Knee lever tension

Dan Neave · Post by **Dan Neave** » 23 Jul 2023 2:11 pm

Hi mechanically minded Steelers,

Any idea how to take some stiffness out of my RKL (Eb) and RKR (G#) knee levers.
My LKL and LKR not only have less play to hit the semi tone, but also are much easier to move than my Right side knee levers. I feel with the levers on the right side I am always fighting them and want a lighter response if that makes sense.
With the RKL (Eb) lower I also notice the pull rod sits in the lower hole at the changer finger and the return spring rubs with the rod when engaged. Also pull Rod sits in the lower hole of the bell crank which may or may not need to? Finally the same E lower pull rods/hex screws sit lower in the changer then all the other pull rods/hex screws which I am not sure contributes to the tightness.
The machine is a ZB custom SD10 with Shobud changer and plays well, I just would like to lighten my touch on the right knee levers if not too difficult to do. I see the pull rods seem to just unscrew from the bell cranks with the right screw driver and happy to have a play around with something like this if need to.
See images for a bit extra info.

Regards,

Dan

Bobby D. Jones · Post by **Bobby D. Jones** » 24 Jul 2023 8:27 pm

The way the picture shows the Eb pulls, With the pull rods in the hole at the end of the Bell Crank. It should take a lot of pressure, But rather short move.

Its a rule of physics.
The farther the Pull Rods is from the the cross rod in the Bell Crank. The shorter the move to note, But more power needed to move the lever.

The closer the pull Rod is placed in the Bell Crank to the Cross Shaft, The longer the pull to note, But takes less power to move the lever.

Since you have pictures of the present Bell Crank and Changer holes. You can return to the original holes.

Move the Eb pull rods half way up the Bell Crank and check the difference.

The hole in the Changer Finger, The closer to the Changer Axle the quicker the move, But needs more pressure.

Good Luck finding the right combination of Bell Crank and Changer holes to get the pulls you want. Happy Steelin.

Ron Pruter · Post by **Ron Pruter** » 30 Jul 2023 7:53 pm

Those springs should not be stretched like that on those 2 strings. In a relaxed position every changer finger should be pulled back against it's return position. all fingers and springs should kind of, look the same. Over tuning could be a cause. Read about Overtuning in the beginning of this section. Good Luck...Ron

Bobby D. Jones · Post by **Bobby D. Jones** » 30 Jul 2023 11:34 pm

Ron Pruter, (I messed up) I missed those lower return springs being stretched that much. On strings 4-8. I was concentrating on the Bell Cranks to change the pressure and movement on the knee levers.

It looks like it is over tuned.
That is the first problem to get worked out, And get the lower return levers lined back up.

Dan Neave · Post by **Dan Neave** » 1 Aug 2023 3:06 am

Hi Bobby and Ron.

Thanks for the info. Those e lower return springs are engaged in that picture FYI.

Regards,

Dan

Dan Neave · Post by **Dan Neave** » 1 Aug 2023 3:07 am

I engaged them to show you guys how the springs slightly rub and make contact with the pull rods.

K Maul · Post by **K Maul** » 1 Aug 2023 4:13 am

I’d try moving the rod up two holes on the left and down two or three on the right. You may find a good balance with some experimentation there.

Donny Hinson · Post by **Donny Hinson** » 1 Aug 2023 3:31 pm

I could be wrong, but that looks like way too much finger movement for an E-Eb change. I'd cut about 1/2" off of that long (home-made) 9-hole puller, then realign and rebalance everything.

Pulling linkages should always line up parallel, or almost parallel:

like this |-------|

or this /------/

or this \------\

NOT like this /------\ or this \------/