Re: Metal Bender Question

Whew, lots of questions..

For tubing the rotary draw benders have the advantage of being able
to use an internal mandrel for support in bending thin wall. With a
rotary type all the bending takes place in the same location with
respect to the bender. The unbent end of the tube has to move as the
bending occurs.

With the "unknown" type the bending occurs as the material is rotated
around the center die. The unbent end will be stationary.

Other than the internal mandrel issues, I'm not sure of any big
advantage of one over the other. Both can do high precision,
repeatable bending.

The ram type benders are usually thought of for lesser precision
work. And might not be able to do as thin wall tube as the others.


Comparing the Diacro and Hossfeld...as you mention the Hossfeld's
have a larger material bending capacity than any of the Diacro's.
However, the Hossfeld is much more difficult to setup and much harder
to get repeatable bends. Comparing their instruction manuals, it
looks like both will do the same things, within their relative
capacities. Costwise, you could buy a couple Hossfeld's for the
price of one Diacro. I'd take the Diacro over the Hossfeld anyday!!

Doug


--- In CAD_CAM_EDM_DRO@egroups.com, STAN MCDONALD <SMCDONAL@K...>
wrote:

> Hello list.
>
> I am working on the design of a universal metal bender and would

like

> the input from the group.
>
> Benders are classified into three types
>
> <ram bender> works like a log splitter and used in muffler shops
> it's fast but it does require hydraulics and it does crimp the work

and

> leave tool marks.
>
> <rotary draw tube benders> works by clamping the work to the side

of the

> die and the die is rotated and a follower roller forms the metal

around

> the die as it is being turned.
> Supposed to be the best method and is used on CNC machines
>
> <unknown> Where the die is fixed in the center of the bender and the
> work is held next to the die by means of a pin and then a follower
> roller die is used to form the work onto the die held in the center

of

> the machine. J&L Industrial sell a hand bender like this for small
> work, however I want to make a large version that is more adaptable

to

> other operations.
>
> MY question What is the advantage of the unknown and the rotary draw
> type bender? Seems to me that since you are forming the metal

around the

> die by means of rotating the die or rolling the stock around a
> stationary die the result should be equal. We all realize that any

of

> the three methods shown here will work but what makes one better

then

> the next?
> I am only interested in manual hand operated benders at the moment.
>
> There are several types of benders out there.
> Diacro is a good one and then there is Hossfield and then the import
> copy of the hossfield. With the exception of the fact that the

hossfield

> and the copy of the hossfield will bend a larger diameter of a given
> stock size. Is there any other advantage of one VS the other?
>
> Does the hossfield bender have any advantages over the diacro

bender?

> Is there another bender that is better in certain respects to the

diacro

> or hossfield bender and if so why?
>
> If you where looking for a bender what would me the max circle dia

that

> you would want to bend material. What would be the max stock you

would

> like to bend (keeping in mind this is a hand bender).
>
> Thanks for your input.
> Regards
> Stan