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Tony
10-06-2003, 04:18 PM
hello all.
here's a couple of pix of a little roll/ring bender i threw together. these run about $200-$300, and i've had my eye on one for quite some time. 6-7 hours in the shop, and maybe $20 in material (scrap) .. and here
it is.

someday i'll make the (apparently REQUIRED)... version 2 (how come everything needs to have versions?)

beefier this time, with BEARINGS.

this can handle light stock.. maybe up to 1/4" x 1" flats if you've had a good enough lunch to turn the handle.

http://www.photobucket.com/albums/0903/knucklehead/machineshop/bender1.jpg

http://www.photobucket.com/albums/0903/knucklehead/machineshop/bender2.jpg


-knucklehead

Dr. Rob
10-06-2003, 04:32 PM
Right on, Knucklehead! That's great stuff! I've been thinking of one of those for ages. Remember there was a thread on this a while back?

What you said about bearings...well, what does this have? Bushings? (And aren't bushings theoretically better for such a tremendous radial load?)

What about the thread, is that some gigantic trapezoidal thing?

And PS if I had found one of those for a measly 2-300 bucks, I'd have bought one long ago. I think you just saved yourself a bundle. And earned bragging rights.

Tony
10-06-2003, 04:38 PM
thanks Dr.B.
nope, no bearings, and no real bushings
to speak of. i just put the three mandrels through a reamed hole in 8mm plate.

so maybe the plate is a bushing? http://bbs.homeshopmachinist.net//smile.gif

no trapezoidal thread either. its a piece of M24 allthread i had laying around. plenty of squeezing power, though.

the rollers are interchangeable... though i haven't made a second set yet. would like to make some with round/square profiles for doing different cross sections.

going to knurl the rolls too, as you have to give the bar a push every now and again because of slippage.

-tony

JCHannum
10-06-2003, 07:17 PM
Nice job. Give us some help here, diameter of rolls, thickness of plate for instance. Most of us could extrapolate the rest, or adapt to our available material.

Tony
10-06-2003, 07:39 PM
i could throw some simple drawings together if you (or anyone) would like.

all of the materials i used were scrap/onhand.. so there's plenty of wiggle room.

the plate is 8mm .. ~ 200mm X 200mm
both pieces, front and back, are identical.

the rollers are 40mm diam and 50mm long.
if i'd make another set, i'd turn a 60mm down to 50 and leave a small shoulder toward the back, to keep stock from running into the body. maybe even on the front, to keep it from tracking out (sort of like a string bobbin/spool)

the pins are all 20mm rounds, apparently strong enough (so far) from what i've tried to bend.

plates are 50mm apart so that gives you about (8 + 50 + 8 + 50 =) 116 mm long pins.

the business end of the pins are bored/tapped for a bolt/washer to hold the roll onto the pin.

the top screw allows the center (drive) roll to move up and down (controls radius of curvature).. the pin for this roller is longer.. it sticks out the back so i could attach a handle to it. oh, and this is the only roll thats keyed to the shaft. so it turns when you turn the pin.

basically, screw the middle roll down onto your workpiece, and turn the handle till the turning gets easy. then screw down some more. repeat till you have desired curvature.

this thing, as i accidentally discovered, also rolls spirals. other than whirlygigs, i'm not sure what they'd be good for. but they sure look neat.

-tony

rangerod
10-06-2003, 07:54 PM
knucklehead

Nice job, I have been wanting to manufacture one of these rollers for a while. Do you have any drawings done up already? If you do I would like to see if I could get a copy, if not I'll work it out from what you already have given, Thanks. BTW did you or would you consider heat treating the rollers, would there be any benefit or would it make things worse?

[This message has been edited by rangerod (edited 10-06-2003).]

Ozarks Hermit
10-06-2003, 08:43 PM
Knucklehead:

Your timing could not have been better. This is Exactly what I just "have to" build, and soon! Any additional info would be great.
What I need to do is form some 1/8" thick by 2 to 3" wide steel into rims, from 6 to 12 inch dia.

Ken aka Ozarks Hermit
Shell Knob, Mo

Techtchr
10-06-2003, 09:05 PM
Knuckle head,
Very Nice, I need one, a picture is worth a thousand words, no drawing needed. Thanks! Nice Job
Matt

alcova
10-06-2003, 09:33 PM
I see your rolling pipe or tubing in one of the pics, doesn't it want to crush that tubing?

Walt

wierdscience
10-06-2003, 10:35 PM
Neat,been building one going on six years now http://bbs.homeshopmachinist.net//biggrin.gif

Thrud
10-07-2003, 12:42 AM
Nice.

Paul Gauthier
10-07-2003, 09:25 AM
I like it.

------------------
Paul G.

