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Removing and cleaning Sho-Bud changer

Posted: 5 Sep 2018 7:03 am
by Garry Moore
Is there a correct way to take out this changer from a 6139 sho-bud? It's the wood wrap-around era. I just installed some additional knee levers and rods and now some of the fingers won't return to the zero point.

I noticed whenever I'd install a rod some goopy waxy stuff would push out and so it's probably time for a deep clean.

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Posted: 5 Sep 2018 12:09 pm
by Gary Patterson
That looks like the same changer I have in a Crossover I recently bought in pieces.

I would start by removing the tensioning screws from the springs shown in the foreground of your photo. This will leave them dangling from the changer, and you shouldn't need to bother removing them.

The smaller springs shown underneath are probably just hooked to something, and don't have adjustment screws. Again, let them dangle from the changer.

Now, you should be ready to remove the four mounting screws on top, and the two underneath. The changer should then come out from the top.

You may want to drive the pivot pin out of the changer body to release the fingers, one by one. This will allow you to thoroughly clean them. I used naphtha and a bronze wire "toothbrush" to clean everything and then lubed it all with dry Teflon spray lubricant. You'll probably hear from others about their favorite choice of lube.
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Posted: 5 Sep 2018 4:45 pm
by Lane Gray
You don't have to remove the tailpiece to remove the changer.
Remove the strings
Remove the barrels from the rods (disassemble the barrels while you're at it, clean them BUT DON'T LUBE THEM)
Remove the rods (I put them in the chuck of a drill and clean them with Meguiar's Cleaner Wax)
Remove the return springs (might as well clean them; if you have a hobbyists' tumbler, that'll make them shiny again)
Remove the helper springs.
Drive out the axle, probably one finger at a time, and remove fingers.
Clean the axle
Clean the fingers, possibly carefully dress any grooves. If any pivot rivets are wobbly, GENTLY repeen them; you want them to prevent wobble, but pivot freely.

If you stay focused, you should be done in two days easily (one if you push it), unless you tumble the springs, since that usually takes a few days to a week.
If you want to add complexity to the job and make the underside shine, you can remove crossrods or racks

If you want it shiny, by all means, remove the tailpiece and endplates, and take them to your local metal polish place (if you don't know one, ask your biker or hot rod friends who they'd recommend, and I don't know any musicians who don't have biker or hot rod friends). And while you have the metal off the wood, clean and buff the wood. If you're gonna give the guts a clean, might as well make the top gleam.

You can give it a weekend and make it better, or give it longer and make it a showpiece. Given that my life is short on time, I'd probably just do the moving parts.

Posted: 6 Sep 2018 6:12 am
by Gary Patterson
I like the idea of tumbling the springs. Wish I'd have thought of it -- I have the machine. I just scrubbed them clean with naphtha and the aforementioned bronze brush. Clean, but not shiny.

What is this "tailpiece" you refer to?

Posted: 6 Sep 2018 9:24 am
by Mark McCornack
Hi Garry,
Is it your 4th string not returning? The picture you show looks like the lower plate on that finger isn’t engaging all the way back to the bezel. One thing you might try is tightening the screw on that return spring a few turns to give a little more oomph to return that changer finger to neutral.

That said, I don’t discourage tearing it down and doing a thorugh cleaning! I did that for the first time on my Pro-I recently, and is isn’t really as daunting as it seems. A little time consuming, but (in my case) worth the effort.

One word of caution. If you do a full tear down, on re-assembly be careful when re-engaging the 6-32 screws in the return spring nutserts. If not engaged cleanly, these can drive the nutserts up the spiral of the spring when you go to tighten them, never again to see the light of day! Been there, done that.
Mark : :)

Posted: 6 Sep 2018 1:26 pm
by Lane Gray
Gary Patterson wrote:I like the idea of tumbling the springs. Wish I'd have thought of it -- I have the machine. I just scrubbed them clean with naphtha and the aforementioned bronze brush. Clean, but not shiny.

What is this "tailpiece" you refer to?
On a wooden-necked Bud, Ricky Davis (and perhaps the late Mr. Morehead called the aluminum bit that has the hole for the pickup, and the slots for the fingers, the "tailpiece". The term also works for the classic MSA.
Let me rummage for a picture.

[rummages through the for sale section of the forum]
This bit.
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Posted: 6 Sep 2018 3:40 pm
by Garry Moore
Mark McCornack wrote:Hi Garry,
Is it your 4th string not returning? The picture you show looks like the lower plate on that finger isn’t engaging all the way back to the bezel. One thing you might try is tightening the screw on that return spring a few turns to give a little more oomph to return that changer finger to neutral.
Yeah, not sure why it's not returning. It was playing great and staying in tune until I added this last RKR knee lever. I reeeeally don't want to tear it apart and clean it--I just want to play. I turned the screws on the back side under where the pull rods are inserted but nothing really changed.

I was in a big hurry after putting it back together and I hadn't yet installed the last stop and cranked it and somehow the fingers have got stuck. Not sure what it's hung up on. Maybe it just needs re-seated?

Posted: 6 Sep 2018 4:10 pm
by Mark McCornack
I know your reluctance to tear it down, but in retrospect, I’m glad I did mine. It really wasn’t all that bad. Just keep track of all the little bits.

