This is some cool stuff!
I just made it up as I went along. I'll post a pix when SWMBO returns
from CA.

Anyway, in the process of roughing out the interior of the container,
I discovered that it is not advisable to use a standard roughing
gouge. It seems to grab quite forcefully and gives the general
impression of being quite dangerous. I ended up using a parting tool
to do most of the excavation. I don't have a curled bowl rest, as no
one in the area seems to carry one for a Mini-lathe with 5/8" posts.
The container is only 2 1/4" deep, so I placed the straight rest as
close as I could, but it was still an eerie handful.

My questions (finally!) a

Is there a website or other source for grinding your own custom tool
profiles. I have several extra gouges and such that I could modify
into more appropriate tools for excavating vessels. Are 100 grit
white wheels OK for this?

Also, what is the general consensus on the Sorby Hollowmaster?
I am primarily interested in small, deep thinwall vessels and
segmented bowls/vessels.

And what about the Woodcraft Tool Rest system. The straight tool
rests look like finger eaters, but the curved rests seems OK.

I DAGS, but nothing helpful.

Thanks,

Greg G.

  #13   Report Post  
Lobby Dosser
 
Posts: n/a
Default

"Bob Darrah" wrote in
:

I had never seen a shortcut to a Newsgroup message, before. I
duplicated what you did with a message from another newsgroup but had
to copy to Word and add News: to the front. Is there an easier way of
doing it?

Thanks,

Bob Darrah
West Linn, Oregon


"Lobby Dosser" wrote in message
news:nbnad.332$MY.100@trnddc03...
Greg G. wrote in :


I'm still trying to figure out what this LDD thing is everyone is
making clandestine references to...


Elixer of Life.

L 'but one' D




Never noticed that before! Apparently my newsreader does it automagicaly.

LD
  #14   Report Post  
Lobby Dosser
 
Posts: n/a
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Greg G. wrote in news
Bob Darrah said:

I had never seen a shortcut to a Newsgroup message, before. I
duplicated what you did with a message from another newsgroup but had
to copy to Word and add News: to the front. Is there an easier way of
doing it?


It's an option in XNews and many other newsreaders.
AFAIK not in Outhouse, however.

Not really recommended, as some newsreaders, notably Outhouse, choke
on it - or it forces a "retrieve all message headers" command, which
on a dial-up, could take quite a while.


Thanks for pointing that out. I'll be changing the configuration.

LD


FWIW,

Greg G.


  #15   Report Post  
Lobby Dosser
 
Posts: n/a
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Greg G. wrote:

Lobby Dosser said:

Greg G. wrote in :


I'm still trying to figure out what this LDD thing is everyone is
making clandestine references to...


Elixer of Life.


OK, I figured it out. Hardly fits your definition. ;-)

L 'but one' D


So that would make you just "Liquid Detergent", eh?


Or just slippery!



Greg G.




  #17   Report Post  
JoanD'arcRoast
 
Posts: n/a
Default

In article , Greg G. wrote:

Got my first lathe Friday, and turned a green cherry limb into a
covered vessel. I *really* need to get some books...

It turned out pretty nice, what with the contoured, dished top, edge
beading, and a thin knob with a dished top. This is some cool stuff!
I just made it up as I went along. I'll post a pix when SWMBO returns
from CA.

Anyway, in the process of roughing out the interior of the container,
I discovered that it is not advisable to use a standard roughing
gouge. It seems to grab quite forcefully and gives the general
impression of being quite dangerous. I ended up using a parting tool

snip

An friend of a friend [yeah, I know it sounds like BS, but it's true]
by the name of Terry from Atlanta, snapped a roughing gouge right off
at the tang doing what your header suggests.

Sounds like a great idea to put a fingernail grind on a roughing gouge,
but I think you must seriously resist the urge to reach the roughing
gouge very far over the tool rest for hollowing...

Look at how much more massive a big bowl gouge is where it enters the
handle.

