Upright loss of repetition

[William R. Monroe]

Comments below:

>
>> Also, I'm unclear how filing away felt from the strike point affects the
>> jack to butt clearance.
>
> Because the hammer has a longer distance to travel.  The jack is still
> pushing on the butt when it normally would be beginning to trip out.
> That equals less clearance at the end of the keystroke.  Bill
> Spurlock's Vertical Regulation booklet has a good illustration of
> this.

I don't understand.  When the jack trips out is dependent upon where the 
let-off button is set, right?  So, if ALL you did was file away felt, the 
jack still trips at the same time relative to keystroke, but too early now 
relative to let-off.  Picture the hammer, held at let-off, jack just 
starting to trip.  Now file away 1/2" of felt.  Let-off is now 5/8", but the 
jack still trips at the same point in the keystroke, yes?  Same clearance as 
before filing.

Now, if you failed to adjust blow, but then DID adjust let-off back within 
specs, I'd agree that you would have a problem with not enough clearance, 
and bobbling hammers, no doubt.


>
>> I would think it would be let-off that is now a problem
>> (too great) and probably checking, and................
>
> Probably not...IF it wasn't a problem before, and IF you didn't change
> the blow distance all that much.

Ha!  You're using Bonetti's defence against me, huh?!

>
> One thing you might check is the lost motion, since you adjusted that.
> It might be set too close, which definitely causes poor repetition.
> The correct check for proper lost motion is when the jack returns
> under the butt when the key is released very slowly.  If the butt
> leather is worn, you might have to allow greater lost motion.
>
> -- 
> JF


I will double check my blow/lost motion, etc. when I return.

William R. Monroe