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Topic: Sierra Changer lockup problem |
mickd
From:
london,england
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Posted 18 Jul 2002 1:37 pm |
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well, I refixed a raise change on string 4 but it didn't do much because theres no string on there  . I don't want to put any more strings back on until this thing is fixed.
I finally tried Leon's procedure, albeit tentatively. I just pushed the changer axle in (using the clamp) until it was flush & then pushed it back again. I phoned Tom mid-way through for reassurance, as it was feeling a little stiff. I now have some confidence to go to the next stage with this manoevre, but first I'm going to try some high-pressure air, if I can find some - can't do any harm. If that doesn't do the trick, then its out with the axle.
Ole - when you pulled those 6 ends from the changer, which end were you pulling from ? |
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Mark Herrick
From:
Bakersfield, CA
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Posted 18 Jul 2002 6:33 pm
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I've been following this thread and am willing to bet at this point you're going to have to disassemble the changer.
You'd be surprised how much crud can collect in the axle and down between the fingers; microscopic metal filings, dirt, dried up oil, etc.
I did this with an all-pull changer once (not a Sierra though) and had no problems reassembling everything - and it worked great. Just get one of those plastic boxes with dividers, like you use for fishing tackle, and label each compartment. And make sure you document rod locations on the changer before you disassemble it. Clean everything real well with Naptha or Lacquer Thinner and maybe even some very fine steel wool.
It sounds like a daunting task, but when you're finished you'll really know the mechanics of that guitar. |
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Bobby Lee
From:
Cloverdale, California, USA
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Posted 19 Jul 2002 7:38 am
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If you go that route (tearing down the changer), be sure to write down which hole and bell crank slot each of the pull rods was in. That will save you a lot of grief when you put it back together.
I assign a letter ABCDE to the changer holes, and a number 1234 to the bell crank slots. I keep a copedent chart that has a code like B2 for each pull, so that if I have to yank a rod I'll put it back with the right leverage.
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 Bobby Lee - email: quasar@b0b.com - gigs - CDs
Sierra Session 12 (E9), Williams 400X (Emaj9, D6), Sierra Olympic 12 (F Diatonic) Sierra Laptop 8 (D13), Fender Stringmaster (E13, A6) |
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Ole Dantoft
From:
Copenhagen, Denmark
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Posted 19 Jul 2002 8:17 am
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Mickd,
When I pulled those string ends it was a major acrobatic challenge ! I had the guitar upright, then upside down, then ... etc. It's been 2 years since I did it, but I remember taking of several of the return-springs to be able to pull some from the underside of the changer, but I also remember pulling one from the bottom front-side of the changer - the one that faces the middle of the guitar. It took some time and patience, but I never had any tuning-problems with it again.
I'm not playing that guitar much these days, as I've got an Emmons P/P now, but I actually pulled it out of the case after reading this thread, and it still plays sooo smoth and actually sounds better than I remember, but maybe that's actually ME sounding better, who knows ?
Ole |
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mickd
From:
london,england
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Posted 19 Jul 2002 9:56 am
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Mark - I'm willing to take all the pull rods out, the springs and maybe even the changer axle, but thats as far as I would dare go. If that isn't enough then I'll have to find someone with more experience than me. I know my limits  .
B0b - noted; I have labelled all the rods and springs I've removed so far.
I just got back from a petrol station where I tried blowing into the changer using the air hose they have there but it was way too low pressure. I'll try the local tyre firm tomorrow as they should have an air compressor.
Ole - I reattached a string plus spring to the string 4 changer and worked the F lever with the guitar upside down but nothing fell out (yet)[This message was edited by mickd on 19 July 2002 at 10:59 AM.] |
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Jim Eaton
From:
Santa Susana, Ca
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Posted 19 Jul 2002 11:28 am
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Mick,
You may have already done this, but here is another idea.
Try standing the guitar on it's end, with the changer end to the top when you work the pedals/levers. I had good luck using that position to get stg ends to fall out of a Sho-Bud single neck. They would not come loose in the normal playing position or with the guitar turned upside down as if in the case, but with the guitar stood on its end, they worked free and fell out.
Good Luck
JE:-)> |
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mickd
From:
london,england
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Jerry Roller
From:
Van Buren, Arkansas USA
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Posted 20 Jul 2002 5:42 am
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Mick, the fact that it suddenly freed up could indicate that there was a broken string end in it and it dislodged but is still in the changer but currently not causing a problem. I would feel much better if you could get it (or them) out of the changer because it could jam it up again.
Anyway I am happy that your problem is solved. When you are satisfied that there are no strings ends in the changer I would suggest you do what someone earlier told you and use a piece of light foam rubber in the changer to stop this from happening again.
Jerry |
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Bobby Lee
From:
Cloverdale, California, USA
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Posted 20 Jul 2002 8:54 am
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I once had a changer bind problem that was caused by one of the little nylon bushings rubbing against the finger separation plate. Tom Baker advised me to whittle a sliver off of it with a razor knife. I did, and it solved the problem.
I'm not sure if your problem is related or not, but it's something to watch for. I hadn't mentioned it until now because there seemed to be a consensus that you have a string end stuck in there somewhere.
Good luck, Mick. Keep us informed!
