Twenty-five years ago I got very interested in concrete and polymer-matrix
machine tools, and studied the hell out of them for a while, but never did a
darned thing about it. I'm wondering if there is enough interest among
hobbyists to try to get a discussion group or something like that going.

There are a lot of routes that might be taken -- post-tensioned,
ferrocement, polymer-modified, fiber-reinforced, not to mention
polymer-matrix machines -- and there is room for a lot of experimentation on
such things as aligning spindles, embedding bedways, and so on. A lot of the
testing and experimenting can be done on the cheap. All it takes is time. I
don't have the time to do it all myself but I'd like to see something come
of it.

Is anyone interested? And for you guys who are more web-savvy than I am,
suggestions for a way to upload and display photos and drawings?

I'm just looking for a show of hands to see how many might be interested.

--
Ed Huntress

....
Is anyone interested? And for you guys who are more web-savvy than I am,
suggestions for a way to upload and display photos and drawings?

I'm just looking for a show of hands to see how many might be interested.

There's been a HUGE thread on this very suject on CNCzone.com. Several
thousand posts and a few actual machines built. I've only got a few
minutes till the Marathon Lady leaves the dock. I'll search for the
link tonight.

karl

"Karl Townsend" wrote in message
...
...
Is anyone interested? And for you guys who are more web-savvy than I am,
suggestions for a way to upload and display photos and drawings?

I'm just looking for a show of hands to see how many might be interested.

There's been a HUGE thread on this very suject on CNCzone.com. Several
thousand posts and a few actual machines built. I've only got a few
minutes till the Marathon Lady leaves the dock. I'll search for the
link tonight.

karl

Thanks, Karl. If it's already been well done, that just leaves us more time
for fishing. d8-)

--
Ed Huntress

Thanks, Karl. If it's already been well done, that just leaves us more time
for fishing. d8-)

Nine 'tails and two mangove today, kinda slow.

here's the link www.cnczone.com/forums/showthread.php?t=30155

I guess its about epoxy granite. There's an older one on concrete.

Karl

http://www.cnczone.com/forums/showthread.php?t=25283

www.cnczone.com/forums/showthread.php?t=27234

http://www.cnczone.com/forums/attach...9&d=1175483284

http://www.cnczone.com/forums/attach...5&d=1178030533


http://www.cnczone.com/forums/archiv...p/t-14480.html

I should add that like any newsgroup, there a lot of chaff to separate
from the wheat. This forum needs an idiot filter more than RCM

Karl

"Karl Townsend" wrote in message
...
http://www.cnczone.com/forums/showthread.php?t=25283

www.cnczone.com/forums/showthread.php?t=27234

http://www.cnczone.com/forums/attach...9&d=1175483284

http://www.cnczone.com/forums/attach...5&d=1178030533


http://www.cnczone.com/forums/archiv...p/t-14480.html


Thanks, Karl. It took some time to go through all of those, which is why I'm
slow getting back to you.

There are a few ideas in there but, frankly, those guys are mostly not up to
speed with this material. The machine designer who complained about cracks
in the polymer concrete reinforced it incorrectly. Most of the others are
talking about making sheet metal structures and trying to beef them up with
concrete. That's really not what I'm talking about. That's been done for
decades (particularly by the Italians and the French), and the structural
design issues they've had to face are much more complex than those posters
are talking about. That kind of structure, while it sounds simple, is
anything but.

I would have approached this as a long-term research project years ago,
except that I don't want to spend that much of my spare time, and I see no
money in it. No time, no money...I don't do those things anymore. g I'd
get involved now just for the hobbyist satisfaction of it IF there were at
least a dozen other people who were serious about it and who would
contribute. But I realize after reading those threads you linked to that
even guys who are knowledgeable machinists may not understand stressed
concrete and concrete composites enough to do serious things without a lot
of study. Some boatbuilders know ferrocement, and some architects know FC
plus post-tensioning. Civil engineers usually know general reinforcement and
prestressing. Now I need to find a few of those who also are amateur
machinists. d8-)

So, I'll put it back in the can for now. Maybe when I retire -- if I ever
retire. Thanks again for your effort; it kept me from reinventing a wheel.

--
Ed Huntress

"Karl Townsend" wrote in message
...

Thanks, Karl. If it's already been well done, that just leaves us more
time
for fishing. d8-)

Nine 'tails and two mangove today, kinda slow.

here's the link www.cnczone.com/forums/showthread.php?t=30155

Heck, I thought I'd get to see some pictures of fish. g I walked across a
nearby pond today, looking for bluegills frozen in the ice. I had my ice
axe, but no luck.


I guess its about epoxy granite. There's an older one on concrete.

I stopped in there and searched on "concrete"; 'found some comments, but
nothing substantial.

Anyway, it all depends on whether enough people really want to get into it.
There is plenty of information around to get one dabbling with the idea, but
I'm wondering if people want to dig a little deeper.

--
Ed Huntress

Sounds interesting Ed. A quick Google search turned up this:

http://books.google.ca/books?id=uG7aqgal65YC&pg=PA356&lpg=PA356&dq=concre te+machine+tools&source=web&ots=6-OdlmVa_H&sig=Sakj_5qwhHL5fH3KXLdpbUaYn1A&hl=en&sa= X&oi=book_result&resnum=4&ct=result

--
Pete Snell
Department of Physics
Royal Military College
Kingston, Ontario,
Canada
-----------------------------------------------------------------------
Being shot out of a cannon is always better than being
squeezed through a tube.

