Battle of the Navy Seals : Part I

[Cliff Stamp]

Jeff Clark :

I find that I can easily translate his numbers back into the practical and subjective arena.

Excellent, that is one of the main problems. It is all well and good to come up with a range of testing methods that give robust results, but if you are the only one who can make sense out of them then there is a bit of a problem.

Greenjacket :

... these results are not exactly earth shattering.

Pretty much, there were no major surprises. It fell into line with what I had expected based on the respected geometries with a few minor interesting parts. The only thing that I felt was odd was the extent of the tip bending on the SOG, I was not surprised that it bent, but that it could bent as much as it did without breaking. I would guess that maybe the tip was a little soft.

It should be noted that the edge grind on the right hand side of the SOG skewed towards the tip and effectively left the tip chisel ground which is probably why it bent so badly. I intend to center the tip up a little and repeat the 2x4 digging. However since it had taken a set previously through the tip, it won't react as course as will a NIB blade.

Update :

I did a minor flame test on both handles. It consisted of simply letting a wooden match burn out underneath them, with the flame just touching the grip material. The SOG grip smoked immediately, but didn't melt nor burn. Lots of blackening though, and a very aggressive dimpling pattern resulted, which interestingly enough feels very good in hand. I then repeated this on the checkering part and this suffered more damage which you would expect given the higher surface to volume ratio, still didn't catch fire.

When exposed to the lit match, the MPK's grip didn't smoke as much, nor did it melt nor catch fire. The handle also took a more aggressive texture and blackened. Grabbing the handle right after the flame burnt out was possible indicating a very low thermal conductivity, which you would expect (SOG grip was the same). It would actually be nice to use in this manner in cold weather. However I would not really recommend it because you are removing grip material, and repeated heatings will effect the structure of the grip obviously.

I also did a quick check to see if the rust resistance of the SOG was up to handling extended exposed to salt water. I used a mixture of 1tsp of table salt to 1 cup of water. I wrapped the blade in tissue paper and wet it down with 1/4 cup of the salt water mixture, simulating a wet sheath. The blade was left stand tip down, for 24 hours, in a 2l pop bottle which contained the run off from the tissure paper.

The blade had been sharpened before the soaking and tested at 2.4 +/- .3 cm on the 1/4" poly, consistent with the previous sharpenings. After the soaking the edge had degraded to 3.5 +/- 0.7 cm. Blunter but not by a huge amount considering the spread of the results, 31 +/- 17 % degredation. However after cutting some 3/8" hemp the edge quickly degraded at a very fast pace. Two cuts were made and then I could not make a complete cut even with 65+ lbs of force, four trials were attempted.

After the hemp cutting I measured the edge aggression on the poly and found a huge change, it was about 5 cm near the base right in front of the serrations, but soon took off to needing 8 cm , which was basically the rest of the blade. Basically the corrosion set inversely proportional to the distance from the tip which makes sense since that part was resting in the salt water solution directly.

The dependance of the edge degredation on edge position was consistent with the visible rust evident on the blade. Near the tip the entire edge was covered in a light brown sort of fog. As you moved back along the blade the rust was contained to just spotting. The majority of the spots were from .5 to 1 mm across, there were ~100 of them on the right side of the blade, only about 25 on the left. The blade had also corroded along the flats on the areas where the coating had been removed from previous cutting.

I have also performed similar soaks on ATS-34, VG-10, D2 etc., they will all take much more damage than the SOG 440A blade. Much more surface area will be covered and deep pitting will also be induced. The edge damage is excessive and a decent amount of material has to be removed before the edge will reform clean. Of course rusting is a very random process, I intend to repeat this a few times, changing the nature of the soaking to see how the blade reacts.

-Cliff

 

[exechobo]

Cliff, I seem to recall you reporting on cuts induced on yourself once. I want a knife that can cut someone with skin as tough as yours must be.

Cliff has been a helpful gentleman to me, with advice that I processed into my own experience and profitted from. So has Newt Livesay, a man of very different style. And Tom Mayo, a man of REALLY different style. And Duane Dwyer, the epitome of a man with style. Thanks all.

Cliff's reviews, and MANY other sources, have added to my understanding of knives. The personal attacks (and this thread is not about knives) are not of value. Now if Jerry Hossom and Cliff square off, it is fun to read and on a different level.

