Check your pivots and let me know.......

[Gerhard Gerber]

I may have mentioned how much I like Pete at Cedric & Ada Outdoors on YT, his tests and sense of humor is very my to my taste.

He recently shouted out another channel, and I'm hooked: Super Steel Steve.  Being a potty mouth myself, I do not mind his potty mouth, but be warned he doesn't hold back.

That said, his tests, results and insights are fascinating!

All this is just a preface to give credit where credit is due, he mentioned this in a video........

Please try several of your knives and check for yourself.......

Disengage the (whatever) lock and close the knife to about halfstop, keeping the lock disengaged feel for blade play.

Out of my knives I've checked so far the Pacific Salt is the worst, I honestly don't understand what is happening because lock-up when open is rock solid, but at halfstop with the lock held down the blade is literally flopping around.

[Aloha]

What is the reasoning for determining blade play in this situation? 

[SteveC]

^ Also what kind of lock ?

[Aloha]

If I am understanding this correctly.  I just checked my Spyderco Native and its solid and solid when locked.    My Delica is also solid and solid when locked.  My Kershaw Dimension is ROCK solid very slight when locked.  My Skeletool CX very slight yet when locked solid.  My Drangon Fly 2 ROCK solid and when locked solid.  My Buck 110 cir 78'-79' slight movement, there is some movement when locked as well. 

 

[pfrsantos]

I'd say it only matters when you have your blade locked, 'cause that's how you'll use it.

 

[Nix]

What is the reasoning for determining blade play in this situation?

I had the same question...... 

[Dean51]

What is the reasoning for determining blade play in this situation?

 

I'd say it only matters when you have your blade locked, 'cause that's how you'll use it.

 

 

  and can't think of anything else to add.

[hiraethus]

If there's play in the pivot when the knife isn't locked then you're applying forces through the lock mechanism unnecessarily when it is locked.  You want the large diameter, sturdy pivot to do most of the work, and the lock to only have to prevent the knife from closing.

[Old Boy]

If there's play in the pivot when the knife isn't locked then you're applying forces through the lock mechanism unnecessarily when it is locked.  You want the large diameter, sturdy pivot to do most of the work, and the lock to only have to prevent the knife from closing.

Great insight, do we know if that constitutes a major or critical failure?

Im thinking no as I have a buck knife that has play when locked. Never had an issue and inherent in Backlock and peen design. And technically you would rarely use a knife half open (though I’m guilty of doing that on occasion - laziness or just hiding it from people). So I am thinking that defect is more a statement on the overall design and quality?

Just asking, no disrespect intended. Genuinely curious and want to separate functionality vs. nitpicking.

By the way my cold Steel America’s Lawman, spydiechef, and Skeletool has slight bladeplay at half stop ever so slightly. It’s interesting, just lubed it last night so you can hear the oil squishing. Solid lock up except for the Skeletool which I expected.

[cody6268]

Just those sitting on my desk.

Gerber Magnum LST Jr. (1990s?). None whatsoever.  Same with its modern successor, the US-1.

Remington R-131 Small Trapper: none. Pretty good for something that comes from Bear and Sons.

Buck 110LT "Shield". Slight when fully open and locked. But the 110 LT is a budget offering.

Winchester (CHINA) Small Stockman, none.

Case 6488 Large Congress (1976). Slight wobble, but is a well-used knife, so expected.

And my pocket.

Eye Witness Lambsfoot; some, but again, is a well used knife.

Spyderco Ladybug Salt Hawkbill: increasingly more than when new. Really ought to tighten its pivot up; but don't think I have a Torx that small.

Most of the tools on my Tough Tool have a hint of play.

[CallsignBadger]

My benchmades generally have a wee bit of wiggle, but are rather good

[Aloha]

If there's play in the pivot when the knife isn't locked then you're applying forces through the lock mechanism unnecessarily when it is locked.  You want the large diameter, sturdy pivot to do most of the work, and the lock to only have to prevent the knife from closing.

