Donnie Barnes wrote:
On Mon, 21 Nov, wrote:
I have watched a few at shows. Wow ! Really neat and Fast !
The one I saw was along the lines of this....
http://www.opton.co.jp/new_hp/overseas/cnc_wf.html
But, It didn't have the overhead unit shown there.
Already found that site...I wish they had some better pictures or videos,
though.
I watched one bend a "Flower" out of 5/16 or 3/8. They had a roll
feeder behind the machine, and the wire came thru a feeder, and on the
end where it came out, there was a rotary head that could spin 359
degrees around the end. This head was not sophisticated really, it just
had a few pins of fingers that would grab and bend the material as it
came right out of the feeder. I wish I could explain it better.
This helps, believe me.
You might see things better with this one,
http://www.aim-inc-usa.com/AFM-3Dx-T.htm
Well, one thing I didn't think about was straightening first. Hmm.
Yea..that's going to be a big one. To do it right, you need a rotary
straightener which is either a big fab job or big bucks. you MIGHT be
able to get away with a simple roll straightener but repeatability will
be near zero.
Then you need a VERY strong drive for the pinch rolls to pull the rod
out of whatever straightener you use and (possibly) push it into the
former. Generally these rolls are carbide, about 6" diameter. Big
bucks. However, you could probably get away with heat treated steel for
the kind of production you will be doing.
Depending on the ultimate size of your parts, the arm with the forming
head may need to stick out of the machine quite a way. This arm needs
to be beefy for the wire you are planning on using. Even a little
deflection can really muck up the final results of a complex bend. Most
machines I have seen put a servo in the main frame of the unit and
connect the end of the forming arm via a "silent chain". This allows a
smaller profile at the end of the arm to interfere less with the formed
part.
To do it right, remember there are 2 different bend motions. One is a
simple bend where the wire is fed, stops, and the former makes an
angular bend to match the die set. The other action is a push form.
The wire is forced against the bending arm which may move as the push
happens to vary the radius. It takes a lot of pressure to do this and
the wire needs to be very well controlled (held on path down the arm to
the forming head). Also, wire varies a bit on hardness so spring back
might change from foot to foot of the material...fancier machines have
load cells in the straightening rolls and automatically compensate for this.
I would be a really fun toy but it's not the kind of thing you can just
scab together and get good, repeatable results.
2 axis wouldn't be bad to build yourself (although it would still be a
lot of work). 3 axis is where the money and really cool projects lie.
The third axis is probably the easiest of all to build and takes the
lightest servo so don't dismiss the idea.
You should also plan for an automatic cutter and a possible 4th forming
axis at the forming head to do helical bends. A little up push while
also doing standard push bending can open up a whole realm of other
possibilities.
Koz
That whole front head spins on that "Circle" in the front. The wire can
stay stationary other than being fed out whatever distance is necessary
to the next bend.
One thing was, these "Flowers" were about 3 foot tall when done, so
they had a bretty large fenced off area so no one could get "wrapped
up" in that rascal as it flew around. Every time it made a bend, the
growing "flower" flung around like a wild banshee. And again, it was
FAST.
If I find some time tomorrow, I will look around for a link to what I
watched operate.
Thanks.
Regarding building your own, entirely possible. In fact, your best bet
would be to check into the DIY-CNC or CAD_CAM_EDM_DRO Yahoo groups or
try CNCZone and throw your ideas out there. People have built
everything from EDM to WaterJet to Laser, so it sounds like a fun
project !
I bet a 3d version of the machine, could use basic 3 axis G code as
well..... This would be a fun project no doubt !
Yeah, I know about the groups. Should post there soon. I've already got
some of the hardware bits worked out, but it's a very small percentage.
Thanks for the info!
--Donnie