Sho-Bud Super Pro parts Changer Flaw

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Bob Metzger
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Sho-Bud Super Pro parts Changer Flaw

Post by Bob Metzger »

I have a Sho-Bud Pro I, triple raise/double lower, Super Pro parts, late 70's. It's my favorite of my 4 Sho-Buds and I've had about 20 years of uninterrupted good service from this guitar. Lately, it developed some nagging problems that seemed to be getting worse. It seemed like the time to take the changer to bits and find out what's going on. I have limited experience taking apart changers. I've done it 4 or 5 times before.

We all know the pot metal Sho-Buds are both a blessing and a curse. We hate the pot metal and its dubious durability but we love the design, adjustability and playability of these steels. Well, I got the changer all apart. The triple raise/double lower changer fingers are 3-piece, the top-most piece, where the string crosses the roller/cam is pot metal. The other two pieces seem to be steel, all held together by two rivets. After cleaning and re-lubricating the changer fingers, I noticed a normally angled 'mickey mouse ear' part (about a 25~30% angle) that comes into contact with the lower part of the pot metal piece as the changer finger moves thru its motion. To me, the pot metal piece looks a bit like a sea horse and the 'ear' steel part contacts the backside of the sea horse tail (tough to describe without pics).

In a well-used Super Pro parts steel, eventually this steel ear will wear a groove into the pot metal where it contacts on the lower tail. As I said, I've played probably about 5000 gigs in the 20 years I've been using this steel - it's been in heavy rotation. The grooves dug into the pot metal tail varied from slightly deep to pretty deep, depending on the string involved. In the deepest ones, you could not manipulate the finger thru its entire motion without it hanging up (stopping/getting stuck) in this groove. In some cases, the ear part fell deep enough into this created groove that neither the string tension nor the return spring could pull it out. This limited the travel of the changer finger in question to about 2/3rds of its normal motion/range - I had found my problem. As you might guess, on an E9 tuning this phenomenon was most profound on strings 10, 8, 6, 5, and 4.

The real fix would be to replace the pot metal parts of the changer finger with ones made of a much more durable and harder metal and re-rivet this new piece onto all ten changer fingers. But is there a simpler fix that would work as permanently and allow the user to get the changer up and running quickly? For me, that turned out to be J-B Weld, an epoxy type substance. I've used it before with some success on repairing certain pot metal steel parts. Here, all I had to do was fill a very slight groove to flush with the J-B Weld epoxy on the pot metal tail (and then later, a little minor sanding). Time will tell if this will be durable enough to last decades, years or months. I think I'll add a heavier lubricant just to this area of contact with the 'ear' and the 'tail', maybe cam grease or vaseline as this is probably the greatest wear point of anywhere on this type of changer finger. For the rest of the finger lubrication (the rivet areas) I'll use Tri-Flow, gun oil, or a light machine oil.

I can't believe that I've never heard about this problem before in Sho-Buds using Super Pro parts; I guess I should be reading on the Forum more often - it has been mentioned in a few posts. For these Sho-Buds that have lots and lots of miles on them, this problem must occur time and time again. Has anyone with a well-used Super Pro parts Sho-Bud encountered these changer grooves worn in the pot metal changer fingers? If so, how did you resolve the problem? I'm very interested to hear your story and your method to find a fix and a positive result.

Thanks,

Bob M.
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Post by Storm Rosson »

:) The best way I have found(short of waitin on James M's new/upgraded fingers...eta unknown but James will let us know) is to substitute a finger that has the least wear for a finger with the most wear, typically a pedal or k/l with a rsise pull. The wear is from the little mouse eared angle onthe middle steel part as this is the Raise part of the changer and bears the most pressure/friction....Stormy , hope this helps :mrgreen:
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Post by Bob Metzger »

It's a good idea to sub in fingers with less wear on heavily trafficked changes like the Es and Bs in an E9 tuning. Yes, James Morehead will undoubtedly come up with the next great changer finger revision for us Super Pro parts guys. Until then, I'll monitor my little epoxy fix for durability and longevity and see how it all goes. It's an experiment that I thought was the least invasive thing to try. Thanks for your input.