 

[chad234]

I am not a scientist, especially not a rocket one.
I like knives. My dog's name is Nika. Her breath smells like dog food. I am having fried rice for dinner, I like fried rice, but I also like other foods. I eat when I'm hungry. Sometimes I eat when I'm not hungry though. That may be one of the reasons I have a bigger belly than when I was younger, or it could be that I don't excercise enough.
Stay Sharp,
Chad

P.S. There are three types of people that will read this reply, those that will understand it, those that that won't, and those that think they do but really don't.

P.P.S. I forgot those that think they don't understand it but really do.

 

[C4]

Maybe we should leave the testing up to real Rocket Scientists...

Michael

PS: this card is real proof...

 

[tom mayo]

 

[chad234]

Well, now that my medicatioin level is stabalized I can more clearly write my reply.
After reading several reviews of any particular person and comparing the results they achieve with what my own observations are, and looking at what they use a knife for vs. what I use a knife for, I get a sense for the relavance of that persons reviews to my own needs.
As this relates to Cliff, I have found that much of his work with edge angles, cuting geometery and finish levels is very relavant. It basily mirrors the results that I have observed from my own use. A thinner edge usually cuts better but is less durable, a highly polished edge will be a better push cutter than a courser finished edge, but will not be as good of a slicer. Cliffs comparisons of different steels at different angles and finishes saves me a lot of time.
As to the durability of knives, Cliff's reviews do not match my own results using the same knives, hence I read them for amusement but don't really pay them much heed. What differences have I observed,
well Cliff claims that his Spyderco Military would experience liner lock faileure by squeezing it tightly. I have carried a Military for a couple of years and have used it hard. It has never failed.
Cliff claims to have damaged a Livesay RCM chopping wood. I have used Livesay Knives hard, real hard and all have performed great.
Cliff claims to have damaged the infamous MD Tusks. Every Mad Dog product I have used and seen was a high quality, durable, well designed knife.
Cliff chops concrete blocks with the edge of his knives. I do not.
Cliff claims to have destroyed knives with hard use. I use knives hard, and have never destroyed a quality product.
What does this boil down to? Cliff and I have different uses for a knife, he may be stronger than me, he may just like to destroy things. He may lie about a products performance.
In the end the reviews he writes are his opinions, just like we all have. Despite being dressed up with fancy numbers and charts they are his opinions based on how he uses and abuses a knife. They are not empirical truths, they are not carved in stone. They are his opinions.
Mine don't always agree with Cliff's, but I'm glad that we ahve a place were we can express different opinions.
Chad

 

[C4]

I meant no offence to Cliff or Tom in my last post. (Or to Tom's brother Darryl... and his other brother Darryl... seen testing the rocket with him....)

Michael

 

[Cliff Stamp]

Chad :

[durability]

Cliff's reviews do not match my own results using the same knives

This is the largest hole in the reviews currently. For example when I first got the Wildlife Hatchet from Gransfors Bruks I found that it chipped out readily chopping on knotty woods, similar damage and worse was induced when it was loaned to friends. However I spent considerable time on my chopping technique and about a year later I found the edge on the Bruks hatchet to be perfectly fine, even on the worst of woods. Loaning it out to friends however and it again chiped out. The factors of importance are the force of the swing and the control, the latter is more critical than the former. The question of interest for the reader is - if you use the hatchet on similar wood will you see damage or not? It depends on how your technique compares to mine and thus you can't make in independent conclusion. However you can look at the performance of other blades that we have both used and make a relative judgment.

As another example, I could white knuckle my Military and release the lock when it was NIB. This was a confirmed problem as noted by Spyderco as they had to adjust the lock when I returned it. However after they fixed it, and tested it to make sure it was secure, I could still cause the lock to release with a tight grip (with more difficultly than when it was NIB). Can a reader infer from this if they can cause a release? Obviously not. To make a decent estimate you would need to compare similar testing of other knives that both of us have used. In this specific case this isn't possible because I don't use a lot of folders. The only real value to making that fact public is in a statistical sense. I think there has only been only one other reported case of the Military lock releasing under grip pressure. For reference I can also white knuckle the Gunting open, though it requires an odd grip and close to the maximum force I could generate at the time.

Also, you can learn not just from the work done but by how it is responded to by the makers and manufacturers.

Despite being dressed up with fancy numbers and charts they are his opinions ...