------------------
Bobby Lee - email: quasar@b0b.com - gigs - CDs
Sierra Session 12 (E9), Williams 400X (Emaj9, D6), Sierra Olympic 12 (F Diatonic) Sierra Laptop 8 (D13), Fender Stringmaster (E13, A6)[This message was edited by Bobby Lee on 20 July 2002 at 09:57 AM.] |
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mickd
From:
london,england
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Posted 20 Jul 2002 11:58 am
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well, 2 steps forward, 1 step back ..
I reset the axle rod back to where it was to begin with and, to my surprise, the problem reappeared again ! Once again, I pushed the axle in about 1/4 " and the finger was free again.
Sounds to me like this proves it isn't a broken string thats causing the problem and it can't be B0b's 'fat bushing syndrome' either.
But if it's corrosion/gunk on the axle then how come the problem doesnt move from string 4 to string 5 as I push the axle in ?
I can only push the axle in until it's flush with the side of the changer (about 1/4"). I do this using a clamp. To get it further than that I would have to tap it through with another axle-like bit of steel. I have tried to do that, but its difficult. The axle is stiff and I am sure I would have great trouble ever getting it back to the starting position if I were to go so far as free up sting 1 (let alone string 4).
I'm stuck
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Jerry Roller
From:
Van Buren, Arkansas USA
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Posted 20 Jul 2002 1:08 pm
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Seems to me a broken string end is indicated. When the axle is moved the string moves maybe even wedging between the axle and the finger. Did you try moving the axle to a point where the finger was free and try to find or remove a broken string?
What a mistery.
Jerry |
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Jim Smith
From:
Midlothian, TX, USA
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Posted 20 Jul 2002 2:39 pm
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| I doubt that a string could get between the axle and the finger, he would see that. It sounds to me more like a groove worn into the changer shaft. One of Ricky Davis's tricks is to rotate the shaft 180 degrees to get away from the worn area. Any chance you can rotate the changer shaft Mick? |
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mickd
From:
london,england
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Posted 20 Jul 2002 3:43 pm
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Jerry - with the axle moved so that the finger is free, I still can't see a broken string end. Mind you, that doesn't mean there isn't one in there. Let's not forget, this whole thing started with a broken string..
Jim - if there was a groove in the axle, wouldn't that cause a problem to the next string (string 5 in this case) as I push the shaft through ? That doesn't seem to happen. The control finger on string 5 still moves ok even when string 4 is also ok. I haven''t tried to rotate the shaft. I hate to think how much torque that would take. How would I go about it - what tool would I need ?
I just talked the whole thing over with a friend in the pub. He wouldn't know a PSG if he fell over one, but he pointed out that my choice of '2nd shaft' (for tapping through) was not a good one. I took the only thing I could find that was the same diameter as the axle, namely a metal wood drill. Because the drill has a spiral cross section it won't transmit the hammer tapping force efficiently. So I will visit the local specialist hardware store and see if I can get a plain (unthreaded) shaft of the same diameter or smaller, then I can try again.
If I could bring myself to knock the axle the whole way through, then I could clean it up and also clean the finger bushings & then maybe it would slide back in easily.
Keep those ideas coming  |
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richard burton
From:
Britain
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Posted 21 Jul 2002 2:31 am
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Mick,
There is a saying: A little knowledge is a dangerous thing.
I detect from your postings that you are probably not very mechanically minded. My advice to you is do not carry on trying to fix this problem; take it to a competent steel mechanic before you damage it irrepairably. It horrified me when you mentioned the clamp, and tapping the shaft out indicates that a hammer is also employed. How do you know that there isn't a shoulder on the shaft, preventing it moving in the direction your hitting it?
I don't mean to put a downer on your attempts, but to me it really would be sensible to desist immediately, and take it to a reputable repairer. |
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mickd
From:
london,england
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Posted 21 Jul 2002 3:25 am
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Richard - your deductions concerning my mechanical abilities are spot-on !
Its ok to tap the axle through though - I checked with Tom @ Sierra, and thats how he does it. I think I've almost reached the end of the line in terms of what I can do, so I will probably be giving Mr Wiggins a call soon (do you know him ?). But having got this far, it would give me a lot of satisfaction to get that axle rod out and to be able to lift the control fingers and maybe see a pesky string end in there[This message was edited by mickd on 21 July 2002 at 04:29 AM.] |
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Bobby Lee
From:
Cloverdale, California, USA
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Posted 21 Jul 2002 7:43 am
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| The string end did disappear when the string broke, right Mick? |
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mickd
From:
london,england
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Posted 21 Jul 2002 11:24 am
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B0b
yes - it did disappear, but I can't be sure it didn't end up on the floor somewhere. I did have a scout around and couldn't find anything. The break was at the changer end.
Mick |
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mickd
From:
london,england
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Pete Burak
From:
Portland, OR USA
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Posted 24 Jul 2002 4:21 pm
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Insufficient Lubrication...
If I had a nickle for every...
Just wait 20 min and try it again Mick.
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mickd
From:
london,england
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Posted 25 Jul 2002 2:11 pm
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Pete - its going to take me a lot longer than 20 minutes to get all the pull rods back on !
Anyway, now that its all disassembled, I'm taking the opportunity to clean & lube everything in sight, plus swap out the A-pedal and Pedal 5 aluminium cross-shafts for the special steel shafts I had made to (hopefully) eliminate the infamous U12 torsion effects. I've been pleasantly surprised at how easy it was to pop out the shaft bushings and install the new shafts. Fingers crossed that when its all back in one piece BOTH the problems will be solved.
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Sierra Session U12
homepage
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