Power DrawBar Mechanism

[vmax549]

Can anyone explain the mechanism that holds the tool holder in place with a power drawbar system. Something like a modern setup that has a pin in the top of the toolholder. I am working on an auto tooler changer and need to know the best approach for holding the tool holder in place. A picture or diagram would be helpful, or point me in the right direction(web site). Thanks Terry Parker

[machintek]

On a series 1 std, the power draw bar is an air impact wrench turning the R-8 drawbar or a QC30 drawbar. VMCs have either an air cylinder or hydraulic cylinder working against a drawbar that has a stack of spring washers that work holding the collet up that holds the tool retention knob. Typically anout 2000 pounds of force. Yes you do need diagrams.

George

[vmax549]

Hi George thanks for replying. I was thinking about the VMC approach but I don't know what the finger mechanism looks like. I was planning on using a spring pack on top with an air cylinder to push on the spring rod to release the fingers. Would you know where there may be a picture or diagram of this mechanism? Terry

[machintek]

Attached are two diagrams. One is of the air cylinder for the release fof the tool. The other is a cross section of the spindle. Note that the air cylinder floats. It will rise up and grap the exterior of the spindle, at which point it pushes down on the drawbar. Similar to a siringe. This is so that the spindle bearings do not take the force of the air cylinder.

George

[vmax549]

Thanks George I appreciate the help. Terry

[vmax549]

George the diagrams were a big help. Thanks Would you happen to know the TPI on the Boss feedscrews? I am getting ready to make the control retrofit operational and need to know the feed screws TPI to set up the software. Thanks Again, Terry

[machintek]

If you mean a Series 1 Standard, the x and y are both .200 inches per rev.
The knee I would have to measure as although the dial is .100 inches per revolution, it goes to a set of bevil gears of what ratio, I do not remember.

George