Straighening rollers

[Valentin]

Well my problem is like this ... i have a lot of stock that after texturing is bent in many directions ...some is square pipe other are flat bar ...round ...all kinds of steel ... are there any kinds of rollers or something to straight them up ? any ideas of how can i do them ?

[djhammerd]

Ries Niemi, an artist blacksmith that lives on the West coast, just posted on another form that he uses a Hossfeld bender to un-bend that which you describe.

[mike-hr]

For square and flatbar, I use this tool found at a yard sale. It's made from a large roller bearing with a round shaft welded off center to the inside bearing surface. A flat bar is welded to the outside surface. When the lever is pulled, it creates a cam motion. I can straighten 3/4 x 1-1/2 flat both ways with a 4 foot handle and a little effort. I've also used it to generate large curves for railings.
Motorized hydraulic presses work good, also.

[arftist]

If you are worried about damaging the textured finnish, use a wood block as an anvil, and a large wood mallet to straighten, even if hot. If not, use anvil and hammer. Find the low spot on the anvil,and strike over it. For radical bending, a hardy tool can be made; plate 1/2"x3"x6" long, with a 3" long rd. bar welded across each end, and a prong to fit hardy hole on underside. Place stock on rods and hit inbetween.

[Valentin]

Hmm i was thinking of something like this. What do u think will it work with square tubing ? I have many meters to straighen up and it takes more to do that than to texture .... i was thinking about motorizing 5 rollers and use something like that

Hmm i also found this design

[Valentin]

All your sugestions depend of the operatpr if he oresses the lever to mutch ...it bends if he hits to hard it bends .... i was thinking about something where u don't have to be to skilfull

[John B]

Hi Valentin, some suggestions.

Bonding machine, Jim Crow, flypress, or when you are texturing the bar straighten it as you go.

Bonding machines, are used to produce iron tyres for wooden wheels, (now known as ring rollers they can be purchased as a modern powered machine) they are a mini version of levelling rollers as used in steel mills for levelling/straightening bars as they come from the strip mills. Ideal for hollow sections as it is easily controlled pressure that should not collapse the tube as it may do if direct pressure is applied to a point.

Jim Crow (Don't know why they are called that, but no doubt someone on the site will) come in various sizes and were used for straightening bars up to railway line size. You could adapt this frame configuration and mount an eccentric roller on a lever where the screw is shown to reduce the time taken to apply the screw principle.

Fly press, one of the best versatile tools for the workshop, depending on how badly the bars are bent, two bits of curved top handrail section, one at each side, and another piece mounted on a top tool, should prevent the textured finishes getting marred. Just feed it through and press it level.

Finally, if you are texturing a bar, can't you just keep it straight as you are going along its length?

[arftist]

So I guess your question is whether or not you can build your own power staightener with 5 wheels. I don't see why not, provided you have access to machine tools, machinist skills, time to build it, money for all the parts and stock, and can justify the amount of time it will take. Do you need help designing the drive system? Bear in mind, you will need either adjustable dies or interchangable dies. As someone else mentioned, much straightening can be done during texturing.

[Valentin]

Very much thanks for your suggestion guys ...
The only problem is time into making the rollers but i hope i will find it as soon as posible seems that is the only way to straighen up hundreds of meters as fast as posible this are the rollers that I already made for arching different size of materials ... seems to be the same +2more rollers ... here is the pic of the ones i already did

[John B]

I would think that you could use your existing rollers as they are. I assume they are powered?

Just feed in your bar and put a gentle, regular curve in, then turn the bar the other way and adjust the rolls to neutralise the curve and it should come out relatively straight.

I have done this in the bonding machine shown and it works succesfully, however if the bar is twisted, then it becomes a little more difficult.

Two or more passes may be needed