Texturing, piercing and carving/eroding are showing up on more and more
pieces - in woodturning magazines, web sites and demonstrations - as
turning trends more and more towards "post lathe enhancments" of
"mulit-media" pieces. Classic shapes and hollow forms seem to be running
out of "new" and really interesting woods suitable for these turned
objects are becoming harder and harder to lay your hands on - or VERY
expensive. The "segmented" area, and inlaying have an almost
inexhaustible area to grow in, but the time, skill and effort involved
preclude them as possibilities for many turners.

It's the time, effort and skill things that keep many turners from
exploring "post lathe enhancements". Who has the time - or patience -
to learn to carve or inlay really well?

As new tools become available, or tools from other disciplines are
"discovered", some turners will begin experimenting with them, looking
for ways to adapt them to their turnings - wood burning/scorching,
dental burs, die grinder burs - chainsaws (scaled WAY down of course),
new turnable materials, etc.. Their initial efforts are often quite
primitive, more investigations than fully developed integral components
of a turned then "enhanced" work. Initial reactions to these early
explorations are often - well let's just say - unfavorable.

I've recently been introduced to a new tool that has great potential for
"post lathe enhancment" of turnings - a laser engraver / cutter. This
new tool can "print" images on wood, engrave into wood, pierce through
wood - and shape wood, albeit within a limited range - AND any
combinations of these abilities. The possibilities are almost endless -
constrained mainly by the "depth of focus" of the laser beam and the
curvature of the turning - and of course, the imagination of the user.

I posted this url earlier to several turning forums - inlcluding this
one. Have added some about this 3-D "carving" ssince the earlier post.

http://www.svwoodturners.org/PieceOf...dexingJig.html

Not surprising, some saw the tool as merely a way to burn "clip art" or
a baby picture into a picture on a piece of wood - BFD! Others saw it
as "cheating" - no skill or artistry required - offensive to their sense
of aesthetics - overlooking the significant reduction in often risky
grunt work. (Ever spent a few hours cleaning out the "background field"
of a carving?)

But let's take some of the works of a turner many are familiar with -
Andi Wolfe. She's doing some beautiful leaf and botanical motiffs on
her turnings - minimal carving, color providing depth and tone. Now
imagine one her pieces with actual low relief carving, maybe including
veins in the leaf in addition to the stems major veins - and THEN she
adds the fall colors. She's drawing the leaves anyway - so why not
"draw" them on a layer of an image of her turning and have the laser
"print" her drawing on her turning? Save the hand carving time for
coloring!

Wonder how woodturners with a tendency for exploring will be using
lasers in the next few years - when Ginkos and Copy Centers make them
available to those that lack "deep pockets"?

charlie b

On Mon, 17 Mar 2008 11:43:17 -0800, charlieb wrote:


Wonder how woodturners with a tendency for exploring will be using
lasers in the next few years - when Ginkos and Copy Centers make them
available to those that lack "deep pockets"?

charlie b

As a better way to keep the cats away from the lathe?


mac

Please remove splinters before emailing

mac davis wrote:

As a better way to keep the cats away from the lathe?

I don't think a cat would like getting lasered this way.
But one of those laser pointers sure are fun when there's
a cat around - or some kinds of dogs : )

today, laser equipment with which I am familiar would have great difficulty
with anything much beyond a basic cylindrical shape - certainly doing Andi
Wolfe style motifs would require significant setup and some pretty advanced
math to calculate the inverse projections from the object's surface to the
laser control axis - my recommendation - don't give up your wood burning pen
just yet



--
Posted via a free Usenet account from http://www.teranews.com

On Mar 17, 10:52 pm, "William Noble" wrote:
today, laser equipment with which I am familiar would have great difficulty
with anything much beyond a basic cylindrical shape - certainly doing Andi
Wolfe style motifs would require significant setup and some pretty advanced
math to calculate the inverse projections from the object's surface to the
laser control axis - my recommendation - don't give up your wood burning pen
just yet

That seems to be the same opinion of my laser guy where I used get my
wood pens engraved. He started doing humidor lids, plaques, mementos,
etc., a few years ago. He had quite an investment into his system,
something like 30K. But he still couldn't do anything that required
more than simple 2D images.