Bob M.
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Peter den Hartogh
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Post by Peter den Hartogh »

In a previous post someone mentioned (Ricky Davis?) that you can change the angle of the mouse ear and let it scratch in a different place.
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Ricky Davis
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Post by Ricky Davis »

Thanks Peter; and that is true. I posted that idea some time ago and certainly a quick to moderate fix...but the problem of that fulcrom piece of what it's made out of; hanging down, will never go away...ha..
eventually in another 20 years of playing; it will wear another spot and bind up again; then you will HAVE to replace the finger. Or the idea Bob has of either expoxy a very hard but very thin surface there or if the JB weld hardens up enough to be the surface. Steel pushing on chromed pot metal; never makes a good combination..ha..that was the BAD executed idea part; on a great idea of a finger.
Shobud had a lot of great ideas; but poorly executed.
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Bo Legg
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Post by Bo Legg »

Since I don't lower my B, G# strings I spot welded all four of those fingers so there is no pivoting and therefore nothing to wear or cause problems.
I traded places with the low D string finger and the high E string finger since the D string finger was never used and in good shape.
I traded places with the low F# string finger and the low E string finger since the F# had not been used that much. I spot welded that finger I moved to the Low F# string since it only raised.
I also spot welded the high F# since it only raised.
It's like a new PSG and the A and B pedals are much easier and faster than they have ever been. They seem to be better about coming back to pitch when pedals are released.
I forgot to mention I traded places with the D# and high F# string fingers before I spot welded the now high F# finger.
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Stuart Legg
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Post by Stuart Legg »

Boy! Bo makes that sound so easy. He forgets about me having to listen to all the groaning and gripping while he was getting all those rods fastened back and readjusted.
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Post by Jim Pitman »

Cool Bo. You gotta admire a guy who optimizes his copedent with a welding torch. You could say you have a "triple braze" changer.

Rotating parts in general is a good idea too.
I do this every year with my pedals - 1 and 2 get used a lot more than the rest of course. Someday they will all look worn out.
Mike Cass

Post by Mike Cass »

the late John Coop had a nice fix for that problem: he installed a small roller in place of the bent flange and it solved the problem once and for all. Harry Jackson has been threatening to adopt that idea........
Bob Metzger
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Post by Bob Metzger »

I thought I would post a follow-up to my epoxy fix for the Sho-Bud changer fingers that developed grooves in the pot metal. Well, it's been over three years since I did my epoxy fix and all those nagging little problems from the finger getting hung up in the groove created by excessive wear continue to be gone and nonexistent. So, I have to say until a better changer finger is created for retrofit out of more durable material (get out your 3-D printers) this epoxy fix is more than adequate. I'm very happy with the fix and continue to be. It's fairly easy to do and seems to be a fairly almost-permanent cure. I'm hoping it'll last another 3 to 6 years and I'm betting it will.

Bob M.
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Ron Kassof
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Post by Ron Kassof »

That's great Bob. I had also wondered whether the pot metal could be plated (nickel?) in the contact area to prevent the notching.
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chris ivey
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Post by chris ivey »

why not just replace the fingers with new, then you're good for another 5000 gigs!??
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John Booth
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Post by John Booth »

Brother, if that guitar has worked for 5,000 shows, you've gotten a lot of love out of those fingers.
I agree, just replace the fingers and get another 5,000 shows out of it. She deserves the upgrade :)
JB
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Gene Haugh
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Post by Gene Haugh »

Hey Fellows;
I am so familiar with that problem and in the past with all the repair's we did at the factory I have seen all the above mentioned. The finger is chrome plated over the pot metal and when the lower bar rubs through the problem starts! The problem in my opinion is caused by the lower bar "STAMPING"! If you look at the edge of the lower bar that comes in contact with the chrome finger it is very rough and will act as a file or saw blade. "SO" what I have started to do on repairs I file the area on the lower bar smooth and as flat as I can side to side and then take it to the buffer and polish that area to a high smooth shine. It sure feels better to me and I think makes a bad situation better.

Bobbi Seymour showed me a small spring he said was suppose to be mounted around the finger where the contact area is but I never saw any other than the one he showed me. There is a little flat on the chrome finger where the spring was to go.
This is just My Two Cents worth.
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Ian Worley
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Post by Ian Worley »

Here's one with a nasty groove as described

Image

In most cases the steel scissor holds up much better than the pot metal finger, so it's usually not really necessary to replace the whole assembly, just the finger itself. I've milled a number of sets of these in 6061 or 2024 aluminum:

Image

Sho-bud used shoulder rivets to maintain free movement between the finger and the scissor. They're hard to come by in the correct size in small quantities, but with the proper tools (a lathe) one can fabricate some small 3/16" brass bushings for the shoulder and just use straight rivets, 9/64" if memory serves.
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Tony Prior
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Post by Tony Prior »

while I too recognize flaws in the materials, (not the design) this is also a good reminder that an Instrument should be properly maintained along it's 35 to 50 year journey .

Pulling the changer every 15 years or so for inspection and proper cleaning can do wonders for an instrument.

We should not be just adding goo (oil) on top of old goo.( oil) this is not just a musical instrument, it's a mechanical work of art.

Take it apart, clean , inspect, perform maintenance and journey on another 15 or 20 years.

My 74 Pro III gave up the ghost on two finger rivets around 1980 after 6 short years,two different fingers, who can say why. My 78 Pro I, new Super Pro design, looked like brand new upon disassembly last year, it was just dirty and had too much oil on the fingers.

