moving lever 'collapse' on Sierra Session

mickd · From: london,england

A while back, I added an extra change to my E-lower lever (LKR) on my 12-year old Sierra Session. The new change is a long throw (string 2 from D# to C#) so the lever (which is a moving lever) now goes a lot further than it did before. Consistently, I observe the following
1) all adjusted ok and off I go
2) plays fine for a while (a few hours if I'm lucky), then suddenly the lever 'collapses' and goes almost horizontal. I have to pull it back into position. Once its happened once, it happens all the time so I have to get underneath...
3) I now find that the ball/socket joint has rotated out of line. I can't really see why this should happen nor why it should matter (doesnt matter on my other moving lever, but that is a shorter throw). I rotate the joint so that its 'straight' again, and I am ok for another hour or so.

I have posted a slide-set here that shows the problem better than I can describe in words.

Is the answer to this to use loctite on the nuts at either end of the threaded bolt once I have the ball/socket in the straight position ? Would that stop the rotation ?

Does anyone else experience this problem ?

I know that Sierra brought out a modified lever that has an adjustable stop on the lever head itself - in theory this would stop this behaviour causing a problem. I had one of these sent over but unfortunately it doesnt fit (seems like my guitar has some non-standard measurements and theres some things you just can't sort out over the phone - especially at International Rates

).

Hope someone can help. Its really unnerving wondering if the lever is going to give way every time I engage it

Mick

[This message was edited by mickd on 30 March 2003 at 02:13 PM.]

C Dixon · From: Duluth, GA USA

mickd,

The ball and socket are held in a given position by a threaded shaft AND nut; away from the ball and socket.

In other words, follow the shaft coming out of the ball 'til it connects to another shaft. Somewhere along here there should be a nut that can be tightened; that will hold the ball in the socket at a given position.

I am using memory recall (since I no longer have my Sierra). But it seems to me that I can see that nut in my mind. At any rate, see if there is not a nut threaded onto a shaft that may have loosened.

If not I am not sure what might be wrong.

May God bless you in your quests,

carl

Michael Johnstone · From: Sylmar,Ca. USA

It looks to me like you've got way too much travel in that lever. Even with the changes you've got on there it should pull them all without going that far. That ball and socket gadget which is actually the reversing mechanism, is losing machanical advantage after a certain point and "collapsing" as you call it.It's just not meant to travel that far. It has very little to do with whether the shaft is curved or straight.

Dennis Boyd · From: Suisun City, CA USA

Mickd,

Try loosening the holding plates for that knee lever and slide it slightly away from the bellcrank shaft. This will tilt the lever in slightly but also give the ball joint more travel from a lower center line.

You can also do this by unscrewing the threaded rod that attaches the knee lever to the bellcrank shaft a few turns. This will also push the lever into an inward tilt so that you get a constant positive travel.

What's probably happening is the ball joint is reaching its limit and then begins letting the knee lever change direction. This allows the lever to push the threaded rod off center until it bottoms out in the new direction. Results, far too much travel.

Let me know if that works for you. Good luck.

Dennis

Bill Crook · From: Goodlettsville, TN , Spending my kid's inheritance

After lookin' at the photo's for a while, I have to ask.....

Why dose the shaft that has the "ball" on it,have a curve in it ???

If this shaft was stright, it wouldn't make any difference if it rotated around or not. The "ball" can rotate in the "socket" all day long and NOT change the angle of the lever. Also, as the "ball" is constantly changeing angle in respect to the "socket",when being activated,the travel,pressure,and other forces should remain consistant. As it is in the photo's,I can see everything changeing should the shaft rotate more than 2 or 3 degrees.

C.Dixon's thoughts of a "nut" being placed onto that shaft is a good idea if that shaft is threaded. As he states, This would hold the part at a given position.

I'm just a "novice" in this area so if I show any signs of not understanding exactly how this lever works,just call me another "NUT"......

