a Ring Roller
First of all, what is a ring
is a device with 3 rollers. You roll a strip of metal between the
rollers, and it curves the metal:
My design works by using wrenches to turn the bolts. In practice,
it worked fine to turn only the bolt on the "middle" (rightmost) roller.
Why build one and not just buy one? Harbor freight sells a small
ring roller for about $50. It was too small for the jobs I wanted. The
next size up I could find was about $800. My ring
roller cost about $50 of materials. Also, the ring roller was a great
project for a beginner like me to practice my metal cutting, machining,
and welding skills.
Being a beginner, I bought a large steel plate and cut my
pieces from it. From this I learned it is much easier to buy metal as
close to the finish size as
you can! If I were to do another ring roller I would buy 1/4 inch by 6
inch wide pieces, and design it to use the 6 inch wide pieces. Also, I
am a beginning welder, so don't assume I mean for the pictured welds to
be Space Shuttle quality!
The main plates:
Left Picture: The long middle slot allows the center roller to move up
and down. The two holes below it are for the side axles. The bottom 2
holes were just to affix the plate to the mill to machine the slot and
holes. 2 of these plates were made.
Middle picture: Another side plate. The half circles in the ends allow
the ring roller to be bolted to a table top. 2 of these plates were
Right picture: The bottom plate. The big hole in the bottom is for the
main bolt, and the half circles to allow the ring roller to be bolted
to a table top. 1 of these plates were made.
These plates were welded together into a box:
I added a box structure to the bottom for strength. I figured if I was
going to bend 1/4 inch thick steel, I needed something stronger than a
1/4 inch thick plate on the bottom. The last picture shows how the bolt
goes. Turning the main bolt more will bend the metal more.
The next job was to make a structure that would hold the middle roller,
and allow it to be pulled down with alot of force by the main bolt. The
pieces were 1/4 by 1.5 inch mild steel. I made a box structure for
greater strength, and to keep the main nut from spinning. The holes are
for the axle bolts of the middle roller. I found that the arc on my TIG
welder would go sideways into the corners, so I gave up on welding the
beads all the way to the inside corners. Safety warning: Many nuts have
a coating that can be toxic if welded, so I ground off the coating
before welding the nut.
Here is the assembled product. I found it easier to just C-clamp it to
the work bench rather than bolt it down. The rollers are 1.5 inch cold
rolled steel. I drilled and tapped 1/2 inch holes in each end. A
smaller piece of bolt at the bottom of each hole keeps the 1/2 inch
bolt from bottoming and adjusts how far it goes in. The bolts just spin
in the plain metal. I greased the bolts, and it works great without
I had to remake the rollers. The first time I used a small lathe. It
was not strong enough, and flexed enough that the rollers spun off
center. I remade them on a friend's larger lathe, and they now work
To use it, just insert the piece of metal, tighten the main bolt a bit
(I've been doing about 1/4 turn at a time), and spin the rollers via
their bolts. Generally you'd do a curve with several passes. The
picture below shows it curving 1/4 x 3 inch steel. To my pleasant
surprise, it does not take much strength to bend metal this thick.
of a ring roller is the last inch or so of the metal does not get bent
and stays flat. You have to either live with that, or cut the flat
part off. Here is an example of a hoop I rolled. If you look closely,
you can see the last inch is still flat.
Advantages of my design:
- No structure above the middle roller allows for tight rolls
- It can roll up to 6 inch wide pieces of metal
- It works!
- You have to unbolt the middle roller to release a tightly
rolled piece of metal
- You need to grip the middle roller with vice grips to get
both bolts off