How can I bend flat bar into a circle?
Dante M. Catoni
weld it together. I tried making the circle of plywood and then bending it
around with a lever pivoting on the center. It starts out OK, but I can't
get the end to come together correctly. I also have one of those compact
metal benders from Harbour Freight which I've had much less luck with. I
have to make 40 of these. I want them for the centerpieces I am making for
my wedding reception, similar to this
http://www.angelfire.com/ri2/rktpwr/centerpiece.jpg
Thanks to Doobie and Leo Lichtman for the tips on making the spiral legs. I
made a fixture of wood and pipe that makes it a very quick process.
Thanks
Dante Catoni
Charles S
main spring.
(This put the shakles bolt holes on the top and ended up lowering the rear).
With chalk, they drew the curve they wanted (the original curve) on a sheet
of steel.
They took a big block of steel that had a vee in it,
and 3 men did the job. One held a 'handled blunt chisel' (like a rounded
axe).
One had the sledge hammer, and the last one worked the spring.
They started on one end of the spring, and gently beat the chisel on the
spring over the vee in the big block.
Going from one end to the other, eventually, the spring was straight.
They kept this up and eventually the spring started to recurve.
Finally, when they would get to the other end, they would check the recurve
against the chald line.
They kept at this until the recurved the spring matched the chalk line.
Easier to take it to a foundry and have it rolled.
*******************************************
"Dante M. Catoni" <vze3...@verizon.net> wrote in message
news:XfkDc.4245$Av3....@nwrdny01.gnilink.net...
Ecnerwal
"Dante M. Catoni" <vze3...@verizon.net> wrote:
> I want to bend 12" long pieces of 1/8" X 1/2" mild steel into a circle and
> weld it together. I tried making the circle of plywood and then bending it
> around with a lever pivoting on the center. It starts out OK, but I can't
> get the end to come together correctly.
A ring roller - basically 3 wheels where one wheel can be squeezed down
between the other two, and one or all of them can be driven to run the
metal through - gradually increasing the offset until the desired circle
is acheived.
If you're going with a wooden form, try a form with holes that permit
you to use an absurd number of c-clamps to get the band clamped into
place for the weld. Wet the form before welding to keep the fire down.
--
Cats, Coffee, Chocolate...vices to live by
Leo Lichtman
"Ecnerwal" wrote A ring roller - basically 3 wheels where one wheel can be
squeezed down between the other two (clip)
^^^^^^^^^^^
A ring roller will work, but it will leave the ends of each piece straight.
Since you already have a HF "Hossfeld" type bender, I would use it to do the
ends, and then run each piece through a ring roller.
Since this only has to be eyeball perfect, you might try bending an
imperfect ring on the HF bender, welding the ends, and then going back to
the bender and truing it up. I think you will find that the bender will
sort of "talk to you" about what adjustments are needed. If the handle
moves too far, you will know that is a part that is bent too much. So keep
tweaking the parts that are not bent enough.
wallster
"Dante M. Catoni" <vze3...@verizon.net> wrote in message
news:XfkDc.4245$Av3....@nwrdny01.gnilink.net...
around to the other end welding the two ends together, then grind the tack
on the pipe.
good luck,
walt
Bert
solution, but ... if you have access to a bandsaw, cutting the rings
out of a piece of 3" or 4" schedule 40 pipe might be an easier way to
get what you want, assuming you have some leeway with the 12"
circumference. Or you could set up a jig and cut them out with a
cutting torch for a slightly textured edge. If you insist on rolling
the pieces, you know that the ends are the hardest parts to form
properly, so one approach is to roll two pieces slightly larger than a
semicircle, cut off the ends to form two semicircles, and then weld
them together.
Bert
Ernie Leimkuhler
<vze3...@verizon.net> wrote:
Always beend the ends first, using a hammer and something round or a
vise, then bend your rings.
You can buy a small simple ring roller for about $50 from Harbor
frieght.
Dave Mundt
There is more than one way to do this.
1) Buy a tool...get a circle roller, and simply run the metal
through it several times, until it ends up the "right" size.
2) Weld up a jig consisting of a couple of 3/4" rods, about 3"
long, to a thick base. Space them a bit apart...say...half an inch?
Use them as pivots to slowly work bends into the strip of metal until
it is the "right" shape.
In both cases, build a template to adjust it to the correct
size. It is always easier to spring a circle OUT a bit, and have it
still work ok, then it is to pull the ends IN to each other. Go
slightly over 360 degrees and then cut the ends to fit perfectly.
Regards.
Dave Mundt
Will Hunting
If you only need a few, then you dont want to waste a lot of time
making your tooling. Just wrap it around a pipe and hammer it a few
times.
