Hello everybody, don’t know how this could happen, but it
happened… My rolling mills cylinders are no longer parallel
(the mill is a “Durston” sheet and wire mill from GB if anybody
is familiar to this). Okay, I have an idea how it happened: I
wanted to roll through something really wide and therefore
turned the center wheel and turned and turned and turned… until
the two cogwheels which grab into the center wheel slipped out of
their guidings. Now I have no idea how to get the cylinders
parallel again. Please help!
Realigning the rolls shouldn’t be a problem. If the mill is
constructed as I suspect, the center gear meshes with the 2 side
gears, turing them the both at the same time. The center gear on
most mills can be lifted up so it’s teeth no longer mesh with
those of the 2 small gears on either side.
To realign the rolls, lift the center gear so it’s teeth no
longer mesh with the 2 side gears. On many mills the center gear
can be lifted until it is totally removed from the mill. If it
can be removed remove it. If it can only be lifted far enough to
disengage the teeth from the side gears, lift it as far as
possible & block it in this position by putting something between
the bottom of the large gear & the top of the mill. If it doesn’t
lift up, there may be a snap ring or pin through the shaft it’s
mounted on. The snap ring or pin will be located under the top
frame member. Remove the snap ring or pin to allow the center
gear to be lifted or removed.
When the gears are disengaged, turn the 2 small side gears, by
hand, until the top roll contacts the bottom roll evenly on both
the left & right sides. When turning the 2 side gears by hand,
try to keep the upper roll roughly parallel to the bottom roll.
If one of the side gears is turned quite a bit more than the
other, one side of the roll will lower more than the other. This
may result in causing the roll bearings to bind in the side
frame, making it difficult to turn the gears or if it’s far
enough out of parallel could damage the bearings.
When both the right & left sides of the top roll contact the
bottom roll evenly, reinstall the center gear. One or the other
of the side gears may have to be turned slightly (less than 1
tooth) to allow the teeth on all 3 gears to mesh. If your center
gear has index marks & numbers on it, align the ‘0’ index mark
up with the index pointer before meshing all 3 gears. If the
index does not line up exactly with the ‘0’ index mark, adjust
the index to align with the mark. The index is usually held on by
a screw. Loosen the screw and adjust the index, when the index
is in the correct position, tighten the screw.
If the center was held in with a snap ring or pin it can be
replaced now. It may not be necessary to replace the snap ring or
pin however. Gravity will serve to keep the center gear in place.
There is a disadvantage to leaving the snap ring or pin out, if
the center gear is inadvertently lifted out of mesh with the
side gears & 1 of the side gears turns, even a single tooth, the
entire procedure will have to be done again to put the top roll
back in the correct position.
Sabine, My rolling mill has a turning cog at the top (looks
like a bathroom tap but much larger) which indicates the
reduction size of each pass . I simply lift this out and hand
adjust either the left or right hand cog ,until the rollers sit
flush with no light shinning through.
Cheers
Marjorie Lord
Australia
42 degrees Celsius expecting 45 on XMAS DAY!!
Sabine: Peter Rowe gave me a tip on how to do this and it really
works well. I used an automotive feeler gauge but you can use
just any piece of flat sheet metal, probably thinner is
better.Turn each gear down or use the big adjuster to get the
rolls down until the piece of metal just barely grabs between the
rolls when you slide it around. Adjust each gear on both sides
until the metal piece slides equally all away across the rolls
with the same amount of friction, then when you got it right put
the big adjusting center piece back in to mesh with the gears.
One way to tell if its really right on is when you douse the
rolls with oil for when you’re not using the mill, tighten the
rolls down until they almost just touch and turn the crank. You
can see the oil spread EVENLY over the rolls as you turn. Adjust
the bite looser or tighter and you’ll see the pattern in the oil.
If there is more oil on one side then the adjustment is probably
a bit off. Hope this makes sense…Dave