Michael Johnstone · From: Sylmar,Ca. USA

The angled ball gadget is for going around slight obstructions in its path much like pullrods with dogleg bends in them. The more I think on it MickD,the way you describe it as a "moving knee lever" added to the problem you are having tells me you or someone else HAS moved the lever in its slot without changing the length of the ball & socket connecting/reversing shaft accordingly - causing the lever to under or over extend - depending on which direction it was moved.This would account for the problem you are having. It could possibly also explain any problems you might be having with your lever lock.Also somewhere in your post you wonder if you should put loctite on there - you shouldn't need it because there is(or should be)a lock nut on there which when locked down w/minimal torque will hold the desired angle indefinately. But....by nature,ball and socket clevises have a little twisting play in them but again,this is not the root of your problem.Just change the length of your ball shaft assembly.Another thing I would look at(besides the fact it's not a very good musical idea to put the 2nd string lower on your E-D# lever - it subtracts a full 2/3s of the combinations otherwise available by having them on seperate levers)is changing the bellcrank hole and/or the changer lowering hole on your new 2nd string D#-C# change. -MJ-

C Dixon · From: Duluth, GA USA

Michael,

I too have come to the same conclusion you did after thinking about it. This may have been due to him trying to get more travel at the lever; rather than at the bellcrank and/or changer.

This is a common scenario I find. Remember folks, when trying to obtain more travel, first move the point on the bellcrank further from its pivot point or move the point on the changer closer to the pivot point; OR, both!

While this is easily and inherrently "seen" by mechanically oriented ppl, it can be quite elusive to those who do not have that aptitude.

Finally, the main reason the connecting rod is bent, is due to the very close tolerance the ball is to the bottom of the cabinet. IMO, it was and is a poor design.

The Sierra is a mighty fine engineered PSG, but those "right" moving levers leave a lot to be desired. If you doubt this try to remove one for repair or replacement. And if you don't cuss, you are a Saint!

The ONLY thing I know of that is worse on a PSG is trying to remove a crossrod from an Emmons' LeGrande. That fluke has got to win the award for being THE dumbest thing EVER been on a PSG. IMO

carl

[This message was edited by C Dixon on 31 March 2003 at 09:25 AM.]

mickd · From: london,england

thanks everyone for all the great feedback.

Yes, there are stop nuts on the thread - thats where I was thinking about applying Loctite. I can't seem to get them tight just with my fingers & don't have a spanner that will fit in there.

I agree that the travel seems excessive. Trouble is, I have already tried every combination of changer slot and bellcrank hole. This combination (lower slot 'E' and bellcrank slot '4' - the furthest from the guitar top) is the only one that works - the others are either too stiff or else cause other problems.

The consensus seems to be for me to move the lever further to the right (i.e extend the threaded rod & shift the lever). I will try that.

I should have mentioned that in an effort to resolve the problem I already (before I started this thread) moved the lever to the lower of the 2 pivot points available on the crankshaft mechanism. Should I undo that ?

Finally, I thought the idea was to set up the lever so that it hangs vertically i.e decide on the position of the lever on the body, then set the threaded shaft length such that the lever hangs staright down. Is that not so ?

[This message was edited by mickd on 31 March 2003 at 12:20 PM.]

Michael Johnstone · From: Sylmar,Ca. USA

Either of those pivot points will work although as you no doubt know,the one it's in now will be the stiffer of the two. But there's no reason you can't have those 3 changes on there(apart from the musical reasons per my earlier post)and still have a reasonably playable knee lever with a normal throw.And yes a knee lever at rest should hang straight down and when fully engaged,the tip should not have traveled more than 1 or 2 inches - much more than that is excessive. I would also suggest that if you own a pedal steel guitar - especially a nice instrument like a Sierra,you should not hesitate to obtain the 3 or 4 tools necessary to keep it in proper adjustment. That and an intimate knowledge of the mechanics of your guitar will serve you well. -MJ-

mickd · From: london,england

you wouldn't believe the trouble I had getting imperial (non-metric) Allen keys over here. When I was at school, it was all feet & inches but now metres etc seem to have taken over in the UK

Anyway, I just measured the lever throw and its moving 2 1/2" (this after I lengthened the thread rod a few turns).

A few months ago, I moved the LKR change from 4/E to 4/D (thats bellcrank slot/lower finger for non Sierra owners)to make the throw shorter. Trouble is, I had to move another change to make room for this (the string 2 1/2 tone drop) and I now found that operating the LKR caused the pull rod on the other lower to move so much that it sometimes disengaged from the bell crank and then got stuck on the way back (hope this makes sense). Maybe I'll try that again and start a new thread if I can't fix the side-effect problem.

