Blade Wobble: What do you think?

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Have a question: what's the safest way of improving it on a double blade single spring knife? The Master blade has it, the Minor doesn't.

Thanks, Will

 

Weather it’s new or old,blade play drives me nuts.

 

That a problem that I run into a lot. That blade play is sometimes caused a liner that has a burr in it, or a blade who's pivot hole wasn't drilled perfectly perpindicular. I tighten a lot of scout knives, so there's always a second blade to deal with. When one of these issues comes up, it's gone beyond my abilities to fix perfectly.

But for basic tightening of the joints, I mount the knive's bolsters in a small hobby sized c-clamp, with a piece of leather wrapped around the bolsters. Then I tighten the clamp a bit, over and over, frequently checking the blade play between squeezes.

If I go a hair too far, and one of the blades gets too tight, I can just give it some lateral pressure to loosen it back up. As logn as the pin hasn't been peened yet, it's pretty easy to loosen things back up.

Once the knife is the best I can get it, there is usually a bit of pivot pin sticking out away from each bolster. I peen the pin on both sides with a ball peen hammer, the knife laying on an old wooden cutting board. Then I sand the bolster down smooth with wet/dry paper.

 

Wow. I totally read that wrong. For a single spring knife, just tighten the one end with the blade play. Simple as that.

 

It seems like scout patterns always have blade play. 4 blades on two springs just asks for blade play, it seems. Scout knives often weren't all that well finished either, since they were going to kids. So probably 2/3 of the old scouts I buy need some adjustment. Either joint tightening or blade crinking, or both. I always tighten first, and crink later, since the tightening often affects the crinking.

What I'm not sure about is scout knives with a fixed bail. I assume that the bail is also the pivot pin. Does anybody know if that's correct? I never really mess with that end, as I'm usually only concerned with play in the spear blade.

 

No, there is no drag. The liner tip is only bent over enough to take up the minute space that allows the blade wobble. Besides, brass is soft and not tough enough to cause wear on the tang of the blade.

 

I guess my lucky streak ended...received a new knife with lateral play this morning.
(I checked because opening it seemed easier than expected)

 

That's correct on the GEC #98. Mine doesn't have any blade play.

 

Thanks for the tips about correcting it. I was a bit leery of doing it to a double end single spring knife in case it messed up the the secondary blade too...

Put it in a vice with leather padding, applied careful pressure-got to watch the scales ....tightened it up OK, snap not as good and the pivot protruded. Paper and buffing smoothed it down but still totally visible, don't mind too much as it's a user but I'd be uneasy about a more showy knife looking like it. Could be my lack of experience though

 

You did right in squeezing the bolsters together. Snap will definitely take a hit if you squeeze too far. Just apply some lateral pressure to the blade to open it back up a smidge.

Once you’ve gotten the wobble out, and the play is still acceptable to you, it’s time to peen the pivot pin. If you just sand down the pin, it will work itself loose again in short order. So take a ball peen hammer and peen the pin. Tap away with the ball end of a good sized hammer. You need a squash the end of the pin to fill the hole in the end of the bolster. This is what keeps the knife from separating again.

Peening will leave dimples in the end of the pin, and where you miss on the bolsters, but that’s okay. After the pin if peened, use wet dry paper to remove the dimples and the protruding pin. I start off with a low grit, like 200, and work my way up to around 800 for a brushed finish. Sometimes I’ll go as high as 2000 grit and buff with simichrome polish afterward.

Pro Tip: If you glue a piece of 200 grit paper to a mouse pad, aligning the edges together, you can lay the knife down on the paper/pad and align the edge of the bolster with the paper/pad. Then rub back and forth keeping the edges aligned. The pad will allow the paper to bend and conform to the shape of the bolster a bit.

 

Jeff my friend - and to all who have posted already.......
I really do not like side to side movement in a blade - Especially new.
In an old Knife- I can only accept minimal play - as in slight- otherwise I just don’t want it.

It’s funny - I went to the Queen show in 2016 also attending the GEC Rendezvous of course, at the Queen show there is a well known Seller who had quite the display of older + Antique Knives.
I saw a knife that really took my interest- asked him if I could handle the Knife etc- lovely Knife- Lots Of Blade play - he said to me “ you seemed to like the knife - but not now?” - I replied that it’s a very nice knife but no thanks- he pressed me further in quite a way where I thought ok..., so I told him that the blade play is severe - ..... well off he went into a rant....
“ who started all this Blade Play talk - it’s all [email protected]?* - there’s no such thing etc etc etc - I said to him that that Using a knife with blade play when cutting something in a straight line is impossible- the knife is all over the place!”
I walked away from the Guy thinking - yeah - that’s the very first thing you would check to low ball some poor guy out of his knife then sell it tenfold as a beauty

I voted A1 B3

 

@Buzzbait Thanks for the guidance, much appreciated. Only have a small peening hammer but I think it will do.

Regards, Will

P.S. Worked out very well, the dents from the ball hammer soon vanished with paper, then strop loaded with compound. Walk & talk back where they were but no play

 

Thanks for posting on the squeeze and peen @Buzzbait . Only issue I had with the Kershaw Rhinelander I just picked up was blade wobble when locked. Fixed it right up, but still smooth enough to open and close with one hand. I used a portable tabletop rubber jawed vise I have. Was perfect for this, no leather strips needed. Thanks again for the tip.

 

Bravo!!! Well done.

 

Kudos are all yours, sir. A rhesus monkey with a lobotomy (raises hand) can turn a vise, I just needed the knowledge. It was aggravating, because the knife was ALMOST perfect! I'm sure there are others that know that feeling. My BP is probably down 10 points

 

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I missed this poll, but blade wobble is unacceptable to me. If there's perceptible wobble, the knife either goes back or goes back on eBay describing the situation. I find new Case Saddlehorns for whatever reason almost always seem to have blade wobble. I've had 5 of them, and only own 1 of them, so a 80% failure rate means enough of that pattern for me.