MY SOG Seal weighed 345 g, more specifically a 95% CI would be 340 - 350 g, if you want the details on the uncertainty of the scale I was using (the calibration of which was checked against standard weights). This is not an opinion, it is measured quantity with a defined meaning. The numbers in the reviews, such as given in the above, are the same. Most are more uncertain than a simple weight, however this is reflected in the ranges given. In the reviews I do give opinions on the numbers, and the opinions are often not rigorous as I don't always define them. For example, I commented that the relative chopping performance of the SOG (not mass normalized) was not significantly different from the MPK. This is an opinion. However, if I had clearly stated what I was basing this on (a 10% difference at 5% significance) it is no longer an opinion. In general, as stated in the above, I don't go into the statistical details of the numbers, but it can be done as they are well defined, and if you want clarification all you have to do is ask.

To be really critical, the definitions for a lot of the work include such factors as my skill and strength level, which will obviously change over time and thus they can't independently be considered to be robust, as noted in the above for the hardwood dowel cutting. Thus it would be poor method for me to have a running table of work on a specific task (chop through a 2x4 for example), because as my chopping improved so would the performance of the blades used as time passed and thus the table would be skewed. This is why I have started to compare against a standard blade when such factors are involved and since the factors will scale equally with blades (to first order), I feel confident in the ratios being well defined. However if you use a radically different technique then your results can be different, this is also discussed in the reviews when such factors are significant. In the future this will be explored in detail as I will present the results of not only my work but others and thus give a more complete picture.

The last of the results for the last of Part I of the testing :

Primary edge - Push cutting

As a last test of the push cutting ability I whittled points on 1" hardwood dowel, 1" slices were used, the force used was about 45 lbs at the point of contact. The MPK took 34-38 slices to make a point. It bit in well for a knife of its size due to the full flat primary grind and decently acute and thin edge geometry. The SOG however took 72-83 slices, putting it at 47 +/- 5% of the performance of the MPK. The SOG suffered due to the thicker geometry, same as it did on the rope cutting which you would expect. Both blades had a leverage disadvantage because you had to cut so far out on the blade, a choked up grip was not used as both had squarish upper guards which generate high pressure points if you overlap them. If the plain edges extended right back, and the cutting was performed right in front of the handle, the MPK would be about ~24 lbs and the SOG ~46lbs . Both edges were shaving sharp before the dowel cutting however would not even scrape shave after. Blunting was just due to rolling, a couple of passes on a steel and they would shave again.

Serration durability

A quick inspection of the SOG serration pattern reveals its main reason for the low cutting ability. Unlike the "teeth" on the MPK, the SOG's are not fully ground by the pattern. The scallops intersect, they don't actually overlap like they do on the MPK. Thus the teeth on the SOG have very obtuse points ground at ~35-37 degrees. However this should make them very durable, in regards to both impacts and high pressure abrasion.

First I tried wood splitting. I split 12, very knotty, pieces of 1-3", 1-2 year seasoned, Pine, Spruce and Fir into quarters. A 2" thick piece of Spruce, 16" long was used as a mallet and the blade were hit with full force, which was enough to destroy the mallet at the end of the splitting. The SOG serrations were not visibly effected, a slight burr was evident, that was all. Repeating the same work with the MPK-Ti induced visible deformations. Specifically there were 7 places of visible damage. The dents were from 1/4 to 1/3 a mm deep, except for one which was 1/2" deep. The deformations were 1-2 mm in length. A few passes on a grooved steel to reform the serrations and the MPK-Ti is back to 26-28 lbs on then 3/8" hemp on the cutting block. Even before the alignment, it was still outslicing the SOG. Thus even though the SOG resisted the damage better, since the cutting ability is so low, the MPK still out cuts it.

Moving on to an extremely abusive task I attempted to cut up steel threaded tubing. This tubing is a couple of inches across and very difficult to cut on its own. The wire that is along its length however makes it near impossible to cut and hell on blades. Even with very high forces applied (>75 lbs), both knives could only score the tubing after a dozen passes, neither could cut through more than a few pieces of wire, the SOG doing better than the MPK at that. However while the SOG tips were just blunted, the MPK-TI serration pattern was completely worn flat. Trying out the blades on some 5/16" poly, the SOG now clearly had the advantage, taking only ~3 passes to cut through the poly, while the MPK, with little aggression remaining, required from 10-12. Fixing both patterns required a simple filing on the back to reform the teeth as well as some work with a 600 grit DMT rod in the scallops. Both blades would now cut the 5/16" poly in less than one slice. The MPK was more aggressive on the 3/8" hemp on the cutting board, it would cut through it requiring 41-43 lbs, the SOG needed 62-68 lbs.