Hunter S. Thompson (1939 - 2005) Kingdom of Fear

"Pete Snell" wrote in message
...
Sounds interesting Ed. A quick Google search turned up this:

http://books.google.ca/books?id=uG7aqgal65YC&pg=PA356&lpg=PA356&dq=concre te+machine+tools&source=web&ots=6-OdlmVa_H&sig=Sakj_5qwhHL5fH3KXLdpbUaYn1A&hl=en&sa= X&oi=book_result&resnum=4&ct=result

--
Pete Snell
Department of Physics
Royal Military College
Kingston, Ontario,
Canada

Ha! That's interesting. The first reference on that page is to an article
written by one of my old co-editors at _American Machinist_, Joe
Jablonowski.

I've heard of that book and it's one I should get for my reference shelf --
as soon as I win the lottery g. Thanks, Pete.

--
Ed Huntress

On Jan 14, 11:36*am, "Ed Huntress" wrote:
Twenty-five years ago I got very interested in concrete and polymer-matrix
machine tools, ...
Is anyone interested? And for you guys who are more web-savvy than I am,
suggestions for a way to upload and display photos and drawings?
Ed Huntress

200 years ago lathe ways were made by mortaring iron strips into
granite blocks. The closest I've come was welding a framework from
steel channel and angle and shimming the pillow block bearings into
alignment. As a long-time prototype machine builder I prefer a design
and construction method that is easy to modify. Plastic castings don't
have much tensile strength, especially where material has to be added
and the reinforcing fibers don't cross the joint. Rapid prototyping
resins were the worst, I've needed to cut away a large bonding surface
and sculpt several batches of epoxy to build up a boss that would hold
a new bearing.

My Picasa photo links have remained on one line since I started
prefixing them with . I don't know how you could post drawings except
as graphic images, there isn't any common drawing package other than
MS Paint. I draw machine parts with a Mentor Graphics circuit board
layout program that theoretically writes and reads DXF, but I've been
unable to open one from another CAD program with it.

Jim Wilkins

"Jim Wilkins" wrote in message
...
On Jan 14, 11:36 am, "Ed Huntress" wrote:
Twenty-five years ago I got very interested in concrete and polymer-matrix
machine tools, ...
Is anyone interested? And for you guys who are more web-savvy than I am,
suggestions for a way to upload and display photos and drawings?
Ed Huntress

200 years ago lathe ways were made by mortaring iron strips into
granite blocks. The closest I've come was welding a framework from
steel channel and angle and shimming the pillow block bearings into
alignment. As a long-time prototype machine builder I prefer a design
and construction method that is easy to modify. Plastic castings don't
have much tensile strength, especially where material has to be added
and the reinforcing fibers don't cross the joint. Rapid prototyping
resins were the worst, I've needed to cut away a large bonding surface
and sculpt several batches of epoxy to build up a boss that would hold
a new bearing.

Right. The loads and their directions on standard machine tools, though, are
well-defined and they have been dealt with effectively in concrete and
polymer structures. Polymer is easier because it's ductile; reinforcing
fiber begins to take up the tensile loads as they're applied, without
destruction of the polymer.

Concrete is more difficult because it's brittle, as well as having almost no
tensile strength. For that we have prestressing, post-tensioning,
ferrocement, and modified concretes. They're still a challenge but there's a
ton of experience with and information about structures built that way, much
of which applies very nicely to basic machine tool structures. It's also
worked well with some boat structures -- although it has enough problems
that ferrocement boats have waned in popularity over the last few decades.

It's an intriguing idea. If others here who have more up-to-date exposure to
the developments in the field it would be good to hear from them.

--
Ed Huntress

In article ,
"Ed Huntress" wrote:

I'm just looking for a show of hands to see how many might be interested.

I'm interested. I have a CNC (woodworking) router which started life as
a kit cheap enough that I could buy it, but which therefore has more
flimsiness than I'd like - structurally similar to a (metalworking-type
elderly) planer, and it might be that if I could find a planer that
hadn't hit the junk bin, that would be the better starting point, but
flinging something together from scratch has some appeal, if it can be
done without breaking the bank, particularly considering that most
planers have probably already been sent to China and melted down...

OTOH, Anyone with a planer (or shaper, for that matter) to part with in
reach of SW Vermont, let's talk...

--
Cats, coffee, chocolate...vices to live by

"Ecnerwal" wrote in message
...
In article ,
"Ed Huntress" wrote:

I'm just looking for a show of hands to see how many might be interested.

I'm interested. I have a CNC (woodworking) router which started life as
a kit cheap enough that I could buy it, but which therefore has more
flimsiness than I'd like - structurally similar to a (metalworking-type
elderly) planer, and it might be that if I could find a planer that
hadn't hit the junk bin, that would be the better starting point, but
flinging something together from scratch has some appeal, if it can be
done without breaking the bank, particularly considering that most
planers have probably already been sent to China and melted down...

OTOH, Anyone with a planer (or shaper, for that matter) to part with in
reach of SW Vermont, let's talk...

--
Cats, coffee, chocolate...vices to live by

Ok, let's see what Karl comes up with from the CNC forum he mentioned. If
they've worked out the details, that's a good place to begin.

Depending on the quality and stiffness of the guideways and so on, you may
be able to reinforce the machine you have, possibly with concrete structure.
Once you work out a way to reinforce it, its properties are pretty good.
Ferrocement, for example, has about the same density, tensile strength, and
compression strength as aluminum, with much better vibration damping
properties.

--
Ed Huntress