CNC Wire Bender (or Former)

So I'm fairly interested in attempting to build my own CNC wire bender (or former, as they also seem to be called). I've done some basic web searches and found some places that sell big industrial machines for this. I don't need or want a big industrial machine. I just want a simple bender, and it appears that building one is the only way.

That said, I'm really interested to see how the existing ones do what they do, yet I don't know anyone close by with one. Web searches seem to turn up some fuzzy pictures from far away of big machines, but that's it. Anyone know where I might find some pictures of one in action? Or even a bigger tube bender would probably be fine since it's the same concept on a larger scale (and obviously with added considerations like kinking).

I've got a basic idea, but I would just like to see one. Specs on what I want are something that can bend up to 3/16" diameter mild steel wire (which is really getting to the point of being small diameter rod, I think, but that's just semantics, right?). I probably don't care to bend at a radius any smaller than two or three inches, but being able to go up to fairly large radii is important (but that direction seems easier to achieve up to a point). I'll probably build a 2D machine (ie. it bends the wire in two directions, but any resulting output would lay flat on a table) to start, but would ultimately like to create one that can bend in 3D.

Any pointers at all on existing things to look at would be welcome.

--Donnie

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Donnie Barnes
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Shawn

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Shawn

bender..........

I have watched a few at shows. Wow ! Really neat and Fast !

The one I saw was along the lines of this....

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It didn't have the overhead unit shown there.

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.

You might see things better with this one,

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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.

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 !

Grummy

Reply to
grumtac

Sort of. That bender only bends in one direction, though. Note the use of three rollers. What I was thinking of would have four rollers so it could bend in one direction and then move back to straight and to the other direction. But still useful to see!

--Donnie

Reply to
Donnie Barnes

Already found that site...I wish they had some better pictures or videos, though.

This helps, believe me.

Well, one thing I didn't think about was straightening first. Hmm.

Thanks.

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

Reply to
Donnie Barnes

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

Reply to
Koz

I don't need high precision for the parts I'm building, though.

I gotta think I could.

Ah, I *only* need the push form type. I don't need hard angles.

Well, maybe more about what I'm after would help. Played any pinball machines with wire form metal ramps? Most are clear plastic, but some are what the pinball folks call "habitrails". They're usually four pieces of wire bent in parallel that the ball can move on. Many are straight, but many are also curved. I'd like to be able to reproduce some of the existing ones out there, but my real project idea involves "toy" machines that use similar curved "tracks" for pinballs to roll on and do cool things. This kind of thing can be done one-off by hand, but isn't very reproduceable that way.

Right.

I think the cutter would be pretty easy. The fourth axis wouldn't be bad, but I don't *need* it, either. Not something I want to work into the first design, anyway.

--Donnie

Reply to
Donnie Barnes

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