This is true for all locking mechanisms?  Could there be other factors for blade play?  My Tenacious liner lock was rock solid both locked and checking as explained.  This is very interesting.     

[Gerhard Gerber]

What is the reasoning for determining blade play in this situation?

IIRC his reasoning was it doesn't matter.....just something he mentioned that struck me

[Gerhard Gerber]

^ Also what kind of lock ?

Lock should be disengaged when testing so it shouldn't matter.......it's not about lock type.

[Gerhard Gerber]

If there's play in the pivot when the knife isn't locked then you're applying forces through the lock mechanism unnecessarily when it is locked.  You want the large diameter, sturdy pivot to do most of the work, and the lock to only have to prevent the knife from closing.

 

Exactly.

My Salt 1 has lock rock which I understand, but the Pacific is really strange: no blade play, solid lock-up.  The play at halfstop comes from the pivot moving in the pivot collar it seems.......don't love that 

My Para3 is tight, same with the Skyline.

[hiraethus]

This is true for all locking mechanisms?  Could there be other factors for blade play?  My Tenacious liner lock was rock solid both locked and checking as explained.  This is very interesting.     

Probably...  A back lock won't stop side-to-side play in a blade as it only applies a force perpendicular to the blade pivot axis.  A liner or frame lock will take up some side-to-side play as it  applies a locking force at a slight angle, so has both radial and axial components.  I don't have any experience with other lock types, but I expect that most of them behave in a similar way to a liner lock in that they apply both radial and axial locking forces.

You need some clearance in the assembly for the blade to open and close.  Not enough = friction/rough action.  Too much = play/slop.  The excess clearance could be between the pivot and blade hole (or bushing) or it could be between the tang and liners/frame.  Or both if it's really smurfly made.

My Sebenza has a tiny amount (a fraction of a mm) of side to side blade play if I hold the lockbar off the tang while opening - but the blade has a nice smooth action.  This goes away entirely when locked open.

[hiraethus]

Great insight, do we know if that constitutes a major or critical failure?

Or it might be no issue at all.   For example, in a liner lock a sloppy pivot could increase the rate at which the lock face wears.

So I am thinking that defect is more a statement on the overall design and quality?

I would say so.

I have a Leatherman Charge TTi that has no play in the longer outside tools while opening, but does have play in the blades when locked open.

[Aloha]

This is true for all locking mechanisms?  Could there be other factors for blade play?  My Tenacious liner lock was rock solid both locked and checking as explained.  This is very interesting.     

Probably...  A back lock won't stop side-to-side play in a blade as it only applies a force perpendicular to the blade pivot axis.  A liner or frame lock will take up some side-to-side play as it  applies a locking force at a slight angle, so has both radial and axial components.  I don't have any experience with other lock types, but I expect that most of them behave in a similar way to a liner lock in that they apply both radial and axial locking forces.

You need some clearance in the assembly for the blade to open and close.  Not enough = friction/rough action.  Too much = play/slop.  The excess clearance could be between the pivot and blade hole (or bushing) or it could be between the tang and liners/frame.  Or both if it's really smurfly made.

My Sebenza has a tiny amount (a fraction of a mm) of side to side blade play if I hold the lockbar off the tang while opening - but the blade has a nice smooth action.  This goes away entirely when locked open.

Thank you.  Always something neat to think about. 

[Aloha]

What is the reasoning for determining blade play in this situation?

IIRC his reasoning was it doesn't matter.....just something he mentioned that struck me

 

[Gerhard Gerber]

I adjusted the slop out of my Pac by tightening the pivot.....lubricated and it's almost acceptable opening and closing 

....as opposed to a pleasure. 

[Old Boy]

Great insight, do we know if that constitutes a major or critical failure?

Or it might be no issue at all.   For example, in a liner lock a sloppy pivot could increase the rate at which the lock face wears.

So I am thinking that defect is more a statement on the overall design and quality?

I would say so.

I have a Leatherman Charge TTi that has no play in the longer outside tools while opening, but does have play in the blades when locked open.

Thanks!! Whew I can sleep now 😜