Measured OTF blade slop?

[mcflyfyter]

I know that few people use an OTF for anything approaching hard use, but I have always wondered how much they loosen up with use. Sure you can nail your ultratech through a 2x4 and the blade will still function, but there seems no way that it is still as tight as new. How does use actually effect the knife, and how much effect does it have over time?

I am thinking about putting a dial indicator on a new OTF and monitoring slop over time. Maybe just light use and a boatload of cycles for a week or 2 to simulate common usage, then measuring every so often once its broken in and in full use?

Assuming nobody has actually done this, (let me know if it has) would anyone else even care about these results?

 

[K.O.D.]

While I am definitely not a hard user, my Manticore E has firing issues now that it is a few years old. I haven't noticed any appreciable "slop" actually it seems about the same in the two years I've owned it. It is my most used and carried OTF. I keep meaning to send it in for warranty, but always forget.

I think that wear from the action of opening and closing will cause issues with alignment/movement more than cutting will.

I've had my Hogue Exploit for 2.5 years, and the movement/slop is exactly the same as new, as is my Brian Tighe small Twist Tighe. No firing issues with either of them either.

 

[mcflyfyter]

While I am definitely not a hard user, my Manticore E has firing issues now that it is a few years old. I haven't noticed any appreciable "slop" actually it seems about the same in the two years I've owned it. It is my most used and carried OTF. I keep meaning to send it in for warranty, but always forget.

I think that wear from the action of opening and closing will cause issues with alignment/movement more than cutting will.

I've had my Hogue Exploit for 2.5 years, and the movement/slop is exactly the same as new, as is my Brian Tighe small Twist Tighe. No firing issues with either of them either.

I'm curious how you are so confident that you can measure play by feel years later. I once handed a shim to a machinist with 35 years experience and asked him how thick. He felt it and thought for a bit and said 15. It was an 8 thou shim.

 

[K.O.D.]

I'm curious how you are so confident that you can measure play by feel years later. I once handed a shim to a machinist with 35 years experience and asked him how thick. He felt it and thought for a bit and said 15. It was an 8 thou shim.

To be honest, I rotate 25 knives. I also have an unfair advantage. I've been partially blind since I was 11, and my other senses are very, very heightened. I can tell little things like that. I check all my knives for play and other wear related issues at least a few times a week, if not every day.

 

[mcflyfyter]

To be honest, I rotate 25 knives. I also have an unfair advantage. I've been partially blind since I was 11, and my other senses are very, very heightened. I can tell little things like that. I check all my knives for play and other wear related issues at least a few times a week, if not every day.

How much play do your OTF's have?

 

[The Aflac Duck]

While I am definitely not a hard user, my Manticore E has firing issues now that it is a few years old. I haven't noticed any appreciable "slop" actually it seems about the same in the two years I've owned it. It is my most used and carried OTF. I keep meaning to send it in for warranty, but always forget.

Hose it out with WD40. Probably dirty inside and the locking sears are moving too slow to engage.

 

[K.O.D.]

How much play do your OTF's have?

All three have very slight downward play (as in if you push on the spine they move down slightly). No horizontal play.

Hose it out with WD40. Probably dirty inside and the locking sears are moving too slow to engage.

It is unreliable, but yeah I'll spray some WD in there tonight and see if that helps. Sometimes it fires, sometimes it partially fires or partially retracts.

 

[The Aflac Duck]

yIt is unreliable, but yeah I'll spray some WD in there tonight and see if that helps. Sometimes it fires, sometimes it partially fires or partially retracts.

Spray it and drain it a few times, when it’s full with WD, shake it up to jostle around any dust inside. Then after flushing, leave it tip down on a paper towel overnight. If that doesn’t do the trick, you’ll either have to disassemble it or just send it in. If there’s something stuck inside that is really stubborn it needs to be opened up.

Regarding the OP’s question, I think this is a bit too worrisome. If you need a knife for “hard use” then get a fixed blade. I’m sure an OTF may loosen up over time from regular tasks and wear and tear, but not to the point where you’d actually notice. If the blade was loose enough inside, the edge would drag on the inside of the body causing it to dull on its own. I have yet to wear an OTF out to that point, and I basically only carry autos.