Now he is looking at shutting down his business as the EPA licenses,
classes and certifications will be taking a great deal of profits.
And the city is going to require him to upgrade his exhaust system as
well. All in all, I don't think he wants to put another 50K in his
business and I think he will simply close.

Robert

William Noble wrote:

today, laser equipment with which I am familiar would have great difficulty
with anything much beyond a basic cylindrical shape - certainly doing Andi

I was thinking the same thing - but overlooked a couple of things the
laser engraving machines makers didn't. The effective depth of focus
on the laser I saw is about 1/8". Beyond that the laser begins to do
what laser folks call "blooming", the beam beginning to spread out,
losing it's effective "crispness". But when the beam is only 0.007"
in diameter, and it blooms 10% - it's still only 0.008" in diameter.

Let me try and put that in perspective.

The finest wood burning tools, the ones with the razor blade thin
tips can, in the hands of someone who knows how to use it, burn
100 lines per inch. I've got a book by a guy named Curtis J. Badger
who is a master bird carver. He uses a pyrography for bird feather
detailing. He does down (sp?) feathers that, from closeup photos,
would require actually touching to realize that they are wood. And
this guy can only do 100 lines per inch with the finest tips he
can find.

So - the surface area on a curved piece you can laser with
adequate crispness IS limited by the laser's effective depth
of focus and a function of the amount of curvature in the
area to be "engraved". I worked out the "effective width"
for 2 to 8" diameter curves and did the illustration near
the bottom of this page (I posted the url earlier and have
since added to it)

http://www.svwoodturners.org/PieceOf...dexingJig.html

So for an 8" diameter sphere, you'd have a circle about 1 7/8"
in diameter to "engrave" in - IF - you set the focus at the
high point. BUT - if you set the focus at the edge of the
the "effective depth of focus" you could double the diameter.
Of course that would mean that the "crispness" at the center
and edges of the "engraving" wouldn't be as crisp as possible,
but it probably wouldn't be noticeable to the naked eye, especially
once you've added color.

Wolfe style motifs would require significant setup and some pretty advanced
math to calculate the inverse projections from the object's surface to the
laser control axis - my recommendation - don't give up your wood burning pen
just yet

Laser engraving wouldn't work with some of her curved bowls
- on the inside. Could work on the OUTSIDE though
But for her shallower ones, and her plates and platters, those
are within the abilities of laser engraver


advanced math and calculations

Actually, the "printer driver" that the laser engraver company
provides
with the laser does a lot of the complex math for you. Computer are
really good at manipulating numbers and digital image files are just
numeric data. So if that "printer driver" tells the laser to not fire
when a pixel is "white", to fire at maximum power when it's "black"
(pierce) and dynamically change the power and frequency of the laser
pulse based on other pixels' "grayness" (carve, with depth defined by
"gray" numeric value), the computer and software tells the laser
what to do and where to do it - and it does it.

The laser's getting instructions on
WHERE to fire (x,y location)
HOW MUCH to use fire (power)
HOW LONG to keep firing at that spot (frequency)
HOW FAST to move to the next firing location

You get to set these "print" parameters, much like
selecting "fast draft", "normal" or "best" with an
inkjet or "laser" printer.

Now the cool thing about using a gray scale image
to act as a plan view contour map for a 3-D shape
is that there's software packages out there already
that let you create virtual 3-D objects fairly
easily - and then convert them into gray scale
"flat" image files. There was such a software
program called Bryce 3-D that was pretty powerful
and fairly easy to use - but - because of the
computational speed of computers at the time
could take hours to render a 3-D object when
you wanted photo realism.

This low relief 3-D "carving" using the laser has
some really interesting possibilities. See the bottom
illustration of a "basket weave" on the url
I gave above.

I've since been playing with gray scale texturing
using PhotoShop and some of the texturing filter
plug ins for it look like they could make the texturing
currently being done with flex shaft and burs and
carving tools all look pretty primitive by comparison.
Imagine doing scales or fur or clusters of tiny convex
hemispheres in areas of a piece.

