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Topic: fingers/ rivets |
Steven Welborn
From:
Ojai,CA USA
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Posted 3 Aug 2010 3:13 pm |
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I notice a little play/looseness where the cam(s) or top finger component is joined to the lowering scissor plate (old BMI in this case). dont know how snug these are when new. Naturally they need to swivel freely but if these tend to loosen up with time and use, I'd think the least slop the better for string energy transfer. Is this area of maintenance addressed out there...resetting the rivets with the right punch or tool? the truth is out there -i know  |
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Danny Letz
From:
Old Glory,Texas, USA 79540
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Posted 4 Aug 2010 3:59 pm
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| I went thru a BMI a year or two ago and I did try to tighten the rivets. I was mostly successful, but one tap two much and you've locked it down. Be carefull. |
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Bent Romnes
From:
London,Ontario, Canada
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Posted 4 Aug 2010 5:33 pm
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I discovered a nice way to get the rivets just tight enough: mushroom the rivet so that things are a bit too tight. Then, with the rivet head floating, put a center punch in the middle of the flare and tap lightly till you have loosened up the scissors just enough to swivel freely.
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BenRom Pedal Steel Guitars
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Andy Sandoval
From:
Bakersfield, California, USA
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Posted 4 Aug 2010 5:44 pm
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| How about slippin some kind of metal shim under the rivet head then tap the rivet till it's tight on the shim then pull the shim out. |
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Allan Munro
From:
Pennsylvania, USA and Scotland
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Posted 4 Aug 2010 7:43 pm
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| Andy Sandoval wrote: |
| How about slippin some kind of metal shim under the rivet head then tap the rivet till it's tight on the shim then pull the shim out. |
Yes, I did something like that on a couple of changer fingers I made from scratch. Worked like a charm. I made the shims by cutting up a soda can. (Mountain Dew if you care about the flavor of your shim!) It actually works better of you put the shim between the components of the assembly rather than directly under the rivet head.
Regards, Allan.....
_________________
Only nuts eat squirrels.
Television is the REAL opiate of the masses! |
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Bent Romnes
From:
London,Ontario, Canada
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Allan Munro
From:
Pennsylvania, USA and Scotland
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Posted 5 Aug 2010 6:25 am WARNING - facetious post within!
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| Bent Romnes wrote: |
More'n one way to skin a cat fer sure  |
Take care there Bent! You will have the Archie/Bamma posse after yer blood if you post stuff about cat skinnin' DYK... 
_________________
Only nuts eat squirrels.
Television is the REAL opiate of the masses! |
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Jim Bob Sedgwick
From:
Clinton, Missouri USA
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Posted 5 Aug 2010 7:33 am Rivet
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| You could also place the finger in a vise and "carefully" tighten the rivet. Again be VERY careful. Allan's solution might be a little safer. I have used the above method and it does work. |
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John Billings
From:
Ohio, USA
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Posted 5 Aug 2010 7:39 am
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| I've put hundreds and hundreds of those together. I used a small, light, ball peen hammer. Not the ball side but the flat side. |
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Bent Romnes
From:
London,Ontario, Canada
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Posted 5 Aug 2010 9:04 am
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John, obviously experience hath spoken. When you get the feel for it thru 100's and 100's of assemblies, well, then you get the feel for it, what can I say.
I have put together a total of 30 and I did find it tricky. Too tight and I'd have to drill out the old and try again with a new rivet. The way I described it above, was given to me by Martin Weenick. I saw the wisdom in his procedure, for a beginner that is.
Of course this leads to more questions...Is there a hand-operated rivet setter for regular rivets? I saw one that they put together chainsaw chains with..mighty slick!
Another idea I would like to try, this one is also from Martin: Chicago screws. Cut to required length. Put a drop of red loctite on the threads, tighten up to required tightness and wait for it to set. What do you think John?
_________________
BenRom Pedal Steel Guitars
https://www.facebook.com/groups/212050572323614/ |
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John Billings
From:
Ohio, USA
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Posted 5 Aug 2010 9:24 am
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Interesting thought Bent! But,,, you know, scissors are really thin gauge metal. You'd get maybe two threads of a really short screw to grab, and not much surface for the Loctite to grab onto. And, you have a threaded surface reacting with the other piece of the scissors. Might be a lot of wear compared to a smooth rivet.
