I can't, even after paying for a private lesson for the thing, get
my stuff to "work properly" on the rolling mill. I end up with
crooked metal, faint imprints and lots of disappointment. No
matter what I try (tighten/sandwich between metal or paper/et), I
get the same results.
Lori, I didn’t see your original post(s), but one thing in this
latest stands out to me. You’re talking about roll printing. using
the mill to imprint and texture.
And that’s fine.
But understand that this use is not what rolling mills are primarily
designed to do. Their intended use is to make sheet metal, or with
groove rolls, wire, thinner, into thinner sheet or thinner wire
(usually prior to drawing the wire to final dimensions).
Here lies the first bit of advice. Make sure you can successfully
use the mill for it’s primary purpose. Is the mill capable of taking
a straight strip of metal sheet, and rolling it thinner without it
warping or bending to the side? If so, then at least you know the
roll is properly adjusted. If the metal bends to one side, then your
first task is to level the rolls, by tightening or loosening one of
the side adjustment screws, either raising or lowering one side of
the upper roll relative to the lower roll, to get them parallel.
You’ll never get even roll printing if the rolls don’t start flat and
even. Once this is done, you don’t need to touch that adjustment
again for a long time, as once leveled, the rolls pretty much stay
that way.
Then, in roll printing, whether you sandwich the metal between other
metal or texture objects or not, doesn’t in itself affect the metal
staying straight. What affects it is whether the total package of
metal, any sandwich, and the texture item is effectively thicker on
one side, or the middle. If so, and thus more metal is being
compressed and displaced in one place than another, then the result
will always be some form of deformation. This is normal. And it’s
not necessarily a bad thing. You may, if your desired imprint will
require this sort of uneven pressures, simply have to put up with the
distortion. The answer is to make the metal larger than the desired
end piece, so you can trim, and get the needed size piece from the
larger textured stock you produce, thus getting rid of the
distortion. Any warping is dealt with easily by annealing, then
using a rubber, plastic, leather, or other soft mallet to flatten the
metal on a flat steel surface or softer, like nylon or wood, if
you’re trying to keep a texture on both sides of the metal. The
mistake in such cases is simply in the expectation that the mill is
the only tool to use to obtain the perfect final piece. It’s not.
It’s just the main one. Then you work with the result, bent,
distorted, or whatever, to get what you need to end up with. In roll
printing, there will often be some waste material along sides or ends
to be trimmed off.
The more and thicker layers you sandwich the metal in, ie other
metal above or below the worked metal and the texture item, the
harder it will be to get a deep crisp impression, as more of the
rolling compression will take place in other than putting in the
desired impression. Your metal itself can contact the roll on it’s
underside if you’re not trying to emboss that side and can leave it
flat.
Any metal above your texture is there simply to prevent embossing a
texture on the roll itself (which is only partially hardened, and can
be textured/damaged if you’re not carefull). But softer things like
paper or lace, don’t need that protection, and may give a crisper
image without. The upper “sandwich” layer may, however, help hold
everything in position, and if it’s thin, and already fairly hard
metal (I like brass sheet. You can get fairly thin shim stock which
is already fairly hard, though soft enough to protect the roll) then
the deforming energy will stay in putting the texture into the work
piece. A thicker or softer sandwich layer will absorb more of the
compression energy, and result in a weaker impression on your work
piece.
Also, expect to have to run trials with small scraps of the work
metal and texture item, to find the proper settings to get the right
impression and resulting product. It’s not always intuitive or easy
to guess. Once you get the right result on your scrap, try tightening
the mill just a tiny bit (assuming your workpiece is wider than the
test scrap), and using that setting. If you have trouble with this,
you may need more than one trial to get it right. Again, don’t let
this frustrate you. It’s just the normal way this technique can
work.
Once you’re used to it, and making the same end product many times,
you’ll get a better feel for just how to achieve it without all the
trial and error.
Hope that helps
Peter Rowe