Right now all the stuff I've done about using the
laser for engraving, carving and piercing are on
our turning club site. I think I'll start doing some
pages on it on my woodworking site. Will post the
url here when I've got something to share.

On Mar 18, 2:25 pm, charlieb wrote:

SNIP

I think this will fall into the "depends on who is doing it"
category. I will always have deeper appreciation for something hand
carved or rendered over machine carved.

I was over at my friend Lewis' shop when he was finishing up a carved
scene for the front of the podium of a small church. It was gorgeous,
and he had been working on it for a while (3-4 months) to get it where
he wanted it. It was lovely.

But I don't think a Compucarve would turn out the same thing. More
detail, yes. Sharper cuts, yes. The nuances that show it was hand
carved on wood, I guess you could program it. But it wouldn't be the
same. Work hard on the design, finish it up and save it. Then
putting in the board, turning on the machine and going to lunch
doesn't really seem like carving to me.

Maybe "the craft" in the case of the Compucarve or a laser engraver is
the design of the applied rendering rather than the finished product
which allows others to enjoy the computer design work.

I know the laser and its related machinery and software can do much
finer work than can ever be performed by hand, but I think that the
decorations will become so ornate and complicated that they too will
become just run of the mill.

But then again, you can only turn so much stuff round. We used to
have a turner in our little club that decided that turning a vessel
was no different than a painter making up a canvas and frame. that
was his start point. He happily burned, pierced, cut, veined, stained
and anything else his heart desired when he started operating on his
forms.

Right now all the stuff I've done about using the
laser for engraving, carving and piercing are on
our turning club site. I think I'll start doing some
pages on it on my woodworking site. Will post the
url here when I've got something to share.

As always, I'm looking forward to it!

Robert

In my youth I worked summers laying #3 sheeting. I had a Disston handsaw
to cut and a Plumb hammer to nail the #3 SYP sheeting to 2X8 rafters.
Down through the years handsaws were replaced by Skilsaws, hammers with
pneumatic nailers, the twisted & knotty
lumber with plywood CDX and the rafters with 2X4 trusses. As each of
these 'advancements' happened many carpenters deplored the predicted
loss of craftsmanship, losing jobs and wasting years of apprenticeship
due to those damn machines. The increased efficiency and likely better
product didn't bring on the present housing problems and caring
craftsmen like Robert are still around and likely using handsaws and
planes.

So What? Seems to me that in any art or craft there is a sine wave of
changes from simple (pure) to complex (mongrel) to simple again, etc.
The oscillations in style, decoration, fabrication, medium and tools in
furniture, architecture. painting and music are obvious.

I imagine that woodturning will follow similar curves and will probably
come full circle some day, although maybe not all the way back to pole
lathes, wooden trenchers and soup bowls, but who knows? Lots of
previous owners of kevlar canoes are making strip canoes, so it might be
birch bark and dugouts in the years to come.

OK, my tediously stretched out point is that to me laser engraving is
just another point along the sine wave, a computer numerical controlled
cutting system used for decoration instead of fabrication. Lasers for
woodturners are not to be praised or deplored any more than electronic
speed control or revolving tailstock spindles. If lasers advance the
craft/art or are just a novel addition, I'm all for it, but save your
buffers, chatter tools and wood burners boys, the well turned, nicely
finished hand embellished wooden bowl is "gone rise again".


Turn to Safety, Arch
Fortiter


http://community.webtv.net/almcc/MacsMusings

On Mar 18, 10:12 pm, (Arch) wrote:

As each of
these 'advancements' happened many carpenters deplored the predicted
loss of craftsmanship, losing jobs and wasting years of apprenticeship
due to those damn machines.

Absolutely true. When I started swinging a hammer, we laughed at the
weenies that needed nail guns to drive nails. There weren't many
nailguns out there, and the old ones weighed a ton and cost as much.
It was easy to make fun.

