Re: all-thread question

If you are putting together a test machine withnot stringent
requirements, but rather to just see how it all oges together, all
thread is fine.

the problem with allthread is that it is not designed to move but
rather lock in place. The angles of the thread and nut are designed
to move along as with any thread, but when the pressure increases,
much of the force is directed into the thread. ACME screws do not
suffer this same problem.

Now if you have ever tightened a 1/2 bolt you know there is a lot of
force to be had, so you will see a reduction in power directed into
the part if you use all thread. IF you are doing light loads, as in
light wood routing, PC board etching and such, you will find that
many people have been very successful with all thread.

Once you get into heavy metal removal, all thread goes out and ACME
is used. above that, ball screws. Increasing available torgue,
increasing accuracy, increasing money.

btw, search for all thread on this list, there is a lot of great
information here. especally what grade of thread to use (7-8) and
where to get it (McMaster)

Even a very eloquent and more technical rendition of what I stated
above.
Dave

--- In CAD_CAM_EDM_DRO@y..., "starcast82" <rh@g...> wrote:
> I'm going to start building my first cnc table and I'm trying to do
> it cheaply to start out. It is more a learning process at this
point
> and figuring out how to get it all to work and how hard it is to go
> from AutoCad to the CNC. After I get to that point I figure I can
> upgrade to better parts. After looking up the prices on Ball screws
I
> am planning on using all-thread attached to a stepper motor for the
> motion control. Will this be an acceptable and usable alternative
or
> am I wasting my time ? Thanks for the help.