Re: BT30 drawbar

Forgot to add,

The older parts had three "fingers"; rather than ball bearings in
ramped holes of a solid

These fingers were high tensile and hardened steel. Their general
shape was/is
___
_____/ \

With the left end at the top. the left end has a small protrusion
that acts as a hinge in th ecylinder-shaped part that the three
fingers fit into at assembly.

You can see a "one-piece" Homebrew version of this at teh
Buildyouridea link i just mentioned.

Back to the big machines:
The spindle bore has a matching set of ramps, and the rightmost \ of
the finger is what pulls on the holder stud.

Hope this helps,

Ballendo


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Henrik Olsson" <henrik-
olsson@...> wrote:

>
> Hi guys,
> What is the most common design of the drawbar for a 45degree BT30

pullstud?

> I mean the part that actually grabs the holder and pulls it

up/into the

> spindle. I imagine some kind of tapered "thingy" with balls that,

when

> pulled up, pushes the balls in making contact with the chamfer on

the

> pullstud. When the drawbar is pressed