Néhány napja szó volt Dan Gelbartról és az Ő shop tour-járól, azon belül is arról a tokmányállító mechanizmusról, amivel pikk-pakk le tudja csökkenteni a tokmány ütését.

Sokan kérdezgették a kommentekben, hogy miképpen is működik és a minap végre válaszolt is egy keveset.

 

A kérdés, amire válaszolt ez volt:

 

Could you please give give us more details of the runout adjustable chuck on your lathe at 13:20 - how do you achieve the adjustability without re-clamping?

 

Majd ezek a válaszok-kérdések születtek:

 

Dan Gelbart

The chuck is mounted to a hardened and ground A2 steel plate. This plate slides between two other similar plates attached to each other and to the lathe spindle. The fixed plates have 4 eccentric roller bearing cams driven by worm gears (about 50:1 ratio). Each pair of diametrically opposed worms is connected by a 6mm flexible shaft which is twisted to provide pre-load, so center plate is clamped in both directions by pairs of rollers with about 1 ton of force. To completely remove coupling between the two axes of adjustment, the rollers do not act directly on the middle plate but on an intermidiate U-shaped piece moving in a slot in the fixed plated and having linear roller bearings on 3 sides. You can skip this last step if you don't mind going back and force once or twice between the 2 adjustments. If you build your own chuck, like in my video on the air bearing lathe, the whole mechanism is inside the chuck.

 

Valaki kérdez

Thanks for the explanation! Did you just use mild steel for the flexible bars? Are the worm gears and torsion bars connecting by gears?

 

 

Dan Gelbart

Everything is hardened A2 toolsteel. The worm gears are connected by flexible steel shafts (like a wire-rope cable but designed for torsion). The self-centering chuck I have on my air bearing lathe (see separate video) is much more accurate, with play between any two parts(like jaws in slots) under 1 micron.

 

Valaki ismét kérdez

is it some worn of woven steel cable as opposed to twisted so it resists unwinding when turning the opposite direction? Is it held to the worm gears with like a clamp or set screw? I'm having a hard time making a mental picture.

 

 

Dan Gelbart

Yes, crimped to the worms.

 

Segítenétek megfejteni, hogy akkor ezt hogyan kellene elképzelni?