 

[mcflyfyter]

.Regarding the OP’s question, I think this is a bit too worrisome. If you need a knife for “hard use” then get a fixed blade. I’m sure an OTF may loosen up over time from regular tasks and wear and tear, but not to the point where you’d actually notice. If the blade was loose enough inside, the edge would drag on the inside of the body causing it to dull on its own. I have yet to wear an OTF out to that point, and I basically only carry autos.

I'm not sure why it would be more "worrisome" than testing super steel A vs super steel B, but that type of thing is worried about excessively here.

An OTF blade touches the handle in very different spots while in use vs when firing/retracting. If the chassis is worn and sloppy from deployed use, the blade would actually be less likely to rub because the track that guides the blade would remain tight. The sloppy end would actually give the blade more clearance.

I may be overly curious by monitoring change. I have thermometers in all my refrigerators and freezers, I calibrate my scales, and I even hand calculate fuel milage occasionally. Heck, I've even gone to see the doctor a few times even though I wasn't sick.

 

[The Aflac Duck]

I'm not sure why it would be more "worrisome" than testing super steel A vs super steel B, but that type of thing is worried about excessively here.

An OTF blade touches the handle in very different spots while in use vs when firing/retracting. If the chassis is worn and sloppy from deployed use, the blade would actually be less likely to rub because the track that guides the blade would remain tight. The sloppy end would actually give the blade more clearance.

I may be overly curious by monitoring change. I have thermometers in all my refrigerators and freezers, I calibrate my scales, and I even hand calculate fuel milage occasionally. Heck, I've even gone to see the doctor a few times even though I wasn't sick.

I’m not worried about bladesteel, some are like me and don’t get too caught up in those things. Some do, some don’t. There’s no right or wrong way to go about it.

The part of the OTF blade that touches the inside of the handle (when made properly) is the tang. If you’ve ever taken one apart you can see the path that it glides along. If that path below the rear sear is worn from deployment, the edge might touch. If the path above the front sear is worn from use, yes it will have more slop to it.

Like I said, under normal use any differences in tolerance would be minimal. I have a lot of OTFs and have been carrying and taking them apart for years.

 

[mcflyfyter]

I’m not worried about bladesteel, some are like me and don’t get too caught up in those things. Some do, some don’t. There’s no right or wrong way to go about it.

The part of the OTF blade that touches the inside of the handle (when made properly) is the tang. If you’ve ever taken one apart you can see the path that it glides along. If that path below the rear sear is worn from deployment, the edge might touch. If the path above the front sear is worn from use, yes it will have more slop to it.

Like I said, under normal use any differences in tolerance would be minimal. I have a lot of OTFs and have been carrying and taking them apart for years.

My Contego lasted 5 and a half years, and I just can't imagine any OTF is going to last that long. Maybe they will, I've been wrong before.

I just find it odd that nobody actually measures blade play. I get that it is inherent in the design, but a steel peg in an aluminum hole is going to wear. The standard for an OTF seems to be "It still fires." Many worn out folders still open, but we aren't scared to say it is worn. Then you get the subjective guesses like "good as new" or "very slight play."

 

[Steely_Gunz]

I think the limiting factor is that that wear/time is going to be subjective and beyond saying "Yep, she developed 3mm of slop in 5 years of carry" isn't empirically driven beyond the fact that you have noticed blade play in a knife you have carried and used.

The number of cuts, the material cut, and the force exerted on the blade are important factors. I could use a crappy Cobra to do nothing but snick open once a day and open 3 envelopes and it be the same level of crapiness in a decade's time. I could take a Combat Troodon and use it to whittle little tobacco pipes for all the underprivileged children out of seasoned oak and it would probably start to show wear and play within months as I stress the aluminum.

I get the idea of wanting to know, but it would take some serious measure and documentation of how the knife was used to make it valid data. One of the issues many had with the tests Cliff Stamp did (RIP) was the fact that he graphed "half strength chops" as data points. It looked neat in a graph but it was anecdotal at beat.

He's my admittedly snobby take:

OTF autos have blade play, and are generally NOT used hard. Despite the marketing, I would not take a Combat Troodon as my "going to war" knife. I think they are very well made knives that will take way more abuse than what many think they will. That is to say, while I would not want to be dropped on a desert island with a Microtech, many would most likely be surprised how many coconuts I could hammer it through.