I believe I took apart probably 8 different brand Steels over the last year or two,( older Instruments) each had something that needed attention which would not have been discovered had I not taken them apart.

Bottom line ( my opinion of course) sitting behind an instrument that is several decades old that has never been apart for cleaning, inspection and perhaps slight repairs will probably talk to you in the action/play-ability dept. If and when you do, when you put it back together you will notice and feel the results in a NY minute.

Someone above mentions years of gigs on the Steel in question, yeah I hate to read it needs a repair but I am not surprised ! The only way you can add a few of the latest design components by whoever we get them from is to first " take it apart".
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Whose got Super Pro parts Changer Fingers for sale?

Post by Bob Metzger »

Hey, I would love to buy a few extra changer fingers for my steel. Who is selling the Super Pro parts changer fingers? Actually, there are two types of Super Pro changer fingers. The one I describe in the above thread is 'Type 1' and is the earlier, first type. 'Type 2' can be differentiated by a large triangle metal piece toward the bottom of the finger, so they are visually different but both pot metal on top. In my experience, I prefer the Type 1 changer finger. Type 2 is good but not capable of the liquidy feel of the Type 1 finger. I have Sho-Bud steels that have both of these changer fingers but my observations I would have to say are probably anecdotal.

If anyone has got any used Type 1 changer fingers (with the grooves in the tail) that they are not using or removed from their steel, I'm happy to take them off your hands!

Bob M.
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Ian Worley
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Post by Ian Worley »

The difference is only in the lower scissor arm return spring mount point, it's offset on the later version. The bottom supports and comb-shaped stop are offset further towards the center of the guitar as well. The casting is slightly different between the earlier and later finger versions at the raise helper spring attachment nub. The pivot geometry between the finger and scissor however is identical.

The difference in "liquidy feel" you describe is likely attributable to tighter/looser return springs, or something else like lubrication, friction or the relative looseness/tightness of fit, not the difference in design.

The 2/2 fingers they used around ~'76 are basically the same as the earlier 3/2 also.

Image
Image
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John Billings
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Post by John Billings »

Hi Bob!
I'm sure James will be calling me in a day or two when he gets back home. I'll mention your problem to him. He got a lot of parts after Coop passed.
Best,
JB
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Post by Bob Metzger »

Hey JB,

Hope you're doing well. Maybe I'll stop by in August when Bret Favre gets inducted in Canton!

Best,

Bob M.
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John Billings
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Post by John Billings »

Bob, I'll take you to meet Dr. Z. You can try out his Surgical Steel amp. I already have one, but it's a bit different from the stock model.
As always, Best,
JB
I can't play right now. Tore up both rotator cuffs!
Dr. Z Surgical Steel amp, amazing!
"74 Bud S-10 3&6
'73 Bud S-10 3&5(under construction)
'63 Fingertip S-10, at James awaiting 6 knees
'57 Strat, LP Blue
'91 Tele with 60's Maple neck
Dozen more guitars!
Dozens of amps, but SF Quad reverb, Rick Johnson cabs. JBL 15, '64 Vibroverb for at home.
'52 and '56 Pro Amps
Bob Metzger
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Post by Bob Metzger »

JB,

I've reading your posts about that amp! It sure sounds like another winner. I've never heard a Dr. Z I didn't like alot. Hey, get well soon and layoff that curveball.

Bob M.
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Tony Prior
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Post by Tony Prior »

It does appear that Sho Bud recognized the issue and made a change on the spring point on the lower finger.

I have an '81 ish (17492) Pro I with the "MOVED " spring point on the lower finger. ( latest style) .

I also have a mid 80's Super Pro which indeed has the later style with the "moved" spring point.

Can anyone say when the change was made ?
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Ian Worley
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Post by Ian Worley »

The only reason I am aware of for the change (the larger offset in the lower return spring mount) was to accommodate the tighter spacing on the Super Pro vs. earlier Pro II/III models. I don't think it had anything to do with the issue described by the OP. The pivot geometry and counteracting forces applied are the same for both designs, and the pot metal fingers had only been around for four or five years at that point anyway, so it's unlikely it was seen as much of an issue yet.

The Super Pro changer is much closer to, and sort of integrated with, the end plate. The greater offset was necessary to allow enough space for the appropriate length lower return springs. On the later Pro I/II/IIIs that used these fingers, the bottom "L" support pillars that the lower return spring support mounts to were moved inward to compensate.

If you look under both your Pro I and Super Pro you'll see the difference in where the fixed ends of the lower return springs are relative the end plate. The Pro I will have a gap (coincidentally about the same width as the offset between the two styles) ;-)

The earlier 3/2 (and 2/2) fingers with the narrow lower scissor were used on Pro series guitars ~'76-'78-ish. I've never seen them in a Super Pro, but with Sho-Bud, who knows.
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Tony Prior
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Post by Tony Prior »

Thx Ian, that makes sense.
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