If you do a complete tear-down, there’s no reason not to remove the “tailpiece” too. The pickup doesn’t have to come out or even move. It’s just four wood screws, and this will allow you to more easily clean in between the sides of the slots where the fingers go. An important step in the cleaning process IMO. Plus, it’easy to make it all PURDY that way.
Mark :D

Posted: 6 Sep 2018 10:12 pm
by Mark McCornack
Hi Garry,
One thought came to mind after reviewing your picture of the changer and re-reading your text. On the picture, it appears as though the first string raise tab (for want of a better term) is way out of neutral position and has jumped out of the track on the bezel. Let me explain.

Below is a picture of my Bud Pro-I back bezel. Note all the "tabs" are at rest against the back bezel. Does yours look, more or less, like this? I'll bet that on yours, the first string raise is recessed in from the others a good bit.


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What you cannot see in the above picture is the slots in these tabs that engage in two guides in the back bezel. Below is a picture of a finger assembly out of a guitar.


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Here you can see the slots in the raise and lower tabs that fit into guides in the back bezel when the changer is assembled.

The problem you may be seeing is that you may have pulled the tab so far back when you "cranked it before installing the last stop" as you said, that you pulled the tab out of the track in the bezel. The "tab" may be resting against the bezel guide, but out of the slot.

If all this sounds plausible so far, try loosening that string a bit. Just tune it down a couple full steps or so. Don't take all the tension off. Next, push the tab back a little with a screwdriver and try and get that slot and guide re-aligned back together. I actually have experienced this once, which is why I'm suggesting this may resolve your problem.

Let me know if this works out for you or if I can improve on my description of the problem and solution. Good luck.

Mark :)

Posted: 6 Sep 2018 10:13 pm
by Lane Gray
Agreed.
When you say "after I put it back together," how far apart had you taken it?
If the stop bars (which are the top and bottom of the "window" inside the endplate) got moved, the scissor slots can scrape and bind.
If your lever has stops at both fully engaged and fully at rest, check to make sure that the stops are allowing the lever to release all tension at rest.
If the scissor doesn't hit the stop bar every time, the culprit should be revealed with some poking, prodding and observing.

Posted: 6 Sep 2018 10:38 pm
by Lane Gray
Good pics, good explanation.
The "back bezel" is what I was calling the "stop bar". On the Buds with that style of finger, the raise and lower stop bars are separate, and are part of the inner "frame * inside the window.
Regardless of the form of all-pull changer, it is vital that all scissors rest on the stop bar

Posted: 8 Sep 2018 11:25 am
by Garry Moore
I took another look and decided to loosen the barrels and pull the rods on the offending fingers and they went back to their neutral spot...albeit rather slowly. I think I still need to deep clean the changer as I poked around with a flashlight and could see tons of lint, hair and old grease all around the changer.

Thanks for taking time out to give advice. I really appreciate it.

Posted: 8 Sep 2018 3:24 pm
by Mark McCornack
Hi Garry,
Sure sounds like you may need to bite the bullet and give this a teardown & cleaning. It’s not a particularly challangibg task, bur there is a fair bit of tedium involved. Just log all your parts, where changes go, etc. Good luck! I’m sure you will be happy with the effort!
Mark :D

Posted: 9 Sep 2018 12:14 pm
by Lane Gray
Fortunately, you picked a system that is fairly easy to do that to, and fool-resistant if not fool-proof to reassemble.
From your description of the symptoms, you do need to do it. You can postpone the operation by flushing liberally with Triflow or the dupont equivalent, but it'll be happier playing after the teardown.

Posted: 9 Sep 2018 1:22 pm
by Garry Moore
Ok. Had a chance to get under it and see where I went wrong. I loosened and backed off the barrels that are on the RKL and RKR I added. They were so overtuned the rods wouldn't let the fingers return all the way back. Once I did that, I was able to reset the barrels to five turns open, tightened it and tuned it up.

Lane, when I bought this 6139 a few months back, I remember reading a few posts where mentioned a few times about overtuning but I was soaking in so much info on these things my eyes glazed over. Although maybe I'm stil confused about that. It's seems kinda like floating a Floyd Rose Trem.

I'm gonna rip it apart on my next day off and clean up the grunge on it. I haven't been able to stop playing it. Thanks again guys so much for your help.

In the meantime is this a good copedent for this thing? Emmons E9 on a Sho-Bud 3x4?
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Posted: 9 Sep 2018 7:36 pm
by Mark McCornack
Hi Garry,
Glad to hear you got it working and glad to hear you decided to do the tear down!

On the copedent, you’re showing a 3x5 configuration (including a vertical lever) but you said your guitar was 3x4?
Mine is a 3x4 and I have all the changes you show except for omitting the changes on strings 1&6 you show on RKR. The vertical lever for the B to Bd change I have on a knee. Otherwise, I use the other changes you show. This is just what I’ve personaly settled on, and by know means the “right way”. Works for me though. Good luck with the teardown!
Mark :D

Posted: 9 Sep 2018 7:45 pm
by Lane Gray
The all-pull isn't quite like the Floyd Rose floating tremolo, until either raises or lowers get overtuned.
The scissors (or bars on the old Buds) MUST rest on the stop bar until you pull them.
Rods must not be pulling them off the stop bar at rest.