Plus, all of us had gone through the "learn how to drive a nail
camp". Since I was not deemed better for anything other than hauling
wood and sweeping, my next step up was a cloth bag with 8d nails in it
to nail off decking. Vast, open plains of decking on apartments. I
learned how to drive nails alright, but I couldn't open and close my
hands without pain for months. I thought everyone should go through
that if they were going to call themselves a carpenter.

NO ONE does that now. Hammers are not tools anymore, they are beating
and adjusting devices.
And so it goes. Looking back, I remember what disdain I had for those
that couldn't drive a few hundred 16d nails in a day. Now I don't
know anyone that can (including me!) and it really doesn't matter.

I imagine that woodturning will follow similar curves and will probably
come full circle some day, although maybe not all the way back to pole
lathes, wooden trenchers and soup bowls, but who knows?

I think you are exactly right on that. What's the old saying? "What
was once old is new once more" or something like that.

Some wild haired, bearded youth just out of college will feel "an
organic urge" when turning wood and he will turn a simple bowl. He
will feel connected to the elders of turning. He will be inspired by
the ancients. He will meet one or more of the grand old guard of the
craft that never owned a laser or a bag or prisma color dye markers,
and he will feel a kinship to the purity of the craft lost generations
ago.

Whatever.

It has to work this way; how else could it? If it didn't, the craft
would be lost.

Look at furniture making. From the old days in Europe, simple,
functional furniture was the design for homes. All the very best
wound up in castles, estates, etc. Then furniture and craftsmen come
to the USA, and there are craftsmen that can afford to make nice
furniture for homes because they can keep all the money for
themselves.

The incredibly ornate, highly stylized and tedious style of the
Federalist, Sheraton, Windsor, etc. were all here.
That lasted for some time.

Then Stickley.came along and brought his version of the British Arts
and Crafts movement. Ouch. After looking at a fine Federalist
buffet, looking at a Stickey piece was like looking at a middle school
child's shop project. Simple woods, simple designs, simple finishes,
straight cuts, exposed joints... it's all there. It went away, for a
few decades, but it is back now. Simple, difficult, simple,
difficult; it is no more than a swing of the pendulum.

OK, my tediously stretched out point is that to me laser engraving is
just another point along the sine wave, a computer numerical controlled
cutting system used for decoration instead of fabrication. Lasers for
woodturners are not to be praised or deplored any more than electronic
speed control or revolving tailstock spindles. If lasers advance the
craft/art or are just a novel addition, I'm all for it, but save your
buffers, chatter tools and wood burners boys, the well turned, nicely
finished hand embellished wooden bowl is "gone rise again".

I couldn't agree more. I think the computer driven stuff is neat, but
it will lose its appeal. Someone will come along and "rediscover"
the simple beauty of a turned bowl and a clear, uncolored finish.
They will praise the shape, ask about inspiration, and it will all
start again.

That's my take, anyway.

Good post, Arch.

Robert

" wrote:

Simple, difficult, simple,
difficult; it is no more than a swing of the pendulum.


How about unadorned and adorned. 'Simple' is quite often more 'Difficult'
to design and execute.

"charlieb" wrote in message
...
William Noble wrote:

today, laser equipment with which I am familiar would have great
difficulty
with anything much beyond a basic cylindrical shape - certainly doing
Andi

big snip

I think charlie (and others) that you missed my point - it has NOTHING to do
with focus, it has to do with the projection of the desired shape onto an
unknown geometric surface and the resultant distortions - I am unaware of
laser drivers that can be programmed with a highly nonlinear surface, and I
am unaware of laser etching equipment that includes a interferrometer or
other equipment to measure the surface prior to etching so that the
requisite image warping can be precalculated.




--
Posted via a free Usenet account from http://www.teranews.com

On Mar 20, 12:45 am, "William Noble" wrote:

I saw a great show on 3D carving on of non linear surfaces where he
laser rotated around the object and cut/burned exact depths to create
round shapes for casting molds, part representation molds as well as
making one off objects for various tests.

