All New MountainManDu Coming Wednesday 12-13-17. . . Specs, Pics, & Pricing!!!

MR HAPPY said:
Yep I remember that one.
He got it back from a modder after having the blade thinned out and the edge took damage chopping wood whilst doing a short review on camera. Please remember this is a professionally MODDED blade by Josh @ REK and not as it came originally from the Swamp...Here's the link below;
If you don't want to watch the whole thing just skip to around the 7min 50 sec mark and you will see the edge damage that I believe Sigarett is referring to.
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...... I believe that Richard (W-Wood and REK went back and re-did that grind after the test as well with those results in mind. Or that was my recollection.
 
Anyone know what the dps was for the knife in the video. That is good data but almost worthless without knowing the dps.
 
Closer to the full story on 'Wood's reground MMD from him and Josh at REK...

worldwood said:
Thanks bud, i wasnt real surprised at the damage either. Its S7... If it was 52100 i would of been disappointed. I know what 52100 can do, even super thin. But this is my first time experimenting with S7, and i had R.E.K. take it a bit too thin. He gave me exactly what i asked for so i only have great things to say about his services. He even offered to fix the "damage" for free.... But i declined, no reason he should work for free after doing great work the first time, so i told him i would pay for the re-sharpening, and i will be sending it back to him in the near future for that.... Great guy, and he does great work too!!

I dont recall what it was at originally. Now its at 4° primary and 15° secondary with around .03" behind the edge.

Next we will be trying 17° secondary.

I know a lot of people think this is too thin for choppers, but im not one of them LOL.... Now obviously im figuring out its too thin for this steel, but i have a couple 52100 blades that perform amazingly even thinner.

The goal is the thinnest edge possible that can still hold up to the abuse, and without testing different geometry on a new steel i cant figure this out. So more testing will be done!!

S7 has a lot of great characteristics for a large chopper, but holding a perfect edge when thinned down to .03".... Well thats not one of them LMAO

Its an excellent blade though, love the ergos and general profile of it. Ill get it fine tuned in time, and will of course share what i find!!
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razor-edge-knives said:
I know we've been emailing back and forth Richard, but I figured I would post up pics here for anyone interested =) plus I would love to hear others experiences on edge stability.

So when I got it back in I removed damage by grinding stone directly into edge until mostly at the bottom of the chips/dents so as to remove any damaged and fatigued metal. Then I sharpened it on my belt sander (water cooled) to 17 dps, .040" thick at the shoulders of the edge. Then after getting permission from richard, I took it out to some dry hickory. I found the knottiest (word? lol) piece of hickory I could find and commenced to chopping away...

IMG_20150523_131731.jpg


Didn't get very far before I found this:

IMG_20150523_132009.jpg

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So I took it back in, but this time I took it to my Wicked Edge and put a final bevel/increased the secondary to ~22 dps... all cleaned up:

IMG_20150523_133323.jpg

IMG_20150523_133329.jpg


Then I took it back out and went to work again, finished chopping original log in half and then batonned it up, then started in on a huge piece (that I didn't finish up cuz I was getting worn out lol). Every time I hit into the large log towards the center, I could hear a "chink" like it was hitting metal or concrete, that's how hard this stuff is :) But I wasn't taking it easy... I was being a little sloppy and twisting the blade as I took it out somewhat (mainly when starting a cut). Also, When batonning I wasn't babying it, I was nailing the tip even though it was only poking out 1-2":

IMG_20150523_141347.jpg

IMG_20150523_134512.jpg

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After the above work I checked the edge again. Below is the worst damage I could find and it would still cut cardboard great and printer paper. although there were a couple spots where it snagged, it still made it through pretty good. Would not shave arm hair at all though.

IMG_20150523_142543.jpg

IMG_20150523_142556.jpg


After talking with Richard about the above, I am going to clean it up a tad, work the relief bevel (at 17 dps) a little bit, then finish it up on the Wicked Edge before going out. Please post up your experiences guys as I am curious. And Richard, when you get it back please let me know how it performs and holds up.
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Thanks. That is excellent information. I was going to go 20 dps with it. So that should work.
 
.04" behing the edge is a very skinny blade. I am not surprised it rippled. S7 is very ductile.
 
Cobalt said:
.04" behing the edge is a very skinny blade. I am not surprised it rippled. S7 is very ductile.
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Actually 0.04" is pretty thick edge even for a chopper... Most cutting competition blade are need to be thinner than 0.02" to perform great. Keffeler personal blade is even 0.008" behind edge thickness.

Steel with low carbon such as 5160, L6 etc will suffer from some kind of edge deformation due to the lack of strength even at the same HRC compare to the higher one like 52100, W2 etc from my experience.

This is the reason why CPM-M4 is a better choice for comp. blade over CPM-3V.
 
shqxk said:
Actually 0.04" is pretty thick edge even for a chopper... Most cutting competition blade are need to be thinner than 0.02" to perform great. Keffeler personal blade is even 0.008" behind edge thickness.
.
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You know what I was thinking of how I measure which is 0.2" behind the edge. Duh. I measure all my blades there. So I guess that .04 makes sense, lol
 
shqxk said:
Steel with low carbon such as 5160, L6 etc will suffer from some kind of edge deformation due to the lack of strength even at the same HRC compare to the higher one like 52100, W2 etc from my experience.

This is the reason why CPM-M4 is a better choice for comp. blade over CPM-3V.
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M4 may be a better comp blade, but it is not a better blade steel for long term chopper usage. It will chip and break well before 3V will and certainly well before L6, S7 and many other tough steels. Comp blades need just enough toughness to get through a contest with an edge that holds up.

M4 has less toughness than all the steels I mentioned. I would take 3V and 4V over M4 any day of the week. I would also rather have S7 for a hard use blade. It is so much tougher that they are not even in the same class of toughness.
weartoughgraphweb.gif



How long do you think that an M4 blade would have lasted be hit like this for 6-7 minutes straight with a hammer.

This 1095 crovan blade lasted just over a minute ish.

MuVR3J9.jpg
 
Cobalt said:
M4 may be a better comp blade, but it is not a better blade steel for long term chopper usage. It will chip and break well before 3V will and certainly well before L6, S7 and many other tough steels. Comp blades need just enough toughness to get through a contest with an edge that holds up.

M4 has less toughness than all the steels I mentioned. I would take 3V and 4V over M4 any day of the week. I would also rather have S7 for a hard use blade. It is so much tougher that they are not even in the same class of toughness.
weartoughgraphweb.gif



How long do you think that an M4 blade would have lasted be hit like this for 6-7 minutes straight with a hammer.

This 1095 crovan blade lasted just over a minute ish.

MuVR3J9.jpg
Click to expand...
Yes M4 type steel is like F1 of blade steel. The best for some specific application but properly a poor choice for others.
 
Cobalt said:
What a way to start off. Cograts.
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Thank you Sir, I can't wait. Somehow I finally found the Busse order website on an early am search for a new knive from somebody I had not had the pleasure of owning yet.
Looking at my knives now, some are gonna go to make room for a few more Busse; from what I see & read, I like...
 
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