I'm not suggesting it can't be done, just that your technique had
better be pretty darn flawless. Just think of the snapped off business
end of a roughing gouge cartwheeling out of the throw zone -- sounds
like a Sam Peckinpah movie shot.

yikes!
-j
  #18   Report Post  
Greg G.
 
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Lobby Dosser said:

(Joe Fleming) wrote:


To add to what others have said......

Buy the Keith Rowley book: "Woodturning: A Foundation Course".
Consider Richard Raffan's book: "Turning Wood". Both are excellent
references. Consider a bowl-turning video or two: "Bowl Turning" by
John Jordan and Del Stubbs' bowl video are excellent. Consider these
other reference items too: "Turning Green Wood" by Michael O'Donnell
and "The Aesthetics and Properties of Wood" video by John Jordan.
Finally, for hollow turning, consider David Ellsworth's video #3 on
hollow turning and John Jordan's "Hollow Turning" video.


Second the opinion on Rowley's book! He also has a video of the same name
as the book (IIRC), but he does get a wee bit monotonish and I have nodded
off a cuple times when watching it. Raffan's books and videos are also
good. If you can buy one book, buy Rowley; good solid, safe, fundamentals.

LD


Thanks for the pointers, guys!


Greg G.
  #19   Report Post  
Greg G.
 
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Default

Joe Fleming said:

Buy the Keith Rowley book: "Woodturning: A Foundation Course".
Consider Richard Raffan's book: "Turning Wood". Both are excellent
references. Consider a bowl-turning video or two: "Bowl Turning" by
John Jordan and Del Stubbs' bowl video are excellent. Consider these
other reference items too: "Turning Green Wood" by Michael O'Donnell
and "The Aesthetics and Properties of Wood" video by John Jordan.
Finally, for hollow turning, consider David Ellsworth's video #3 on
hollow turning and John Jordan's "Hollow Turning" video.


Thanks, Joe,
I'll look into the books. I'm not big on videos, but if the local
library has a copy, I'll look at those as well. I tend to buy things
that serve as permanent reference material - and borrow the others.

Finally, be careful. What you described as your initial efforts
scared the dickens out of me. Don't let your enthusiasm get yourself
hurt. If you don't have the correct tool, be patient and wait until
you get it. Using the wrong tool can be dangerous - especially
without knowing why particular tools are designed the way they are.
Also, don't attempt to turn with a tool until you have been taught
(video, book or real person) how to use it. You have a life time to
turn. Make sure it is a long one. :-)


Scared me as well - but I only tried it once. It was quite obviously
the incorrect tool and method to use. I stay clear of the "throw
zone" - hard NOT to do when clearing interiors. It's a small Jet
mini-lathe, so the probability of serious injury should be somewhat
reduced. I did have the sense to keep the rest properly positioned,
and to steer clear of obvious dangers. I just didn't think about the
edge profile causing a catch on end-grain. I do understand the
concepts of positioning the angle of the tool so that hangs are
deflected out of the work, and not into it.

And yes, it took me a minute to figure why certain tools are designed
the way they are. I guess you can't outdo 200 years of experience and
tool evolution in 10 minutes.

Thanks again,

Greg G.
  #20   Report Post  
Greg G.
 
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JoanD'arcRoast said:

An friend of a friend [yeah, I know it sounds like BS, but it's true]
by the name of Terry from Atlanta, snapped a roughing gouge right off
at the tang doing what your header suggests.


I'm in Atlanta, but I don't know of him. ;-)
I hope you don't now refer to him as one-eye... :-\

Sounds like a great idea to put a fingernail grind on a roughing gouge,
but I think you must seriously resist the urge to reach the roughing
gouge very far over the tool rest for hollowing...

Look at how much more massive a big bowl gouge is where it enters the
handle.


This is true. This is a mini-lathe turning small vessels, so forces
would be reduced somewhat over large pieces and more powerful lathes.
But I suppose I should try a standard bowl gouge before moving on to
custom mods.

Thanks,

Greg G.


