Denis G. wrote:
On Dec 14, 5:15 pm, wolfgang wrote:

On Dec 13, 1:31 pm, KD7HB wrote:






On Dec 13, 9:33 am, "Lloyd E. Sponenburgh"

lloydspinsidemindspring.com wrote:

" fired this volley in news:cc5a1ba4-
:

I can not see well enough to tell, but I think the handle turns the
roller.

The hand crank turns an offset crank arm on the roller. The link pin
creates the offset, and carries the torque from the hand crank to the
crank arm. 'Tis a weak point of possible failure, methinks; but it
allows the mechanism to work, which it could not if the link were
attached directly to one side or the other of the hand crank. If the pin
is stout enough, it would be strong enough -- it just doesn't look very
big.

LLoyd

The top roller looks a lot like one of the commercial rollers I have
in my junk pile(shop!). The two powered rollers are of similar size,
but must be made by the operator. The rest appear to be welded up. I
wonder if I have enough junk to make one? Might be an interesting way
of recycling metal.

Anyone else see the old steam tractor in the background? Watch the
roller sequence and look at the back wall.

Paul

This bending roll arrangement as shown above is called 3-roll pyramid,
and is typically used to roll heavy plate for large pipe, pressure
vessels, and steam drums. Bar stock, as shown, can also be rolled.
For round rod a groove is helpful.

For it to function it is necessary that the work piece be stout enough
so as to carry a substantial force so as to drive the work piece
through the rolls via friction.

A former employer of mine had a German made machine that would roll 6"
thick plate into a 6' dia. cylinder cold. It would also break that
plate if it was too hard!

This type of bending roll arrangement is not suitable for sheet metal
work. For sheet metal the top roll and one bottom roll must be able
to securely pinch the sheet metal in order to drive it past the
bending roll, which is offset and is adjustable so as to determine the
work diameter to be rolled.

To recapitulate: For thick material only the top roll requires
adjustment for driving force and work diameter.

For sheet metal work the top roll is adjustable to pinch the sheet
metal against one of the bottom rolls, and the second bottom roll is
adjustable separately to determine the final work piece diameter.

There is a 4 roll pyramid arrangement to do thinnish plate work; top
and middle bottom roll to pinch the sheet, outside bottom rolls
adjustable to bend the sheet and determine work diameter.

Wolfgang- Hide quoted text -

- Show quoted text -


I'm not sure how the roll arrangement would be to bend a 6" thick
plate into a 6" ID cylinder cold. I imagine that it must have taken
many passes through the rolling machine and maybe with multiple
bending rolls probably all hydraulically driven.

If you read the post again it said 6" thick plate into 6' diameter,
that's 6 foot diameter and it didn't specify whether that was ID or OD.