Rolling Mill Problems aligning the rollers

The rollers on my mill must be slightly off. When I put a piece of
metal through of any good length (say a 7" strip of 18g sterling), it
curves on one end. I’ve removed the cover to the gears but don’t see
an obvious way of re-aligning the rollers. Can anyone help me?

Cathy Flory
JEWELWORKS
www.jewel-works.com

When the two rollers are not square (parallel to each other) You
will be making daggers as one side is lower than the other. To
remedy this you need to remove the T handle or the wheel that adjust
the opening and manually rotate the top two gears so both the top
rollers are parallel. Normally it is better to go down all the way
till they touch each other and can go no further. Replace the T
handle a slight readjustment may be needed to set the middle gear.

That should clear your problem.

Regards,
Kenneth Singh
karat46@aol.com

The rollers on my mill must be slightly off.  When I put a piece of
metal through of any good length (say a 7" strip of 18g sterling), it
curves on one end.

I’ve never met a rolling mill that doesn’t have adjustment knobs.
Most have two knobs at the top and to either side of the handle that
adjusts the rollers to thin or thick.

Get a feeler gauge from a hardware store or auto parts supplier to
help you determine the correct adjustment, as it will save lots of
trial and error. Insert the thickest gauge in between the two rollers
until it just catches on one side of the rollers or the other. On the
side that’s high, adjust the top knob in a counterclockwise motion
until the roller also touches the feeler gauge on that side. Then
tighten down the rollers to catch a feeler about half way in the set
of feeler gauges, and adjust the knobs again. Keep doing these two
steps until you’re down to the thinnest feeler.

Keep the feeler gauge. In the future, you may find a need to roll
wire to a wedge shape or to introduce a curve to sheet, and so you
would open up one side of the rollers higher. It’s also useful for
doing certain types of fold forming when in this position. But of
course you’ll want to be able to put it back to the level position
for most rolling.

I’ve found that going to the Automobile supply stores offers a
gadget called the “spark plug gap” tool. You can use this to make
sure that the gap between rollers is equal on both sides.
Inexpensive and readily available.

Hi Gang,

I've found that going to the Automobile supply stores offers a
gadget called the "spark plug gap" tool.  You can use this to make
sure that the gap between rollers is equal on both sides. 

Another tool that can be used that is much handier is a set of
‘feeler gauges’. This is a set of metal strips usually about 3/8"
(10mm) wide & 2 - 3" (50-75mm) long. The strips are different
thickness starting about .001" (.000039mm) & going up to about .035"
(.09mm). Thicknesses not represented by a single feeler can be
checked by stacking 2 or more gauges together. Feeler gauges are
usually under $10 depending on the quality & size.

They’re generally available at stores that sell tools used by
mechanics & machinists.

Dave

To check your rolling mill without wasting valuable metal, get two
straight pieces of clean unblemished copper wire. 12 gauge solid is
good. Cut the wires 4 in. long.

Set your mill for a substantial, though not excessive reduction .
Start both the wire strips at the same time, one on each side, close
to the outsides. Roll normally, do not back up. If the roll is in
alignment vertically, a good micrometer or calipers, should show both
wires reduced the same amount . Measure several times . Do not mix up
the wires The smallest difference is the most desirable and is the
closest to perfect alignment . We are looking for measurements in
1/000’s of an inch. Closer the better.

The rolls ( I have seen ) run in bronze bushings. These rollers need
to be subject to the same forces when testing as they would be when
being normally used . Keep adjusting the left and right geared
wheels. Keep checking and adjusting as needed. Copper wire is cheep
. MAKE NOTES, DRAW PICTURES IF NEEDED.

After you are finished, roll the metal and take turns rolling right
side up, and then up side down . Do not swap ends as I have heard this
can adversely affect the quality of the sheet.

This should equalize any curvature left .

ROBB