Re: Table mounted tool changer

In a message dated 01/20/2000 5:09:51 PM Hawaiian Standard Time,
daveland@... writes:

<< From: daveland@...

Has anyone ever seen a table mounted tool changer on a mill?
I was thinking of designing one to hold 4 or six tools. The CNC
program would be written to position itself over the proper place and
activate
the power drawbar. The holders would be placed at specific coodinates and
each
tool cold be fetched at will. spring loaded stop prongs would keep the NBT-40
tooling from spinning during the change.

What is wrong with this idea? I seem to see very complex carrousel
arangements
that bolt near the column. They also have complex retention mechanisms that
avoid threads and opt for buttons or nubs. I guess breaking the taper away is
a big issue.

I guess people want speed and flexibility in a MFG environment. An the
table
mounted tool changer is far away and takes up table space.

dave >>
Dave,
My day job uses a Thermwood wood router. It is a BT-30 taper equipped
machine. The tool changer is a 6 tool rack style unit. The one major snag
with it is it takes up work space. If the spindle can go to the location of
the tool rack, that means some of the usable machine travel has been
sacrificed. The tool holder are always dirty. That means that careful
operators have to clean the holder with a rag or blow down with air every
time a tool change is called for. I suppose a programmable air nozzle could
be used but the effectiveness is still questionable. Wood dust cakes up on
the taper causing unacceptable tool runout. A small sliver of metal would be
the same. If one was to create an air operated cover, the whole thing would
take even more space. Just my observations.
Peter