Re:Which Counterweight System to use?
Posted by
Yahoo
on 2007-10-01 09:32:29 UTC
<snip>Has anyone out
describe it here because I'm too lazy to draw a picture, but I imagine those
who can think in 3D will get it. This puts it in the public domain, so
unless someone has already patented it, it can no longer be patented. Here
is how you do it:
First, the terms and mental frame of reference: Imagine you are standing at
the end of your gantry table. The "near right" corner is nearest you on the
right, the "far left" is farthest on your left. The "gantry" moves toward or
away from you. The "cross slide" moves left or right along the gantry. The
"head" moves up or down on the cross slide. You want a counter weight to
balance the weight of the head but not interfere with the operation of the
other moving parts or add weight to the gantry or head.
Attach a pulley to the top of the cross slide and connect a cable to the
head. The cable goes up from the head, over the pulley and down. The other
end of the cable attaches to a saddle which holds another pulley, now
dangling at the and of the first cable. Pulling down on the second pully
lifts the head.
Now here is the really clever part. Attach a cable to near right corner of
the table. Run it along the right edge of the table, over two pulleys on the
gantry that divert it up and then left. Run it over a pulley on the right
side of the cross slide diverting it up, over the pulley hanging on the
saddle from the head cable, back down to another pulley on the left side of
the cross slide, which diverts it to the left again. Now it runs over to
more pulleys on the left end of the gantry, diverting it down and away from
you, now running along the left side of the table. At the far left corner of
the table it runs over one last pulley that diverts it down, where it
terminates in a saddle with a weight equal to the weight of the head.
The gantry and cross slide can move freely along the length of the cable,
but the cable keeps a constant pressure on the head. That is, assuming all
your cable direction changes are 90 or 180 degrees. One of there days I
might actually do it myself.
--
Phil Mattison
http://www.ohmikron.com/
Motors::Drivers::Controllers::Software
> there done a counter weight on a moving gantry type router? </snip>I've thought a lot about this very problem, and I have the answer. I'll
describe it here because I'm too lazy to draw a picture, but I imagine those
who can think in 3D will get it. This puts it in the public domain, so
unless someone has already patented it, it can no longer be patented. Here
is how you do it:
First, the terms and mental frame of reference: Imagine you are standing at
the end of your gantry table. The "near right" corner is nearest you on the
right, the "far left" is farthest on your left. The "gantry" moves toward or
away from you. The "cross slide" moves left or right along the gantry. The
"head" moves up or down on the cross slide. You want a counter weight to
balance the weight of the head but not interfere with the operation of the
other moving parts or add weight to the gantry or head.
Attach a pulley to the top of the cross slide and connect a cable to the
head. The cable goes up from the head, over the pulley and down. The other
end of the cable attaches to a saddle which holds another pulley, now
dangling at the and of the first cable. Pulling down on the second pully
lifts the head.
Now here is the really clever part. Attach a cable to near right corner of
the table. Run it along the right edge of the table, over two pulleys on the
gantry that divert it up and then left. Run it over a pulley on the right
side of the cross slide diverting it up, over the pulley hanging on the
saddle from the head cable, back down to another pulley on the left side of
the cross slide, which diverts it to the left again. Now it runs over to
more pulleys on the left end of the gantry, diverting it down and away from
you, now running along the left side of the table. At the far left corner of
the table it runs over one last pulley that diverts it down, where it
terminates in a saddle with a weight equal to the weight of the head.
The gantry and cross slide can move freely along the length of the cable,
but the cable keeps a constant pressure on the head. That is, assuming all
your cable direction changes are 90 or 180 degrees. One of there days I
might actually do it myself.
--
Phil Mattison
http://www.ohmikron.com/
Motors::Drivers::Controllers::Software