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venco 4" vacuum

updated mon 30 jun 97


Dan C Tarro on sun 1 jun 97

Fellow clayart readers,

The following is an inquire I made to Marshall, a clayart subscriber,
pertaining to a vacuum problem and question about the structure of the
Venco 4"pugs. He requested that I pass the question onto the rest of the
list for response. Your input is welcome.

>I am having a problem that seems to have a history with Venco from my
memory of the posts in the past. Didn't pay attention to them at the
time because I didn't own one. Picked up a second hand one. The pug
didn't have a vacuum pump with it so I pulled out one of our old Gast
pumps and hooked it onto the unit. The problem is the vacuum chamber.
What should I expect from this pug? The unit pulls clay into the vacuum chamber
There is a vertical plate of sheet metal that protrudes slightly into
the clay as it enters the chamber segment. Do you know if this is there
to limit the clay and keep it from backing up into the vacuum ports? It
seems to match the inside diameter of the rest of the mill. If so should
it be projecting further into the mill to block the clay from the height
of the ports? The pug operates with about a half inch skin of clay stuck
between the auger and the housing. I would assume this to be normal, but,
it also runs the length of the vacuum portion of the housing. I would
think that if this plate was placed closer to the auger it would
interrupt this skin at that point to let the vacuum through.

What do you think? I know about the limiting of the volume of the vacuum
to prevent it from pulling the clay into the chamber. It still migrates
into the ports. Am I missing something?

Also did you get any kind of manual with yours for parts or service? I
talked with the local supplier and he said they, Venco, never had one
for it.

Interested in what you have to say,

Dan Tarro
Oak Tree Stoneware
Ham Lake, Mn

Ray Carlton on tue 3 jun 97

At 12:15 PM 01/06/97 EDT, you wrote:
>----------------------------Original message----------------------------
>Fellow clayart readers,
>The following is an inquire I made to Marshall, a clayart subscriber,
>pertaining to a vacuum problem //snip

hi dan i got one of those but mine has the proper vaccuum setup by venco it
works great i got a couple of a4 photocopied sheets with mine which is all
there was. it covered setup and very basic maintenance [lube etc] you
problem probably stems from adapting foriegn bits to fit the machine

Ray Carlton McMahons Creek Victoria Australia

Craig Martell on wed 4 jun 97

Hi Dan:

Sorry to be a day late and a dollar short with this post but I've been
making pots again and it cuts into my internet activities.

Venco mills can operate at full vaccuum with 95% of the deairing chamber
full of clay.

The vertical plate in the deairing chamber has two small dogs on it that
hold the horizontal plate in place keeping the opening at about 1/4 of an
inch or so to allow the clay to be deaired. This vertical plate should not
extend any closer to the auger.

The 1/2 inch margin between the auger and the inside of the barrel is normal
and that's the way the machines are built.

Does your vacuum guage work? You should be getting somewhere between 85 and
95 Kpa on the guage to achieve good deairing. What is your clay like? Is it
coming out OK? Any problems? If not, don't worry about clay in the
deairing chamber. If you are pugging and it gets REAL full, open the pump
by pass valve, take off the plexiglass plate and scoop out the excess clay
and go happily on your way.

Hope this helps, Craig Martell-Oregon (ex Venco agent)