If you are making thousands, then I'll tell you what "I" would do.
Make a small tube furnace out of ceramic fiber in the shape of a tube.
Both ends of the tube are open. You can feed your stock continuously,
and it comes out hot on the other side. As it's coming out, simply
wind it around a piece of pipe in the shape of a spring. Then, after
cooling, you make one long cut along the length of it and you'll have
buckets full of rings. Or, you could cut them oen by one with a bolt
cutter or whatever.
Judging from the picture you provided, it should be possible to do
this without heating at all. In your case you could also wrap the
steel into a spring shape and THEN heat top red hot and allow to cool.
Will
Carl Ijames
for a steel ring a little thicker than you want, or check the index for
others that may do :-).
--
Regards,
Carl Ijames carl.ijames at verizon.net
RoyJ
can't get it apart when done!!) Clamp a 10' piece of the 1/8"x1/2" bar
on to the post, start wrapping it around the post in a spiral. Remove,
make a cut to change the spiral to rings, push together and weld it up.
You may need to adjust the spiral to get exactly the diameter you need
but all the rings will be exactly the same. You can get a bit more
uniformity if you use a follower made of a 2x4 and some big bolts to
keep the bend point exactly at the surface of the form pipe.
Doobie
"Dante M. Catoni" <vze3...@verizon.net> wrote in message
news:XfkDc.4245$Av3....@nwrdny01.gnilink.net...
By looking at the picture the ring is only about 4 inches in diamater ...I
think the absolute easiest way would be to cut half inch long pieces of 4
inch tubing , then you have zero forming to do. If you insist on rolling
pieces, just roll them to a bigger diamater and cut the flat ends off and
weld it together.
Good Luck...glad I was able to help on the leg portion!
--
Doobie
04 XL1200C
02 XC500SP
Shaun
> > weld it together.
We make a lot of rings like this where I work and they are mostly used
for mounting booys onto grain silos; they have to be really round. We
have numerous benders of different designs, and the three wheel ones
are pretty good, but end up leaving the last part of the circle flat.
For a lot of them, we work out the *diameter* of the circle from the
radius, then make your flat about 300mm longer. Bend it with whatever
you have so you get a lot of overlap, then cut some of each end off so
that the diameter is right. Now you have the right size circle, it
just isnt perfectly round, but it a good start.
Weld them together, then find out which part of the circle is 'high'.
Don't cring. Now throw it at the ground so this part hits. Repeat as
necessary until you have a perfect circle. Use a jig to find when its
round and when its out.
You might laugh, but this is just about the best and easiest way of
getting a perfect circle. A lot of custom made rims are 'trued' in
this way too.
Shaun
Lucky Strike
pieces 1/2" long? Much quicker and cheaper too.
"Dante M. Catoni" <vze3...@verizon.net> wrote in message
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Gregk
I found this thread of this forum looking for ways to make my 3", 2" and 1"
flat bar into 32", 30", and 20" circles. I have access to a welder, but no
metal bender or torch. I do not want it to look hammered and I want perfect
circles.
The method of over-bending then welding and hammering it out cold, Is this a
good method for big circles as well, it seems like you would have to be super
gentle to not make it an oval each time. Thanks
--
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Ed Huntress
<0f8503901d844703ee...@example.com> wrote:
>replying to Shaun, Gregk wrote:
>I found this thread of this forum looking for ways to make my 3", 2" and 1"
>flat bar into 32", 30", and 20" circles. I have access to a welder, but no
>metal bender or torch. I do not want it to look hammered and I want perfect
>circles.
>
>The method of over-bending then welding and hammering it out cold, Is this a
>good method for big circles as well, it seems like you would have to be super
>gentle to not make it an oval each time. Thanks
but...
Making good, smooth circles out of bar like that, by hand, is
something about which I would be very skeptical. That's a job for a
Buffalo or other tube/pipe/section bender. Even that takes some skill:
http://www.nxtbook.com/nxtbooks/fabshopmagdirect/february2014/#/29
--
Ed Huntress
Bob Engelhardt
> replying to Shaun, Gregk wrote:
> circles. ...
OK ... there is no such thing as a perfect circle - there are only
circles with tolerances. You could have circles that vary by +- .5" in
diameter (pretty good), +-.25, .1 (Very good), .01 (exceptional), etc.
The welding/hammering is not going to work very well for a beginner. To
get anything reasonably close to a "perfect circle", you're going to
need something like this:
http://shopoutfitters.com/338-pedestal-ring-roller/
Of course, if you could elaborate on what you want to do, we could give
better answers.
Bob