10ee Square dial QCGB tumbler lever

[Mr_CNC_guy]

I finished the job and here is what I did.

I adjusted the lever such that there is zero slop when
the lever is locked into place. This causes the gears
to have the backlash as set by the factory.

As it turns out when the lathe is running forward doing
normal threading the change gear (the one on the swing)
is forced into engagement. Thus the backlash is set
by the two adjustment set screws and not by any slop in
the lever.

When the lathe is run in reverse then the change gear
is being forced out of engagement and only held in
place by the spring loaded pin in the lever. The
lathe is rarely run in reverse under load so this works OK.

Looking closely at the tapered holes in the lever and the
shaft I can see that one was drilled at a slight angle
to the left of perpendicular to the shaft and the other
was drilled slightly to the right. There was no way that
a pin would go through.

However the two holes were very close so re-drilling one
to align with the other was impractical. In the end
I just ran the reamer in further cutting both the shaft
and the handle. I made a pin and tapped in in place
to finish the job.

Here is a picture:




This shows the amount of engagement of the spring loaded pin.
You can just barely see it.

 

[m-lud]

Those pins are short. Welding would be hard to do. Mahe o ne thats longer?

 

[Mr_CNC_guy]

Could you pull the pin out of the handle and weld a little more length to the end. Cant tell how mich is in there

That pin is the spring loaded pin that the chrome knob pulls back.
It is the factory length and is tapered on the end. The way I finally
did the adjustment was to have the wedged portion of the pin rest
against the face of the housing. That way the spring pressing against
the housing holds the gear into engagement.

The pin is almost fully extended as you see it. I know that the picture
does not show it very well.