Beefy bender

[mklotz]

I have an excellent German bending jig kit capable of making very complicated bends in wire and strip steel. However, it's complicated to set up and a bit of overkill for smaller jobs so I decided to build something a bit smaller and simpler to handle the occasional bending requirement on models and for various forms of shop tooling.

The first photo shows the component parts. The main part is the large cylindrical "table" (my term - there's probably a correct name but I don't know it). The table has a central hole surrounded by a spiral of holes. These holes accept 1/4" steel pins which acts as restraints and formers when bending. The central pin is also used to anchor larger dies (not shown) when bending larger radii. These dies are usually made up as required by the job at hand.

A 1/2" steel plate (still covered in red layout die) fits over the table and, constrained by three screws, is free to rotate about the table. It has a slot through which the bending "tooth" (more personal terminology) is attached. The slot allows the tooth to be adjusted in and out relative to the table center. This tooth is clamped such that the material to be bent is forced against the former as the plate is turned.

A delightfully crude handle made of 3/4" gas pipe attaches to the plate to provide plenty of leverage when bending.

Here another view of the table shows the groove into which the dog-pointed screws that anchor the plate to the table fit. The screws are sized such that, when tightened down, the plate is still free to turn.

Also shown is one of two flats on the table which are used when clamping it in the vise. They're a bit meek and need to be made bigger but I haven't gotten around to it yet.

And, finally, a picture of all the bits assembled and the bender mounted in the bench vise. A sample of the work that can be done is the small hook made of coat-hanger wire shown lying on the plate.

This thing is grossly over-built. My education is in physics, not mechanical engineering, so "design" is guided more by what stock is currently available that "for sure" won't break in the intended application. I'd wax apologetic but I surmise that I'm not the only one here who does this.

Regardless, this brute works well and, though heavy, shows no sign of bending or breaking.

[Frank S]

Marv there are very few things wrong if you could call them wrong with over building a tool.
They are heavier than fully optimized designs, but they seldom fail due to potential weak areas.
They use more materials which can be more costly except when re-purposing scrap or parts on hand.
They have a tendency to last almost forever which means you only get to build them once
They often morph into tools which can transform into other tools that you would not even consider doing with a lessor tool.
Nope' I'll take an over built tool for personal use any time

[PJs]

Thank you Marv, perfect timing and another ask and receive for me. I'm with Frank, Beefy is fine for lots of reason. I have some 3/8" 01 to put some compound bends in 3 different pieces. Like the dogpoint swivel idea. Not sure I have the stock for this but I'll get creative. Thanks for the great idea!

BTW I got some rubber dip for my tweezers...works great. I'll probably be a dipping fool from now on. Thanks for the tip!

Regards,
~PJ

[DIYer]

Thanks mklotz! We've added your Bender to our Metalworking category,
as well as to your builder page: mklotz's Homemade Tools. Your receipt:

Bender by mklotz

tags: bender

[G.Paul]

Marv Looks nice and simple. How big of a diameter rod can you bend. I just bought steel this morning to build a bender was going to go with the HF style, you may have changed my mind.

[mklotz]

Marv Looks nice and simple. How big of a diameter rod can you bend. I just bought steel this morning to build a bender was going to go with the HF style, you may have changed my mind.

I really don't know what its (wire/sheet) upper limits are; I've never attempted to bend anything that it couldn't handle. When I do bigger stock I automatically go to the German kit mentioned in the post.

Just as a guess, I don't think I'd try anything bigger than 3/16" in steel, maybe a bit bigger in brass.

Its real advantage is its small size and simplistic setup.

[Okapi]

Hi mklotz,
Really a nice work, and very clean for the use, as a maker of a similar tool for silver or gold wire I use in reparation, can i suggest you an idea if you have to curve flat or round really little sized metal when you do to have a curve perfectly round from the beginning.
Just make a pin with an eccentric center for the center hole, fixed by screw or just holding with a key, then you can make a pressure on the first millimeter if you want and the metal cannot slip, this is especially usable for flat wire( I can hold 0,6mm. flat gold wire for example) to insert into an existing slit. ;-)
Have a nice day.
Pierre

[G.Paul]

Marv can you elaborate on the german bender i don't see it in your post

[Jeff Michel]

Excellent, thank you for sharing. How did you determine the hole position in the "table"?

[mklotz]

Excellent, thank you for sharing. How did you determine the hole position in the "table"?

The hole positions are calculated from the equation for an Archimedian spiral, r = a + b*theta. However, there's nothing sacred about their location. If you build your own you can place the holes according to your personal requirements.