Part II

Should be started in a week or so. The knives will be modified, blade as well as grip, the SOG moreso than the MPK which will just see minor edge reprofiling. The influence of these changes will be explored relative to the cutting ability, edge retention and durability, point strength, and handle ergonomics plus misc. .

-Cliff

 

[HUNTER3897]

Dan/bandaidman,

Thanks for saving all of us. You've been here for under a year and have already figured out what Evil Cliff is up to. Thanks for setting all of us old timers straight. Do you really think that you have said anything new? Let me clue you in on some BFC history. Cliff has been around the game for quite a while now. Long before BFC was even around. In the beginning, he was just a guy who had what seemed like an obsession for testing knives to their limits. All in the hope of finding the ultimate steel, handle, edge geometry, etc... He started to attract attention from a lot of people who really loved his reviews. What did Cliff do? He just kept on testing. Then people started saying that Cliff should become a writer, or at least a Moderator. Finally, someone wised up and made Cliff a Moderator of their Review and Test forum. (BFC-Mike and Kevin) Cliff started to become very popular, raised up to an almost God-like status. Everyone wanted to be Cliff's friend and have him do a test on the knife they just bought. What did Cliff do? He just kept on testing. Cliff was at this level for quite some time. Then some of the big players in the knife world didn't like what Cliff had to say, so they started the process of tearing him down. It took a while, but pretty soon it wasn't cool to be one of Cliff's fans. All of his "friends" just seemed to disappear. What did Cliff do? He just kept on testing. Then his Moderator title was removed. People really started taking their cheap shots at him then. My favorite was that Cliff only tested knives so he could get freebies. If you didn't give him a knife to test, he would really get you in his next review. You know what though Dan? Every time I asked the accuser to give an example of this, you know, just give a little credibility to their personal attack, they never had it. It always ended up being something they had "just heard" in another thread or in an email. The same old crap being slung around to try and discredit Cliff. What did Cliff do? What has Cliff always done when they start slinging mud? He doesn't get caught up in their personal attack crap. He just keeps testing knives. The best way he knows how.
What's the point to this??? Cliff has been attacked by people a lot more thoroughly then you have been able to muster. He was here before you got here, he'll be here after you are gone. If you don't like how he reviews things, how about if you show us how it should be done. Until then, why don't you stay the hell out of his threads. What you have to say isn't anything close to being original, and people are really growing tired of the "bash Cliff" game.

Jim McCullough

 

[bandaidman]

Wow, remarkable posts

Jim, you can believe whatever and whomever you want. (edit: by the way the length of time I have posted here has little relevance, I have lurked here since early 1999, does that make a difference?)

There are people who sincerely believe that the world is flat and that there is an Easter Bunny. They even have references.....

The plain fact is that Cliff loves knives but seems to have a limited understanding of statistics and their proper application. As Winston Churchill pointed out there are "lies, d*** lies, and statistics." Not everything Cliff says is poppycock but he exaggerates the statistical significance of his results for reasons that remain obscure to me.

I do not doubt that the Mission knife is superior in many respects to a 440A Sog blade as Cliff reports. My beef is that he tries to impress everyone with statistics when they have little scientific value.

Test of medians????? It would be quite unusual for the scientific or medical journals I read to accept that comparison as a sufficient proof that one test subject is superior to the other.

340-350g weight of the same knife with a 95% CI as related to the accuracy of his scale?????

So what!!! That does not validate his end conclusions, it means he has a mediocre scale.

calculate the p value of your study Cliff and see if it makes the grade......

I think it is great that Cliff wants to test knives, he should just avoid trying to impress people by analyzing the results in ways that is not supportable by his data.....that is my suggestion.

 

[Cliff Stamp]

Bandaidman :

[median based statistics]

It would be quite unusual for the scientific or medical journals I read to accept that comparison as a sufficient proof that one test subject is superior to the other.

The median as a measure of central tendency is much more robust than the mean or average. The average is more popular because it is easier to deal mathematically. This method of analysis is what is taught as an introduction and thus it is what the vast majority of people use for data reduction. If you are dealing with true Gaussian based events then the median holds no advantage, but real physical measurements are not Gaussian in the tails. Specifically events with very low probabilities happen at a much greater frequency rate. These outliers can cause the mean to be significantly altered, they have no effect on the median, thus it is more robust.