It was similar to this where he operator scanned a 3D image of a model
and then let the laser carve the model as a duplicate in 3D, wrapping
or warping around the CAD file to correct dimension and feeding it
into the laser.

http://www.cyberfx.com/3d_laser_scanning.htm

The intriguing part to me was that the laser in the documentary made
the decision on how much power was fed to the laser while cutting.
Don't know if the above laser was this sophisticated.

I think charlie (and others) that you missed my point - it has NOTHING to do
with focus, it has to do with the projection of the desired shape onto an
unknown geometric surface and the resultant distortions - I am unaware of
laser drivers that can be programmed with a highly nonlinear surface, and I
am unaware of laser etching equipment that includes a interferrometer or
other equipment to measure the surface prior to etching so that the
requisite image warping can be precalculated.

The science documentary I saw used the laser interferrometer (had to
look that one up!) to measure a human skull with a clay face that was
made for a "prehistoric man" exhibit. The didn't want the skull in
the exhibit, so they fashioned a face onto the skull, put it in the
laser chamber's hold, and measured the skull with the face on it. The
idea was that the clay would come off after the face was recorded and
the skull would be cleaned an safely stored.

The laser took something like two to three hours to scan the head in
3D. Then the image was rendered into a format the cutting laser
understood. This took something like another 12 hours or so. After
it was finished, they cut the head the next day out of foam in perfect
3D and the representation of the real skull with clay face was almost
perfect.

That head would seem an easy task compared to the woman/model above.

Interesting topic.

Robert

On Wed, 19 Mar 2008 23:45:38 -0700, William Noble wrote:

"charlieb" wrote in message
...
William Noble wrote:

today, laser equipment with which I am familiar would have great
difficulty
with anything much beyond a basic cylindrical shape - certainly doing
Andi

big snip

I think charlie (and others) that you missed my point - it has NOTHING
to do with focus, it has to do with the projection of the desired shape
onto an unknown geometric surface and the resultant distortions - I am
unaware of laser drivers that can be programmed with a highly nonlinear
surface, and I am unaware of laser etching equipment that includes a
interferrometer or other equipment to measure the surface prior to
etching so that the requisite image warping can be precalculated.

Measuring the surface prior to etching is easy, depth is still difficult
if not impossible to consistently control. There are a number of ways to
handle the focal point, usually laser scanning based, or old school piezo
based. Some of the laser cutters have a 3D scanning attachment. You mount
the workpiece, scan in it's dimensions and map that to your model to
verify positioning before you start cutting. Or just scan in and sculpt
in your 3D app, then post your model to the cutter.

Many 3D shapes can be made with 4 or 5 axis linear tooling.
"Non-linear" diamond tooling is made using lasers.
http://www.bls-laser.com/shape.htm
Lasers are used to cut gemstones and diamonds.

You are correct that only a few home-user $20,000 lasers have variable
focus yet. Laser and waterjet cutters can do some amazing constrained 3D
work using 4 or 5 axis CNC indexing. Many cheap laser engravers also do a
"cheater" 2.5d engraving using laser power adjustment to control the
depth of the cut. The 3D laser crystal engravers use variable focal depth
and are getting cheaper every day.

I shopped out getting my wood stock inventory cut by waterjet and laser.
I found more than a few shops than can do it, but it was not yet cost
effective for me. Waterjet seemed to be a better fit for the type of
cutting I need or at least more waterjet shops were cutting wood than
laser shops.(small laser shops were usually cutting metal) If I ever get
to ramp up production I would definitely consider laser or waterjet to
prep materials. Many marquetry shops use both machine and hand. Laser/
waterjet to cut repeated patterns which are hand inlayed into the backing
board along with hand cut pieces for natural variations desired. When
prep cutting thousands of the same geometric pieces you really want to
get to the installation part of the job. There's more going on than just
prep cutting to achieve the end result.

If someone really cares about not using technology they should be
planting seeds and growing their own trees and never be using any power
tools anywhere along the way.

On Mon, 17 Mar 2008 11:43:17 -0800, charlieb
wrote:

Snip

Wonder how woodturners with a tendency for exploring will be using
lasers in the next few years - when Ginkos and Copy Centers make them
available to those that lack "deep pockets"?