The fact of the matter is that you carry an auto because you like it. You use however you see fit. If it devolpes play from hard use, send it back for a spa treatment or just buy a new one. You have already dropped $500 on a fidget, so it's not going to kill you do it again. This is coming from a guy who will only carry an OTF unless he is legally forced to leave it at home. I adore them. I feel naked without my CT. There isn't a knife that I feel strikes that balance between aesthetic and performance and style. However, if I manage to wear one out, it's just yet another excuse to buy something new

 

[mcflyfyter]

I think the limiting factor is that that wear/time is going to be subjective and beyond saying "Yep, she developed 3mm of slop in 5 years of carry" isn't empirically driven beyond the fact that you have noticed blade play in a knife you have carried and used.

The number of cuts, the material cut, and the force exerted on the blade are important factors. I could use a crappy Cobra to do nothing but snick open once a day and open 3 envelopes and it be the same level of crapiness in a decade's time. I could take a Combat Troodon and use it to whittle little tobacco pipes for all the underprivileged children out of seasoned oak and it would probably start to show wear and play within months as I stress the aluminum.

I get the idea of wanting to know, but it would take some serious measure and documentation of how the knife was used to make it valid data. One of the issues many had with the tests Cliff Stamp did (RIP) was the fact that he graphed "half strength chops" as data points. It looked neat in a graph but it was anecdotal at beat.

He's my admittedly snobby take:

OTF autos have blade play, and are generally NOT used hard. Despite the marketing, I would not take a Combat Troodon as my "going to war" knife. I think they are very well made knives that will take way more abuse than what many think they will. That is to say, while I would not want to be dropped on a desert island with a Microtech, many would most likely be surprised how many coconuts I could hammer it through.

The fact of the matter is that you carry an auto because you like it. You use however you see fit. If it devolpes play from hard use, send it back for a spa treatment or just buy a new one. You have already dropped $500 on a fidget, so it's not going to kill you do it again. This is coming from a guy who will only carry an OTF unless he is legally forced to leave it at home. I adore them. I feel naked without my CT. There isn't a knife that I feel strikes that balance between aesthetic and performance and style. However, if I manage to wear one out, it's just yet another excuse to buy something new

I don't disagree with most of this. I'd still like to prove or disprove the general consensus that they don't wear out and get sloppy from actual use, they just wear out and fail to function correctly due to the wear of firing and retracting.

Either way, I want to know how they hold up in real world use, and I am happy to keep it to myself. No big deal

 

[K.O.D.]

My primary purpose for having OTF's is it is very convenient around my sisters kids, whom I spend a lot of time with. If my da OTF falls out of my pocket and hits the ground, it's not going to bounce and open, possibly injuring one of them. I know neither my 2 year old niece nor my 4 year old nephew could open one. The 8 and 9 year olds are know not to mess with it.

Friday was my nephews 8th birthday. Having my BT small Twist Tighe was perfect for opening presents. I can quickly retract the blade after a cut and not be too concerned about one of the little ones getting hurt from randomly barreling into me.

The infrequent zip tie is usually the hardest use they get. The Manticore has done a lot of cardboard, and other than the recent issues, is ok.

 

[FrannaM]

I have done it. I am a bit obsessed with blade play and do understand OTF's do have play as a result of the design. I measured my UTX 85 when new. Horizontal play was 0.4mm and vertical: 0.75mm. Its my EDC and also my fidget tool. When I EDC the knife (4 out of 7 days ave.) I probably open and close the knife 100 times a day. So roughly in total probably opened and closed about 4200 times. Have measured play about 3 - 4 times over this period and honestly I can't see more sloppiness developed over time. I have also disassembled the knife twice (polished internals). I use the knife for normal cutting tasks only. I also could not see any wear spots on the black coating of the internal blade track. Hope this helps.

 

[SherrillMT80]

I have done it. I am a bit obsessed with blade play and do understand OTF's do have play as a result of the design. I measured my UTX 85 when new. Horizontal play was 0.4mm and vertical: 0.75mm. Its my EDC and also my fidget tool. When I EDC the knife (4 out of 7 days ave.) I probably open and close the knife 100 times a day. So roughly in total probably opened and closed about 4200 times. Have measured play about 3 - 4 times over this period and honestly I can't see more sloppiness developed over time. I have also disassembled the knife twice (polished internals). I use the knife for normal cutting tasks only. I also could not see any wear spots on the black coating of the internal blade track. Hope this helps.

Plz explain polishing to me I’ve looked everywhere for info. I’ve polished pew feed ramps triggers etc, but what n where to polish in a Microtech? Also can polishing make a difference in button stiffness?