In regarding testing two samples, you don't test that one is "better" or "superior", you perform either a one sided or two sided test depending on if you want to tell if the statistics are significantly different, or if one is higher or lower than the other, the latter being a more specific test than the former. Specific to median based statistics, the median can be scaled by IQR / (1.075 * sqrt(n)) to get a statistic that has an approximate t distribution with n-1 degrees of freedom. This is from "Understanding Robust and Exploratory Data Analysis" by Hoaglin, Mosteller, and Tukey. You can then perform the standard tests on the derived statistic to whichever standard of rigor you feel is necessary.

The latter bringing up an obvious point which is grossly overlooked in the above. Statistical testing is only actually required when the differences in quantities is comparable to their spread. For example if I weigh two knives and one is 500 g and the other is 700g, no statistical testing is required on the numbers to state with confidence which knife is heavier than the other. However if the weights are 500 and 510 g, then you have a bit of a problem. You have to consider how much the masses of each can change from knife to knife as well as the precision and accuracy of your scale.

340-350g weight of the same knife with a 95% CI as related to the accuracy of his scale????? So what!!! That does not validate his end conclusions, it means he has a mediocre scale.

That was not meant to validate the conclusions. First off that was meant to clarify that all physical measurements have uncertainty, and secondly to point out that if rigorous statistical language was used throughout the post it would become quite unreadable for most with no extra value. In regards to the scale, the divisions are 20 g, which means that I can read it to 2 g with care. I don't estimate beyond 5 g however because often the size of the random uncertainties are greater than that. When this is not the case, such as when I am weighing a knife, I don't see the value in going beyond 5 g as a tolerance anyway. You have to look at what level of tolerance you want to measure and use equipment that can measure to that level. Specific to my knife work, I don't have a problem with a tolerance as high as 5% as it allows me to discriminate at the level I desire.

calculate the p value

As an example of statistics that offer nothing beyond the obvious :

SOG SEAL = 77 +/- 6 lbs
MPK-TI = 51 +/- 3

We wish to test the significance of the performance advantage of the MPK-Ti. That is to say is the difference real, or just a random correlation. A 95% confidence interval of the performance difference is 12.6 <-> 39.4 lbs . Therefore it can be stated with a 95% confidence that the MPK-Ti will cut the rope with less force than the SOG SEAL. It also passes a test of 99% significance. You can of course use even more language if you want, the null hypothesis is not supported with 95% confidence, and thus you can conclude that there is a significant difference in the central tendencies of the two samples in favor of the MPK. You can also look at the numbers from the point of view of p-values. These are just the probability that that you are seeing is simply random. For the above, the p-value is far less than 5% (t value > 3), and thus the conclusion would pass (MPK > SOG) at that level of signficance, as well as at 1%.

Again, I don't so testing of this type, not because it can't be done, but simply because I feel that if you have to be this rigorous to reach a conclusion, you are looking at a difference that is not significant in regards to field use anyway. It is simply far beyond what needs to be done. For example anyone who cut with those knives would have easily been able to rank them, as a ~25 lbs difference is easily felt. Thus I concluded that the MPK outperformed the SOG. As shown in the previous paragraph this conclusion can be supported with statistical tests, if you wish.

The standard errors in the above could of course have been reduced with repeated testing. I didn't feel this was necessary because quite simply the performance difference is far too large and it is obvious that the MPK out cuts the SOG SEAL after just one cut. I did more cuts (12 for both), as I am interested in how geometry effects cutting performance and thus I need more specific information than just does the MPK outperform the SOG. Specific to that, I'll be refining the results later on with the reprofiled blades.

-Cliff

 

[HUNTER3897]

Originally posted by bandaidman
Wow, remarkable posts

Jim, you can believe whatever and whomever you want.There are people who sincerely believe that the world is flat and that there is an Easter Bunny. They even have references.....
I think it is great that Cliff wants to test knives, he should just avoid trying to impress people...

