Rick Hamelin on fri 16 may 03
Hi
I am building a slabroller with motorized feed and was wondering if anyone
knows the rate of travel to roll out most slabs?
I am building a top, double stepped roller carriage that will pass over the
clay. The first roller will do the initial clay compression and the second
roller will complete the slab to thickness. This will be riding on a linear
bearing mounted onto a rod on either side of the roller ends, the rods running
the length of the table.
I am considering either single or double screw drives or a cable and pulley
perhaps using a garage door opener for the pulling mechanism. A second motor
willbe used to rotate the rollers.
Any thoughts?
Rick
Fredrick Paget on fri 16 may 03
This sounds like quite a project and I am wondering if it isn't overkill? I
offer this as a critique and no offence should be taken.
You really don't need 2 rollers - one is enough, and having two might make
a trap for clay and canvasses to get caught in between. Also if you pull
the roller along with a motor or hand crank moving the roller carriage it
will rotate by itself and you won't need a second motor.
I also wonder about the linear bearing running on a rod. Unless you make
the rod very large in diameter it will be pulled upward - that is bowed
upward, as the carriage goes through its travel. As a result the slab will
be thicker in the middle.
I saw a neat little slabroller in Portugal when I was there this spring. It
had a single roller on a moving carriage which ran on little wheels about 1
cm. wide. There were 4 sets of wheels attached to the corners of the
carriage. Each set had 2 wheels. The top wheel rested on the outward flange
of a stout angle iron on each long edge of the table. The bottom wheel of
each set was under the angle iron flange to keep the roller carriage from
rising.
The carriage was pulled along by two loops of stout motorcycle chain - One
on each side under the table. There were two shafts with 2 sprockets each,
one under each short edge - the ends - of the table. The chain loops were
fastened to each end of the carriage under the table and around the
sprockets under the table. The sprockets were about 10 cm. in outside
diameter. The right end shaft had five or six rods screwed into a collar on
the shaft to make a hand capstan type arrangement to rotate the shaft and
pull the carriage along. There were gear shift knobs on the ends of the
capstan rods to make them hand safe and friendly.
Slab thickness was set by putting sheets of masonite under the roller.
It would not be hard to motorize this arrangement. The speed would be
determined by how powerful a motor you used.
When we were in Japan last year at the Aomori Woodfire Festival I used a
Japanese slab roller that was a real killer. It ran at about a centimeter
per second and once it got going stand clear and watch your fingers and
hair (not a problem for me!).
Good luck and let us know what you come up with when it is done.
Fred
>I am building a slabroller with motorized feed and was wondering if anyone
>knows the rate of travel to roll out most slabs?
>I am building a top, double stepped roller carriage that will pass over the
>clay. The first roller will do the initial clay compression and the second
>roller will complete the slab to thickness. This will be riding on a linear
>bearing mounted onto a rod on either side of the roller ends, the rods running
>the length of the table.
>I am considering either single or double screw drives or a cable and pulley
>perhaps using a garage door opener for the pulling mechanism. A second motor
>willbe used to rotate the rollers.
>Any thoughts?
>Rick
From Fred Paget, Marin County, California, USA
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