Michael Johnstone · From: Sylmar,Ca. USA

What you want to do when the delrin barrel wants to slide out the back of Sierra bellcrank slots is this: Get a small brass or steel collar with a set screw in it and put it on the pull rod just ahead (1/8")of the bellcrank. This will act as a keeper and allow some play but not enough to fall out the back of the slot.If you're like me you'll have a bucket full of parts from every known pedal steel ever made - if not, then such collars can be had at hobby shops specializing in RC airplanes/helicopters. And I'll bet if you get on the horn in a place with as many resources as London you could find any sort of tool you desire.If you can't,e-mail me and I'll hook you up -MJ-

Ed Mooney · From: Evanston,IL

Mickd, I have a 3 year old Session U12 and I like you, have tried every concievable way to get that change and have run into the same problems....way too long of a throw plus the fingers on the changer of the D# would get all out of whack when I tried to tune it to C#. At last years PSGC in St. Louis, Jeff Newman expressed his opinion that you can't get that change on a Sierra. I called the factory and was told that it wasn't possible without that excessive long throw. Ed

Bobby Lee · From: Cloverdale, California, USA

I have D# to C# on my Sierra Session, on LKR. It's a longer travel than the other levers, but it works fine.

------------------

Bobby Lee - email: quasar@b0b.com - gigs - CDs
Sierra Session 12 (E9), Williams 400X (Emaj9, D6), Sierra Olympic 12 (C6add9), Sierra Laptop 8 (D13), Fender Stringmaster (E13, A6),
Roland Handsonic, Line 6 Variax

Michael Johnstone · From: Sylmar,Ca. USA

I have it on a 1994 Session U-12 on RKL. Measured at the tip of the lever the travel is 1.75 inches and the half-stop kicks in at 1 inch. Like I said, I know some guys put that change on the E-Eb lever but my whole approach to the E9 chromatic strings would be out the window if my guitar was set up like that.

mickd · From: london,england

Michael
the collar's a great idea

- I am having a similar problem right now with C pedal causing the Pedal 6 raise on string 4 to overshoot (doesn't bother me too much as the C pedal is the only one of my 8 I can live without) so I could potentially use that trick in 2 places. If I understand you right, I put the collar on the changer side of the pull rod and screw it down so that it won't budge; when a 'phantom' pull takes place on that rod, it will then limit the travel. Sounds like I might be able to test this using one of those little plastic doo-dahs you use to join two electric cables together - should have some in my toolbox. Anyway theres a modelling shop round the corner so I will try there.

I have now found a 3/8" spanner but can't see how the nuts on the ball/socket rod can really be 'tightened', as the axle on which they turn is itself free to rotate in two directions

...in any event the adjustment I made the other day has worked so far (touch wood) in that there has been no further 'collapse'. If I can get the collar idea working then I may be able to reduce the travel further and then it sounds like I can probably forget about the rotation of the ball/socket combination anyway.
Ed
I have had the C# change for a long time now, and I suppose I got used to the long throw. It isn't ideal, but its only the 'collapse' problem thats a show-stopper - I can live with the long throw if necessary. If I manage to reduce the throw by changing from 'E' to 'D' I will let you know.
Mick

Earnest Bovine · From: Los Angeles CA USA

FYI, the Yank's wrench is the Limey's spanner; e.g. Jesus El Pifco.

mickd · From: london,england

Earnest
We have a 'wrench' too - but it means a very big spanner with an adjustable business-end (via a screw thread on the side).
Two nations divided by one language

Mick

mickd · From: london,england

Progress :
1) I reverted back to the original lever pivot point as the change of pivot was just an experiment
2) I moved the D#->C# string 2 change from 4/E to 4/D and moved the D#->D change from 2/D to 4/E. Previously this caused problems but this time I followed MJ's tip and applied a 'collar' to the D#->D pull rod to stop the 'overshoot' problem. The collar works a treat, but (strangely enough) the end result is that the throw is just as long as it was before

Anyway, the 'collapse' seems to have gone away so I'm not complaining

The 'collar' I used isn't perfect - it gets in the way a bit when you tune from the endplate as it catches on neighbouring rods as it rotates. This is easily overcome but long-term I will replace these with something a bit smaller in profile.

I also applied the collar on string 4 which fixed the overshoot problem I had with the C pedal

Mick

[This message was edited by mickd on 03 April 2003 at 02:27 PM.]

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