  #21   Report Post  
Lobby Dosser
 
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Greg G. wrote:

It's a small Jet
mini-lathe, so the probability of serious injury should be somewhat
reduced.


Greg,

The degree of injury is related to the speed of the lathe and the mass of
the object thrown, not the size of the lathe. IIRC, the Jet mini has a
speed range of about 500-3000, so you are working in the same speed
range as much larger lathes. The prime difference between the mini and
larger lathes is the size of object that can be turned. But, a 4-6 ounce
chunk of wood flying off a mini running at 3000rpm has the same injury
potential as the same size chunk flying off a larger lathe at the same
speed.

Someone once said that the difference between a table saw and a lathe is
the lathe can kill you. I've got an old face shield I keep as a reminder
of the dangers of turning. It has a nice gouge from a 4 ounce or so chunk
of bowl right about where the edge of my scalp would have been had I not
been wearing it and even with the protection, the impact was enough to
make me dizzy - like getting hit with a bullet while wearing a
bulletproof vest.

I don't want to rattle you, but you need to be as concerned about safety
on your mini as you would on a larger lathe. The safety habits you build
now will last you forever.

Have fun, but have fun safely!

LD
  #22   Report Post  
George
 
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Greg, since you will be limited to cutting over the bed, you might be
interested in the information at:
http://personalpages.tds.net/~upgeorge/index.html

Never put yourself in the throw zone. You can cut as well if not better
from outside.

Then, to review

Take leverage, don't give it. Keep the toolrest close. Tools don't break
unless you're careless.

Energy still equals mass times velocity squared, so keep your speed low. A
good edge doesn't care how fast it's pushed - or pushed against.

A - Anchor the tool on the rest. If you have your off hand over the tool,
you'll never pinch a finger, no matter which toolrest you use, and you'll
avoid bounces that can steal your leverage.

B - Bevel on the work, heel first. When roughing the outside of a bowl,
place it center bottom - the point of least kinetic energy - to start. Work
out as you establish an uninterrupted surface to reference the bevel. Don't
RIDE the bevel, GUIDE the bevel.

C - Cut the wood as it wishes to be cut - across the fibers. Rotate the
tool to obtain as continuous a shaving as possible. You want to sever the
shaving as the edge exits. This is much easier to do with broader gouges,
though people who grind back the edge of their bowl gouges can get close to
the same by dropping the handle severely and cutting on the edge. They give
away a good anchor, however, which often leads to a catch, and lose one
intrinsic safety feature of a flatter fingernail-ground gouge, which curves
away from the cut in two dimensions instead of one.

Your shavings are as important an indicator as tool resistance of how well
you're doing.

"Lobby Dosser" wrote in message
news:BtLad.884$MY.677@trnddc03...
Greg G. wrote:

It's a small Jet
mini-lathe, so the probability of serious injury should be somewhat
reduced.


Greg,

The degree of injury is related to the speed of the lathe and the mass of
the object thrown, not the size of the lathe. IIRC, the Jet mini has a
speed range of about 500-3000, so you are working in the same speed
range as much larger lathes. The prime difference between the mini and
larger lathes is the size of object that can be turned. But, a 4-6 ounce
chunk of wood flying off a mini running at 3000rpm has the same injury
potential as the same size chunk flying off a larger lathe at the same
speed.

Someone once said that the difference between a table saw and a lathe is
the lathe can kill you. I've got an old face shield I keep as a reminder
of the dangers of turning. It has a nice gouge from a 4 ounce or so chunk
of bowl right about where the edge of my scalp would have been had I not
been wearing it and even with the protection, the impact was enough to
make me dizzy - like getting hit with a bullet while wearing a
bulletproof vest.

I don't want to rattle you, but you need to be as concerned about safety
on your mini as you would on a larger lathe. The safety habits you build
now will last you forever.

Have fun, but have fun safely!

LD



  #23   Report Post  
Greg G.
 
Posts: n/a
Default

Lobby Dosser said:

Greg G. wrote:

It's a small Jet
mini-lathe, so the probability of serious injury should be somewhat
reduced.