For someone who doesn't read Cliff's reviews, you sure check in a lot. Didn't take you long to respond. As your above quote shows, you sure are a condescending fellow. Again you ASSume that nobody but you knows anything about the proper way to do unbiased tests. Cliff is the first one to point out weaknesses in his testing method. But of course, you always skip over Cliff's reviews so there is no way you would know that, right? Do you really think that no one else can see flaws in his method? How do you reproduce the exact same angle and pressure from cut to cut? You can't. So what??? We can still gleen important information from the findings. (Well at least us underlings can.) If you want to see someone else engage Cliff infinitely better than you, do a search of Hoodoo's posts. You also are able to jump into Cliff's head and know that his sole reason for doing the tests is to impress people. Since you are so smart, you should have been able to figure out that if someone blew up the convention center that the Blade Show was in, Cliff still couldn't get a job in the knife industry. If he is "trying to impress people", he sure has been going about it the wrong way since day one. Maybe you can also enlighten Cliff on how to "impress" people since you have done such a good job here. You see Dan, we have to go through this about every 3-6 months. Someone wants to make a name for himself here at BFC. So how does he do it? He doesn't go out and do his own reviews. He doesn't go out and show us the "right" way to do it. He just lazily sits at his computer and tears down how Cliff does reviews. You're just another in a long line of people trying to make a name for themselves by attacking Cliff. As I said earlier, it has grown very old. We can see flaws in what Cliff does. We don't need people like you, who are the real ones trying to "impress" people, to save us. Please just go away.

Jim McCullough

 

[Cliff Stamp]

Jim :

We can see flaws in what Cliff does.

Infidel !!

Jim I appreciate your comments, however posts like Bandaidmans actually serve a number of valuable services. First and foremost, without people responding in such a manner I would not appreciate those who are positive. I have gained a tremendous amount from interactions from people through the reviews, posts like Bandaidmans are necessary to put those interactions in the perspective they deserve.

Secondly, it also causes people to think about what I am saying, and that is never a bad thing. It would be very bad if you just accepted something I said and let it over rule what you thought was true simply because I said it. Rants like the above, and yours and others comments, plus my own, give a more complete picture of the review. Yes I realize that there are those that will be swayed completely away, but that is a loss I am willing to take.

Finally it keeps me critical, it keeps them changing and hopefully improving.

There are better ways of course to be critical, for example note Crayola's comment about sharpening. However while I would prefer such interaction, I would rather have a negative post like Bandaidmans than none at all. The intent of course is completely different, but that can simply be ignored.

-Cliff

 

[bensano]

Cliff

It has been 30+ years since physics lab 101. Thanks for the review and the memories.

Ben

P.S And Leftys ARE still being made, at least until Microsoft gets control of the human genome.

B

 

[exechobo]

Bandaidman, is there a review that you can point to that is satisfactory to you? Because you really won me over with the observation about people who believe in the Easter Bunny. That was so on target, so insightful, it caused me to realize that Cliff's body of work (hobby) is suspect. Then I suddenly began to think critically and realized that the 5 gram variability in the measurement of knife weight undermined my whole understanding of what happens when I slide a knife blade along the belly of a whitetail deer! Sheeesh! Why does he post such da**ed statistics? ( I really like that quote, it can be used instead of thought anytime, several times each day.)

Jim, boy can we ever see flaws in what Cliff does. I still avoid his test of that Strider. I just can't bear it!!!

Cliff, please don't give us so much of that numbers stuff anymore. My head is gonna pop! It has been my experience that Canadian numbers are different than American numbers. They are usually generated a lot closer to magnetic north. I have been suckered for last time by your clever use of stastistics... now what do I do with all my knives? Oh, and good ripost! When you do humor I usually fall off my chair!!!

ps Cliff, the convex sharpening is coming along well, and I am trying to master the use of a stone to make the system more portable. THANK YOU for your help.

Paul

 

[Cliff Stamp]

Ben :

Leftys ARE still being made, at least until Microsoft gets control of the human genome.

They would still get made then by request. You would opt for a left, and get no hands. The upgrade would come out which you would have to buy and it would give you a hand but no fingers. Another upgrade would give you the fingers but no thumb. By the time you finally get a fully working hand you have had to also upgrade your arm. It is about this time that you realize that you would have made more progress if you learned how to just make due with your feet.

Paul :

... it caused me to realize that Cliff's body of work (hobby) is suspect.

