Cost of linear actuators

Yes, people commonly (even normally) build linear actuators from
things like threaded rod.  Here is one source for the components.
www.mcmaster.com  Search for the phrase "Acme Threaded Rods".  They
have an extraordinarily well done web site.  There is a link on the
right to show the actual catalog page, which is easier to view when
you are looking to find the cheapest product.  Also if you search for
"linear actuator" you can get to a catalog page with a list of various
types of linear actuators.

However, if you are not used to specifiying the components for
something like this, it might be better to find a complete package.

Also, here is a link to a web site www.cnczone.com that has a forum on
a do-it-yourself cnc router (mostly gantry types).
http://www.cnczone.com/forums/forumdisplay.php?fH

Joe Dunfee

components.www.mcmaster.com Search for the phrase "Acme Threaded Rods".  They

types).http://www.cnczone.com/forums/forumdisplay.php?fH

Thanks for reminding me of McMaster-Carr.  I am looking at some
possibilities there.  They are my heros anyway.  Best website and
service on the planet for buying parts of all kinds!!

I would like to be a little more specific about what I am trying to
do.  I understand that I could design the components myself.
Ultimately I expect to be building low production quantities of these
and was hoping that a linear actuator/controller combination might
exist in the marketplace so I don't have to redesign the wheel.  I
have designed high-speed line printers and automotive sensors in my
career, so I could build one of these.  However, I don't want to find
(as I have in the past) that a simple, low cost solution exists that I
could use out-of-the-box and that is already being built in production
quantities.  Ideally, I would like to have 3 linear actuators, 2 of
which would be on an X-Y base and the 3rd that would travel vertically
from this X-Y base (call this the Z axis).  I would need to control
the three with a controller that would be programmed from a computer
program I would write for the specific application I have in mind.  (I
can't divulge the purpose of this device at this time in case there
are patent issues).  I need to be able to represent the position on a
computer screen and be able to return to that position (by storing the
X-Y-Z coordinates).

I don't think you are going to do it in your price range.  Here is a
commercial unit which I think represents the closest you are going to
get to your goals. It set a new price point when it was introduced.

www.shopbottools.com


Joe Dunfee

You have precisely described a common three-axis CNC mill or router. Do
a Google search and you should find a lot of commercial and homebrew
examples you can learn from.

-- Gordon

You can easily make what you described yourself with what you
described. I do it just about every day. With a little experimenting
you can too.

Hey castvee8, got any links we take a look at with examples ?
I'm always interested in good ways to do that.
Thanks !
JCD
http://www.AmazingRobotics.com  

You will find your solution at www.technoautomation.com

<snip>

You've gotten some pretty good responses so far, but you should take
note of something: the three foot travel is going to either cost you
money, accuracy, or both. Even at 0.050". Remember that to get a
*workable* 3 foot space you probably need a 4 foot (or so) linear
actuator. Ordinary low-end X-Y tables aren't designed for this size, and
the length causes all kinds of dimensional problems due to shear and
other stresses. You'll probably need to go to a roller-type gantry
system. Check out the X-Y table systems sold at robots.com for ideas.

Also keep in mind that if it's a cutting tool you're moving, and it
makes mechanical contact with the material it's cutting, you'll be
moving more than three pounds. You have to calculate bases on the load
on the tool. Obviously a laser, paint head, or water jet don't make
physical contact, but a router does.

I would definitely check out CNCzone.com so you don't end up reinventing
the CNC machine, at it were.

-- Gordon

I made an error in describing the space I need to traverse.  I only
need to cover a little over 12 inches on a side or about a 1 cu ft
space, not 3.  Maybe that will help.  The 3 lb load is all I have to
concern myself with.  I will not have an additional force to apply
except for a short, light cord that I will have to drag around which
should only amount to a few ounces.

That shouldn't be quite as expensive to implement, but as noted, there
are lots and lots and lots of CNC rigs and plans available on the Web. A
Google search will turn up how other people have done what you're trying
to do, which is a CNC router. There are already commercial products in
the $2K price point you mentioned earlier with specifications of the
type you mention, so take note of that if you're wanting to get into the
market.

-- Gordon