M390 VS ZDP-189 Rope Cutting - Informal testing

nozh2002 said:
It does not look like micro chipping - on the photo I see very very tiny shine line on Endura edge - chipping would not look as a bright line. On BM it is way bigger. So M390 edge was damaged much more then ZDP-189.

Thanks, Vassili.
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You really can't tell by the photo as I said.....

The edge was really torn up believe me. ;)

Once I get the next Endura and run the last stage I will take better photos of the edges once it's done to show the damage.

I wasn't that concerned about showing the edges when I took those photos.

I have a blurry photo of the Endura's edge that might show more, but it's not clear.
 
Here is the bad photo, as I said I wasn't worried about showing the edges, but you can see some of it, it was worse than it looks here.

Endura_4_580_cuts_2_cropped.jpg
 
Ankerson said:
You really can't tell by the photo as I said.....

The edge was really torn up believe me. ;)

Once I get the next Endura and run the last stage I will take better photos of the edges once it's done to show the damage.

I wasn't that concerned about showing the edges when I took those photos.

I have a blurry photo of the Endura's edge that might show more, but it's not clear.
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Can you also show them cutting paper after test. Better show difference between ZD189 after it finished (let say 580 cuts) and M390 after same amount of cuts ZDP-189 ended up (580).

Why do not you do simple cut with saw in that wood to prevent edge hitting wood? That bended edge is much bigger in re curve I think because it is not exposed to the wood as much as one at the beginning of re curve.

Thanks, Vassili.
 
nozh2002 said:
Can you also show them cutting paper after test. Better show difference between ZD189 after it finished (let say 580 cuts) and M390 after same amount of cuts ZDP-189 ended up (580).

Why do not you do simple cut with saw in that wood to prevent edge hitting wood? That bended edge is much bigger in re curve I think because it is not exposed to the wood as much as one at the beginning of re curve.

Thanks, Vassili.
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I can't change the format that way because if I did I would have to start all over again from the beginning with all the knives and that's just not going to happen. ;)

The overall results won't change so there is no need, the margin is too great.

The format that I have is working for my purposes and it seems to be consistent enough for me, and it been very predictable down to the number of cuts that the knives made to a point. :thumbup:

I knew the New Endura would cut better than the old one, It did and by a predictable amount as Sal Glesser pointed out.

I knew about what the M390 would do cuts wise by the 1st test and the results were predictable to a point. I wasn't suprised by the end results or the amount of cuts made with each knife.

I might do a video of them cutting paper after the finial Stage is done. :)
 
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Ankerson said:
I can't change the format that way because if I did I would have to start all over again from the beginning with all the knives and that's just not going to happen. ;)

The overall results won't change so there is no need, the margin is too great.

The format that I have is working for my purposes and it seems to be consistent enough for me. :thumbup:

I might do a video of them cutting paper after the finial Stage is done. :)
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Well, the question of how re curve affects results will remain, then. Can you at least not use re-curved part - tape it with ducktape or something. Obviously edge looks different in and out of re-curve. I am not sure if removing re-curve is and option for you.

I understand that you did quite a lot already, but did not I asked for this from the beginning? Again in my testing (I did by your request only, because I did not believe BM will be able to do any good) M390 performance was far behind - pretty average on the same CPM S30V level.

Thanks, Vassili.
 
nozh2002 said:
Well, the question of how re curve affects results will remain, then. Can you at least not use re-curved part - tape it with ducktape or something. Obviously edge looks different in and out of re-curve. I am not sure if removing re-curve is and option for you.

I understand that you did quite a lot already, but did not I asked for this from the beginning? Again in my testing (I did by your request only, because I did not believe BM will be able to do any good) M390 performance was far behind - pretty average on the same CPM S30V level.

Thanks, Vassili.
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I am not really using it, I am not cutting the way you think I am. ;)

I am push cutting, rocking the blade from tip down, not cutting in a slicing motion, it's a lot more consistant that way.
 
Here are some Latrobe charts on different knife steels. 20CV is close to M390 in performance, but not exact as Jim has pointed out.

http://www.latrobesteel.com/assets/documents/datasheets/Blade_Steels.pdf


http://www.latrobesteel.com/assets/documents/datasheets/Knife_Steels.pdf

These charts go to show that however the foundry is testing the steels, they do hold 20CV to be very wear resistant.

Wongki, PGK is the powder version of the old standby, vascowear/cruware. There's also a popular mechanics from april 87 about the new knife steels that talks about it ( Plain ingot vascowear in the gerber sportsman 2), and the then new T440V. http://books.google.com/books?id=0eMDAAAAMBAJ&pg=PA92&lpg=PA92&dq=gerber+vascowear+v+steel&source=bl&ots=kB5xM1Alsc&sig=kiFknCLLDqxVvVWUmIEF9arRsWM&hl=en&ei=FaNVS7r-IM-ztgeRvvyoCQ&sa=X&oi=book_result&ct=result&resnum=7&ved=0CBcQ6AEwBg#v=onepage&q&f=false

Here's some tests by Wayne Goddard with some familiar steels: http://sharpeningmadeeasy.com/edge.htm
 
Ankerson said:
I am not really using it, I am not cutting the way you think I am. ;)

I am push cutting, rocking the blade from tip down, not cutting in a slicing motion, it's a lot more consistant that way.
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Then how did it developed quite a rolled edge there?
 