The part about this that strikes me as most amusing, is that most often a criticism is made with a loud exclamation, as if it was revealing an event of the scale as the Emperor is wearing no clothes, when not only is it already common knowledge to me, it is public knowledge as it has already been openly discussed years past and is commented on in detail in the reviews. The most informative points are usually made in a manner similar to Crayola commented about sharpening, which you would expect given what it reflects concerning intent.

Statistics do have their place though, I don't want to give the impression in the above that they are not useful in general for knife work. I have collected edge retention data on a dozen or so blades now cutting 3/8" hemp rope. I have been doing non-linear regression on the data with a simple log model of blunting. The model is based on simple physical principles and agrees strongly with the data, which you really need to verify with appropriate tests of significance.

I have learned quite a few interesting things about edge retention from looking at the numbers in detail. As with everything, it seems quite obvious once you know it. There are a few odd points that I need to work out, plus I need to rerun some of the knives for verification plus look at some others for a wider sample, but it looks like it will be much more informative than I expected.

Why does he post such da**ed statistics?

It is a really complicated plot and it goes like this; about 20 years ago Jerry Busse started making knives, after considerable success he realized it would be both fun and very promotional to "create" an adversary. This is when Busse started Cold Steel and shortly after came the Trailmaster vs Battle Mistress. After awhile Busse realized that it would be again fun and promotional to have an "independent" person do some comparisons. This is where I come in. Just like Lynn, I am also Jerry Busse, and just like Lynn I have a very different personality as otherwise it would be far too obvious that we were all Jerry Busse. Having an odd sense of humor Busse created a lumberjack/hillbilly/scientist persona, to represent an individual who chops down a few hundred trees and then gives out pages of statistics on the number of chops per tree and how this was influenced by the wind vectors etc. . Busse then realized that the "persona" would become more complete if it interacted with others so he created other "characters" like Will York to feed the main persona questions to enable it to have a platform, with it being too obvious.

It has been my experience that Canadian numbers are different than American numbers.

Its the weather. We got 40 cm of snow yesterday and while I was out shoveling out the driveway (200 ft or so), at -5, with freezing rain, it comes into my head, "Well there is a fair amount of snow, but at least its not cold.". How is that for a skewed perspective. My dog seemed to think so as well and he definitely believes in the Easter Bunny or something similar as he was constantly sprinting at full speed at nothing, then coming to a dead stop looking quite confused.

the convex sharpening is coming along well, and I am trying to master the use of a stone to make the system more portable.

Glad to hear it. You want to hear something really odd. I switched to freehand convex on benchstones from sandpaper about a year or so ago, I find that now freehand on v-grind edges is much harder. That is like being able to swim but yet drowning when you fatigue as you can't tread water.

Back to the knives, all three have been re-profiled down to ~9 degree edges. I also reworked the tip on the SOG and on the MPK-A2. It will take 1-2 weeks for the low stress edge retention and general cutting, and at least that long for the chopping and splitting and point work. Some test cuts on the SOG show it now cuts very well, the MPK-A2 is quite a monster of a cutting machine with a full flat grind and a ~9 degree edge. The MPK-Ti was a beast to re-profile compared to the A2, I realize now why John was not that hot to come out with a 10" bladed MPK-Ti.

-Cliff

 

[exechobo]

ohmagaad! This is too good. I KNEW there was a conspiracy by Busse. No wonder you (he) destroyed that Strider. At least I can safely ignore the results of your so-called test and stay comfortable in my belief (supported by personal observatons, and isn't that the only thing that matters?) that Strider rules! Jerry is so clever to make you a Canadian too. Quelle Diabolique!!

By the way, I fully agree that hundreds of tests regressed can make up for lack of perfection in control- in some ways this is more meaningful. As for what we do here, its good enuf. This is stll about fun, right?

Paul

 

[Will Kwan]

Cliff,

Did you notice any change in durability with the reformed serrations after splitting?

The handle not retaining much heat shows it has a low heat capacity.

I agree that skill makes a big difference in the amount of force a blade will experience. Last year I chopped the legs off a deer with my H.I. village khukuri. The edge was unaffected and it took approximately 3 chops to remove the legs except for the last one. I came kept coming in at random angle on the last leg. As a result it required around 13 blows to remove and the edge was dented in the softer zones and less so in the harder zones (barely visible).

Will

 

[tom mayo]

 

[HUNTER3897]

Cliff,

You better watch out if you're going to be doing comedy on a regular basis, or you might lose that cold, killer robot image you have created for yourself.

Jim McCullough