DR
10-07-2003, 11:16 AM
Guys,

Seems everyone wants one of these.

Another way to make a quick and dirty one is to use a milling machine vise, Kurt style or clone. Make big jaws, tap the top surface of the jaws for shoulder bolts. The shoulder bolts act as axles for the rollers.

Drive the single roll with a crank using forked spanner pins in the roll.

Can't say this is an original idea. Years ago a company sold this type roller, but used a bench vise instead of the milling vise.

Not quite as elegant as Knuck's design since there's no easy way to power the single roll.

Tony
10-07-2003, 01:40 PM
greets again, all.
thanks for the positive feedback.

some comments--

rangerod: heattreating.. possibly. depends on how often and how precise (as in, "repeatable") the bending would need to be. i would harden only after knurling.

i have seen the drive roll made of bronze and or plastic/rubber. so it seems slippage is a good potential threat.

OzardsH: what're you making, wagonwheels?? sounds like some tough bending work. the "beefier" version of this bending machine moves all the rollers BETWEEN the plates. instead of hanging them out the side, as i did.

another option would be the addition of a small bottle jack on top, to help with the bending. sort of like a press. in fact, exactly like a press http://bbs.homeshopmachinist.net//smile.gif

the real cherry-on-top would be a small motor / gearbox combo with direction reversing foot control.

alcova: you're correct.. after enough bending these cylindrical rollers would cause the tubing to buckle. in fact, the tube in the picture developed a small 'flat' on the inner diameter. i didnt bend anymore, so i'm not sure how tight it would go before buckling.. that little tube tired me out fast.

----
i'm working on a hand bender (die bender type).. i've made one or two already but they keep breaking on me. this one should close the case. trickiest part is figuring out which rollers to make, and in what size, to accomplish the most bending. i'm afraid i'm going to end up with a shop full of mismatched bending dies that i'll never use.

i can post pictures in a few days, perhaps, if anyone is interested.

enjoy,
& keep your fingers outta the rollers,
-knuckleH

MikeH
10-07-2003, 01:45 PM
You mention it tiring you out, you know, if you could make the crank longer, it will take less effort to roll the stock. Just a thought. http://bbs.homeshopmachinist.net//smile.gif

Ian B
10-08-2003, 03:34 PM
DR,

Nice idea on adding pins sticking out of the top of jaws on a milling vice to make a bender. Rather than turning one roller by hand, why not drive it using the spindle of the mill on lowest speed?

Ian

bikenut
10-08-2003, 04:20 PM
Nice Job! Got my brain cells (whats left) fired up. Been meaning to build a bender for my motorcycle frames. I think I will use hydraulic power instead of a screw though. Smitty

Mike Burdick
10-09-2003, 02:58 AM
Knucklehead,

Nice job! Here's a suggestion that might make constructing one a little easier.

Instead of making a handle for clamping down the pressure roller and the one for the powering the roller, just weld a large nut on the ends. This way you can use a ratchet or break-over bar. Get one made by Sears so if you break it - just take it back for another. http://bbs.homeshopmachinist.net//wink.gif

Mike

[This message has been edited by Mike Burdick (edited 10-09-2003).]

ibewgypsie
10-09-2003, 08:13 AM
Not really a clone, but I am building one of these type benders this week, the base? My english wheel frame with 2 inch reciever. I want mine powered.. just don't know how yet.

Smitty..

Get in your wallet and buy the model 3 bender. It does not deform or crush tubing. I got the degree wheel, and am using my indexer to set the secondary angles. It works great. Perfect bends. Some of the members here found them much cheaper then I paid for mine thou. Pictures of the frame jig I built to locate motor mounts too.

It has paid for it'self several times now. I have drawings -angles-inclination of frames too. About $1400 in investment. The cnc, lathe, and plasma, welders are used too. So I guess it is a lot more then that. Bending shoe I am using has a 4.5 inch center line radius.

I have changed servers, but pictures were at www.alltel.net/~decofer (http://www.alltel.net/~decofer) of the two together. I have not moved it yet to my new ISP.


[This message has been edited by ibewgypsie (edited 10-09-2003).]

Peter S
10-16-2003, 09:06 PM
Here is a link to a "ring roll" I just came across.

http://www.metalsmith.org/pub/mtlsmith/V20.3/roller.htm

I found it here

http://groups.yahoo.com/group/plansandblueprints/

ibewgypsie
10-16-2003, 10:36 PM
Thanks Knucklehead, You got me motivated again.

Mine has 18 inch wide rollers, actually more of a slip roll then a bender like yours.

The harbor freight model was made for 20 guage metal. I put the 11 ga sheet into it and the rollers promptly bent... Not a happy camper..

So, with your prompting, I am building one that will do what I want..