Funny you should mention this- I've been considering getting a laser
for just this purpose. So that those who haven't looked at this have
a bit of an idea, an Epilog 45 watt laser with a rotary attachment
(which would allow a guy to etch the outside of a turned piece) is
about $17,000 new.

Granted, this is expensive, and I agree that etching family portraits
and the like does not sound like much fun, but going off the car I
bought new a few years ago (at a high interest rate, lucky me) a guy
would have to earn about $400 a month for the tool to pay for itself.
It'd be awesome to do that with laser engraved bowls or something, but
I think the most realistic prospect is to etch family portraits on
some relatively inexpensive wood like pine or balsa, and try to sell 5
or 6 of them a month to make the payment.

Looking at it this way, I figure that, if I actually get one (which is
certainly not a decided thing yet) it'll be a matter of taking on a
fairly easy part-time job in exchange for having a really cool toy to
play with on my own projects. Hell, if I could impoverish myself for
a reliable vehicle that is no kind of sensible investment at all, I
figure something like this is a much wiser move.

As far as using the thing goes, it would seem to be simplicity itself-
the unit hooks to a PC with a networking cable, and works like a
regular printer. It needs Corel or CAD to cut parts from wood, but
will evidently engrave from any program that can make use of a
printer, so as far as I can see, the sky is pretty much the limit.
With a handful of good filters, a guy can make just about any image in
photoshop in an hour or two.

On Mon, 17 Mar 2008 21:52:43 -0700, "William Noble"
wrote:


today, laser equipment with which I am familiar would have great difficulty
with anything much beyond a basic cylindrical shape - certainly doing Andi
Wolfe style motifs would require significant setup and some pretty advanced
math to calculate the inverse projections from the object's surface to the
laser control axis - my recommendation - don't give up your wood burning pen
just yet.

You raise a vaild concern here- but there's a lot to be said for
designing the piece to fit the machine. While it might not work very
well to etch a full-face scene on a spherical object, that doesn't
stop a guy from applying some nice banding on some strategically
turned planes.

Sure would be nice if the things used standard g-codes, though- while
it might make for big programs, being able to control the z-hieght to
etch contours would be excellent.

On Fri, 21 Mar 2008 03:19:35 -0000, Joe wrote:

I shopped out getting my wood stock inventory cut by waterjet and laser.
I found more than a few shops than can do it, but it was not yet cost
effective for me. Waterjet seemed to be a better fit for the type of
cutting I need or at least more waterjet shops were cutting wood than
laser shops.(small laser shops were usually cutting metal) If I ever get
to ramp up production I would definitely consider laser or waterjet to
prep materials. Many marquetry shops use both machine and hand. Laser/
waterjet to cut repeated patterns which are hand inlayed into the backing
board along with hand cut pieces for natural variations desired. When
prep cutting thousands of the same geometric pieces you really want to
get to the installation part of the job. There's more going on than just
prep cutting to achieve the end result.

If you're looking to get into it yourself, I'd suggest waterjet-
provided it won't mess up your wood. While I'm fairly comfortable
with the idea of etching wood with the laser, cutting parts is another
matter. The actual cutting is fine, especially if done with nitrogen
as an assist gas- but the problem is in dust collection.

Without a dust collector, cutting wood with the laser smokes a lot.
With a collector that is strong enough to be effective, there's a good
chance that it will suck the smaller bits into it. I wouldn't have
thought that that was much of an issue *until* I had the misfortune of
having the dust collector at work catching fire on me. It wasn't
mine, or anyone else's fault- but it was a horrendous mess and a lot
of thick smoke to deal with. And, we cut metal- not wood. If a laser
cutter can set aluminum and steel dust on fire to make a little
impromptu thermite 20 yards from the actual cutting area, I would
imagine that a collector full of charcoal and bits of wood would be
even more likely to go up in smoke.

If someone really cares about not using technology they should be
planting seeds and growing their own trees and never be using any power
tools anywhere along the way.