I found that 4 hits with that little hammer was about right. Just put the assembly on a steel block and tapped away, checking my progress as I went. You just got a feel for it. By checking after every tap, you could tell when you were getting close, and would reduce the force of the next tap accordingly. Also, they don't have to be really very tight, some play in that connection is necessary for smooth action. We used those hollow tipped rivets, not solid ones. Probably from McMaster Carr.
"checking my progress as I went" is probably my best advice. |
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John Billings
From:
Ohio, USA
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Posted 5 Aug 2010 9:48 am
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Bent,
Here are the type of rivets we used, only these are large, ours were tiny and sized for the job.
http://www.mcmaster.com/#tubular-rivets/=89v6it
Click on the pic of semi tubular rivets.
Note the drawing showing the "Internal Hole Depth." The walls of the hole are what get peened over. The remainder of the rivet, from the end depth of the hole to the bottom of the rivet head was the thickness of the two parts of the scissors combined. So, if the two parts combined gave a thickness of 1/8", that was the length of the rivet from the bottom of it's head to the end of the tubular hole in the rivet.
Gosh! That sounds confusing. Maybe I should have just drawn a picture! |
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Bent Romnes
From:
London,Ontario, Canada
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Posted 5 Aug 2010 9:51 am
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John, advice taken and noted. I am here to learn. Just a matter of keeping my eyes and ears open and I'll learn lots.
Thanks John!
_________________
BenRom Pedal Steel Guitars
https://www.facebook.com/groups/212050572323614/ |
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John Billings
From:
Ohio, USA
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Posted 5 Aug 2010 10:46 am
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Lousy drawing, and poor pic of the semi-tubular rivets;
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Leon Campbell
From:
Texas, USA
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Posted 5 Aug 2010 12:56 pm revets
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| Hey John, what do you brad the rivet with? can you buy a hand tool to do the job? thanks, Leon |
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John Billings
From:
Ohio, USA
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Posted 5 Aug 2010 1:07 pm
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LC,
Brading a rivet is not a term I've heard before! The only tool I used to peen over the end of the semi-tubular rivets was a small ball peen hammer. I used the flat face of the hammer head. The hammer was about 7"/8" long, with a metal handle. The head was quite light. What is bradding a rivet? |
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Lamar Colvin
From:
Havana, Florida, USA
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Posted 5 Aug 2010 3:53 pm
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| A hand "rivet clincher" can be purchased from McMaster-Carr For about $35.00 |
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Bent Romnes
From:
London,Ontario, Canada
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John Billings
From:
Ohio, USA
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Posted 6 Aug 2010 5:29 am
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| Does it clinch the rivets tight? Can it be adjusted to let them be loose? If not, it wouldn't be that useful. I could complete a single scissor mechanism, and rivet it in less than a minute, and assemble the parts, scissors, fingers and shim washers between all parts onto a changer axle,in about 20 minutes or less. And that includes the less than ten minutes to rivet the scissors together. I guess that's why I see a "clincher" or other device as overkill for a very simple operation. |
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Bent Romnes
From:
London,Ontario, Canada
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Posted 6 Aug 2010 5:57 am
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John, I can see the logic in your argument. The onlything I need to keep in mind is to practice and get good with the hammer.
That is fine..for the raise and lower plates. Now to the finger itself. There, I might want to bore a stepped hole so that I can use a semi-hollow shoulder rivet so that I can let the finger run freely on the shoulder part. Because of space concerns between each finger, the tubular part gets flared inside the 2nd part of the hole. There I would need a setting tool of some sort. I improvised by grinding a punch to approximate shape. But still I found I had very little control. Here, in particular is where Martin's idea came in handy; where I would flare the rivet just a bit too tight, then loosen it again by tapping inside the tube bottom with a center punch until it loosened just enough. Geez that sounds messy. I draw even messier 
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BenRom Pedal Steel Guitars
https://www.facebook.com/groups/212050572323614/ |
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John Billings
From:
Ohio, USA
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Posted 6 Aug 2010 9:18 am
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LC,
is this the clincher? Should be easy for Bent to just make one.
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