Ankerson said:
Same way the Endura got the Micro Chipping on that part of the blade. ;)
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Did not you just sad:

Ankerson said:
I am not really using it...
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So you are using it, but it was not exposed to the wood. If so with one knife BM710 you cut only rope and with other Endura - rope and wood. This is why you manage to cut more rope with BM710 M390 then with Endura ZDP-189.

On my tests after cutting rope 200 times Endura ZDP-189 stays much sharper then BM 710 M390. Endura ZDP189 need 4.5 oz to cat cotton thread after 200 1/2" manila rope (no wood) cuts (median from 21 measurement). While BM710 M390 after same load (200 cuts of 1/2" manila rope) need 7.5 oz.

So difference is huge Endura ZDP-189 is on 4th place and BM710 M390 is on 21th place. This is very different that what you have here when you sad M390 is way ahead of ZDP-189. Most likely this is because of in you case those knives has different load - one is rope only and another is rope plus wood.

Of course there are other questions - like initial sharpness. Are you sure your ZDP189 and M390 have same sharpness before test? Are they both whittle hair for example?

Is end of test criteria equal? On that pictures M390 edge is much more damaged then ZDP-189. I actually never see this being so bad, but you are saying it is somehow same or better then ZDP189.

Did you run same knife several times to make sure that every time you have same results? Last one is scariest one, but I did it and not pretty sure in my test consistency.

Thanks, Vassili.
 
nozh2002 said:
Did not you just sad:



So you are using it, but it was not exposed to the wood. If so with one knife BM710 you cut only rope and with other Endura - rope and wood. This is why you manage to cut more rope with BM710 M390 then with Endura ZDP-189.

On my tests after cutting rope 200 times Endura ZDP-189 stays much sharper then BM 710 M390. Endura ZDP189 need 4.5 oz to cat cotton thread after 200 1/2" manila rope (no wood) cuts (median from 21 measurement). While BM710 M390 after same load (200 cuts of 1/2" manila rope) need 7.5 oz.

So difference is huge Endura ZDP-189 is on 4th place and BM710 M390 is on 21th place. This is very different that what you have here when you sad M390 is way ahead of ZDP-189. Most likely this is because of in you case those knives has different load - one is rope only and another is rope plus wood.

Of course there are other questions - like initial sharpness. Are you sure your ZDP189 and M390 have same sharpness before test? Are they both whittle hair for example? I end of test criteria equal? Did you run same knife several times to make sure that every time you have same results? Last one is scariest one, but I did it and not pretty sure in my test consistency.

Thanks, Vassili.
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I am testing to the point of edge break down, that takes a lot more than 200 cuts with these Super Steels. ;)

That tells me more of what I want to know about the steels, how they act as the edges break down in different stages of sharpness.

Yes the knives were all way beyond hair whittling sharp I can tell you that.

The edges are the same angle at 15 per side on all the knives also, except the 1st Endura that had the 15 degree Micro bevel and the blade was worn more. Like I said very predictable as the NIB Endura reprofiled did better than the old one and by a predictable amount.

My testing method works for me, it's predictable and the rope is harder on the edges than the wood is.

My method will not change from how it is currently when cutting rope as I said before it works for me.

There will be more steels tested in the future using the same method, not all of the steels, but a number of them as I get the knives in the steels to test.

No test is conclusive or the last or final word, they are just what my finding are the way I test and with the materials that I am using.
 
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You could add a mini-griptilian in M390 or BM 755 MPR to your lineup in order to take the recurve out of the equation.

I don't know about you, but I would sooner eat my 710-1 than take the recurve out of a limited edition knife.
 
I would take the recurve out of a 710-1 just so I could use it :p

Are the shiny bits on the BM blade rolls Ankerson?
 
If in the name of discussion we would want to find out how much the wood base effects results, two runs of the test would be needed. One having a wooded base and another one with a cut in it to avoid blade edge touching the wood.

Comparing the results would hopefully tell if the wood base had significant effect? Im certainly not demanding anyone to do it just thinking what would be the work required...
 
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nozh2002 said:
So you are using it, but it was not exposed to the wood. If so with one knife BM710 you cut only rope and with other Endura - rope and wood. This is why you manage to cut more rope with BM710 M390 then with Endura ZDP-189.
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I see where you are headed here. Perhaps Jim could (in future runs) take photos of the belly of the re curved blade (where we might expect the wood impact to be greatest). Perhaps not conclusive, but if there is less damage visible there than in the recurve perhaps everyone can better understand how significant the input from the wood is or isn't.

This sort of serves as a test of the test. Either way the test is valid but perhaps some would appreciate what is really going on here a bit more. More learning with zero change in method and very little additional effort. Win win?
 
Hair Whittling is easy, all the knives I sharpen will do it with no problem.

My Custom Demko here., the hard part is not cutting the hair because they are so sharp once I am done. ;)

That's why I use the TP test, if it will slice TP like in my video it will whittle hair easy, just different levels of sharpness.

DSC_0777_cropped.jpg
 
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PatriotDan said:
If in the name of discussion we would want to find out how much the wood base effects results, two runs of the test would be needed. One having a wooded base and another one with a cut in it to avoid blade edge touching the wood.

Comparing the results would hopefully tell if the wood base had significant effect? Im certainly not demanding anyone to do it just thinking what would be the work required...
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Yes this is what I did already and effect is significant - you may remove rope out of this equasion because it has less effect on edge. But without rope it is clear that load would be random and out of control.

Thanks, Vassili.
 
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