Greg,

The degree of injury is related to the speed of the lathe and the mass of
the object thrown, not the size of the lathe. IIRC, the Jet mini has a
speed range of about 500-3000, so you are working in the same speed
range as much larger lathes. The prime difference between the mini and
larger lathes is the size of object that can be turned. But, a 4-6 ounce
chunk of wood flying off a mini running at 3000rpm has the same injury
potential as the same size chunk flying off a larger lathe at the same
speed.


Actually, the injury potential would be related to the speed of the
lathe, the weight of the broken piece, and it's distance from the
centerline. ;-)

I understand what you are saying, however my point was that due to the
smaller diameter of things you can FIT over the bed, the risk is
reduced. The kinetic energy contained in a broken bowl edge, for
instance, is far less for a smaller diameter than a larger one. I
didn't mean to imply that there was NO danger, only that turning a 5"
vessel at 500RPM is far less dangerous than a 12" bowl at 1000RPM.

I ran a piece at higher speeds just to see what it was like. I didn't
even put a tool to it. It was just too fast for comfort. I cannot
imagine why you would use anything other than the two bottom speeds on
the Jet - at least for things over 1" in diameter. Having also worked
in the mechanical/automotive world, I have a great respect for things
that spin at high RPM - and what can happen when things go awry.

I used to build 10,000 RPM Rotary engines as well as more conventional
automotive engines. A flywheel disintegrating at even 4000 RPM is a
frightening and possibly deadly experience.

Someone once said that the difference between a table saw and a lathe is
the lathe can kill you. I've got an old face shield I keep as a reminder
of the dangers of turning. It has a nice gouge from a 4 ounce or so chunk
of bowl right about where the edge of my scalp would have been had I not
been wearing it and even with the protection, the impact was enough to
make me dizzy - like getting hit with a bullet while wearing a
bulletproof vest.


Now don't go and say that... I have a shop full of scary sharp
motorized tools, and occasionally someone posts a picture of some
bloody, severed appendage. It gives me the willys everytime I look at
that WoodWorker II sticking out of the tablesaw spinning at 4000 RPM.

Stories of carbides tips flying off blades and oak boards sticking out
of concrete block walls. Gee - maybe I should go back to collecting
Lepidoptera and assembling 1000 pc. puzzles. :-\

But I try to be careful, and never work when tired. I've been
fortunate to have avoided major injury in my life, and have done more
personal damage with a freshly sharpened chisel than anything else.
Here's to keeping it that way!

I don't want to rattle you, but you need to be as concerned about safety
on your mini as you would on a larger lathe. The safety habits you build
now will last you forever.


I hear you!

Thanks, Oh Slippery One!


Greg G.
  #24   Report Post  
Greg G.
 
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George said:

Greg, since you will be limited to cutting over the bed, you might be
interested in the information at:
http://personalpages.tds.net/~upgeorge/index.html


I've read most of your site the other day. There is so much
information to absorb, I'm sure I'll reference it, and many others,
again and again.

Never put yourself in the throw zone. You can cut as well if not better
from outside.


I try, but when roughing or trueing/shaping the outside of a blank,
difficult to do. Much easier to accomplish when working the inside.

Then, to review

Take leverage, don't give it. Keep the toolrest close. Tools don't break
unless you're careless.


Haven't broken anything *yet*. I don't force the tools, and do keep
the rest as close as possible.

Energy still equals mass times velocity squared, so keep your speed low. A
good edge doesn't care how fast it's pushed - or pushed against.


I'm still trying to figure out what the 3900 RPM speed is for. I'll
probably never use anything but the lowest two speeds. I wish they
had included a couple of even lower speeds! Maybe 100 and 250.
Roughing a bark covered, uneven blank at even 500 is pushing it, in my
opinion. I try to clean up a lot of it on the bandsaw, but it's still
unnerving to have an 8", unbalanced piece spinning at 500RPM.

A - Anchor the tool on the rest. If you have your off hand over the tool,
you'll never pinch a finger, no matter which toolrest you use, and you'll
avoid bounces that can steal your leverage.


Done - I value my fingers and eyes more than any other body parts.
It's how a make a living...

B - Bevel on the work, heel first. When roughing the outside of a bowl,
place it center bottom - the point of least kinetic energy - to start. Work
out as you establish an uninterrupted surface to reference the bevel. Don't
RIDE the bevel, GUIDE the bevel.


I have been using the bevel to limit the amount of penetration into
the cut. Although when I began, I used the bevel heel first method, I
soon learned that I could approach the piece directly with the proper
angle. Of course this changes with different tools and everytime you
move the rest - forcing you have to adapt, but I think I'm getting the
hang of it.

C - Cut the wood as it wishes to be cut - across the fibers. Rotate the
tool to obtain as continuous a shaving as possible. You want to sever the
shaving as the edge exits. This is much easier to do with broader gouges,
though people who grind back the edge of their bowl gouges can get close to
the same by dropping the handle severely and cutting on the edge. They give
away a good anchor, however, which often leads to a catch, and lose one
intrinsic safety feature of a flatter fingernail-ground gouge, which curves
away from the cut in two dimensions instead of one.


This is a technique I am still working on. And I still need better,
more appropriate tools before continuing with other box and bowl
projects.

Your shavings are as important an indicator as tool resistance of how well
you're doing.


This is quite true, as I've gradually noticed

Thanks Again, George!


Greg G.
  #25   Report Post  
John Weeks
 
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On Sun, 10 Oct 2004 18:04:41 -0400, Greg G. wrote:


Anyway, in the process of roughing out the interior of the container,
I discovered that it is not advisable to use a standard roughing
gouge. It seems to grab quite forcefully and gives the general
impression of being quite dangerous. I ended up using a parting tool
to do most of the excavation. I don't have a curled bowl rest, as no
one in the area seems to carry one for a Mini-lathe with 5/8" posts.
The container is only 2 1/4" deep, so I placed the straight rest as
close as I could, but it was still an eerie handful.


I've seen some people in this thread dancing around the issue but no
one I've read has come right out and said it:

Under NO circumstances should you use a roughing gouge against end
grain, as in bowl turning. Roughing gouges are designed for one thing
and one thing only - spindle turning. Some did mention they'd a friend
who had snapped a roughing gouge off at the tang using it against end
grain - that is exactly the danger.

Roughing gouges have relatively small diameter tangs in relation the
diameter of the cutting end. In spindle turning only a small part of
the gouge is actually cutting at any one time, and that is at right
angles (more or less) to the grain, so there is little chance of it
grabbing. The nice thing about all that edge on a roughing gouge is
that when the bit of the bevel you are using gets a little dull, you
can rotate it and use a different part of the bevel without having to
stop to sharpen.

If follows that there is no justification for modifying the profile of
a roughing gouge.


  #26   Report Post  
Ken Moon
 
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Greg G. wrote in message
...

SNIP ..........
I stay clear of the "throw
zone" - hard NOT to do when clearing interiors. It's a small Jet
mini-lathe, so the probability of serious injury should be somewhat
reduced. SNIP .........

.................................................. .......................

This line of thought can get you a quick trip to the hospital!! The
Mini/Midi lathes have a smaller capacity than some of the larger lathes, but
the danger comes more from the speed than the overall size of the work
piece. The Minis (most) have a minimum speed above 500 RPM. this can cause
some serious problems if you have an unbalanced or off center piece mounted.
At a minimum 500 RPM, a 10 inch long by 8 inch diameter hardwood log can
become a deadly missle in the event of a catastropic catch or separation ot
the piece due to internal faults. The tool can act as a lever to "throw" the
piece out of the centers and into suborbital flight. There are many in this
group who can tell you of damaged shop ceilings and or roofs from flying
work pieces small enough to be worked on "mini" sized lathes. Don't equate
small size with safety. Don't under estimate the energy (damage
capabilities) of a smaller piece of wood at high speeds.

Ken Moon
Webberville, TX


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