So I got a DMT aligner kit and, well....

P

PC87

Joined
Dec 27, 2011
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Got this last week and ordered the Extra course stone with the kit so re-profiles would take less time. I started with an old spydie native in s30v and started to re-profile. Went through all the grits at about 15 degrees and it wouldn't shave my arm or really cut paper cleanly. So I went back and started over again with the same results.

I did put the dmt stones on the 15 degree of the SM setting after the fine stone using the browns, then the fines, but it was still dull feeling and wouldn't cut paper or any harm hair so I figured why go on the the UF's and strop.

Got frustrated and put the DMT stones on my SM rods at the 40 degree setting for a micro bevel to see if I could get it sharp that way.

After about 6 minutes going through the DMT stones, then going to the brown, fines, and UF's stones then strop, I have a hairless arm now. I mean you couldn't even hear it going through phone book paper much less feel it.

My question would be why couldn't I get that edge at the 15 degree setting on the aligner?

Thanks
 
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Because on a system like the aligner the angle markings are more of a generall guide than a precise measurement. Its been my experience that they tend to be a bit lower than you actually intend , depending on how tall your knife is. So you may have been trying to put a more accute angle on the knife than you realised.

I strongly suspect that you were working on the shoulder and not actually getting the knife to apex. Also whats the finest stone that comes with that kit? Diamonds scratch deep and leave a much coarser finish than many people realise. Even the fine DMT stuff is much coarser than a similarily graded waterstone.
 
The last stone is the 1200 grit green stone, and it felt like I was apexing and not hitting the shoulder. After the course stone it reminded me of the way the native came from the factory with a high bevel. I could push cut but it was grabbing.
 
Did you use the sharpie trick and raise a burr on both sides?
I doubt i wpuld be able to shave off the 1200 dmt...
 
I did and it worked great.

After only using ceramics and this being my first time using diamonds, they are a lot more aggressive than the ceramics and it would seem you would have to get a pretty high grit diamond stone to get the same affect of the ceramics. The micro bevel that I managed to get on there is just crazy sharp but I wanted to try and not use a micro bevel and just have a 15-17 degree edge like all you guys can get scary sharp.
 
I've had similar experience with the DMT, at about 20 degrees per side. I will go through all of the grips and the blade will be fairly sharp even though it won't feel so sharp. Sometimes I can cut thin paper easily, sometimes not. I made a strop to use with the Aligner system by gluing a piece of leather to a thin piece of wood, shaped about the same as one of the DMT stones. I put some gray compound on it that I had leftover in the garage. A few strokes with the strop and it gets really sharp, and the edge looks nearly polished.

I don't know if I am using the DMT stones correctly. I use the sharpie and apex the edge, looking for a burr, with the coarse stone. Having reached the edge I use the medium and fine stones for a few seconds each. I don't know how much I should use these stones and I might not be using them enough. I have already reached the edge so I think all I need to do is to remove the coarse scratch pattern.
 
Sadden said:
Did you use the sharpie trick and raise a burr on both sides?
I doubt i wpuld be able to shave off the 1200 dmt...
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I thought he was talking about "shaving" arm hair. You certainly can do that with the 1200. Russ
 
When you say you had it at the 15* setting of the DMT aligner, do you mean you had it at the lowest setting or did you modify it in some way?
 
Revival29 said:
When you say you had it at the 15* setting of the DMT aligner, do you mean you had it at the lowest setting or did you modify it in some way?
Click to expand...

Yea, I had it on the lowest setting with no modifications. It matched the angle the knife had from the factory according to the sharpie.
 
PC87 said:
Got this last week and ordered the Extra course stone with the kit so re-profiles would take less time. I started with an old spydie native in s30v and started to re-profile. Went through all the grits at about 15 degrees and it wouldn't shave my arm or really cut paper cleanly. So I went back and started over again with the same results.

I did put the dmt stones on the 15 degree of the SM setting after the fine stone using the browns, then the fines, but it was still dull feeling and wouldn't cut paper or any harm hair so I figured why go on the the UF's and strop.

Got frustrated and put the DMT stones on my SM rods at the 40 degree setting for a micro bevel to see if I could get it sharp that way.

After about 6 minutes going through the DMT stones, then going to the brown, fines, and UF's stones then strop, I have a hairless arm now. I mean you couldn't even hear it going through phone book paper much less feel it.

My question would be why couldn't I get that edge at the 15 degree setting on the aligner?

Thanks
Click to expand...

The edge wasn't fully apexed in the work done on the Aligner. Adding the microbevel on the SM at the wider angle apexed it. As previously mentioned, the actual sharpening angle set by the Aligner was probably lower than assumed, and would take a lot longer to remove all the steel necessary to fully apex the edge. Approaching it at a wider angle with the microbevel got you in full contact with the actual edge, so you were able to apex it there.

On S30V, even diamond hones will take quite a while, and still longer, the smaller the hones are. Using a Sharpie to indicate when you're close to apexing is sometimes helpful, but I've found it's still not quite 'proof' the edge is fully apexed. Very often, there'll still be a (literally) hair-thin stripe of ink along the very edge that gets overlooked; usually need a very bright light and a good magnifier to see it. I rely more upon doing a lot of test-cutting in paper to tell me what's going on, as I get closer to apexing. I've mentioned before, the cutting never lies about what condition the edge is in; if the edge is fully apexed, it'll become much more obvious in how it cuts (this is what you saw after microbevelling on the SM). You might still see some snagging from burrs, but the fully-apexed edge will still cut paper viciously, especially coming off of a relatively coarse diamond hone.


David
 
Obsessed with Edges said:
The edge wasn't fully apexed in the work done on the Aligner. Adding the microbevel on the SM at the wider angle apexed it. As previously mentioned, the actual sharpening angle set by the Aligner was probably lower than assumed, and would take a lot longer to remove all the steel necessary to fully apex the edge. Approaching it at a wider angle with the microbevel got you in full contact with the actual edge, so you were able to apex it there.

On S30V, even diamond hones will take quite a while, and still longer, the smaller the hones are. Using a Sharpie to indicate when you're close to apexing is sometimes helpful, but I've found it's still not quite 'proof' the edge is fully apexed. Very often, there'll still be a (literally) hair-thin stripe of ink along the very edge that gets overlooked; usually need a very bright light and a good magnifier to see it. I rely more upon doing a lot of test-cutting in paper to tell me what's going on, as I get closer to apexing. I've mentioned before, the cutting never lies about what condition the edge is in; if the edge is fully apexed, it'll become much more obvious in how it cuts (this is what you saw after microbevelling on the SM). You might still see some snagging from burrs, but the fully-apexed edge will still cut paper viciously, especially coming off of a relatively coarse diamond hone.


David
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thanks David
 
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This brings up another question,

Should I just leave the micro bevel on there if its working or is it going to be sharper without putting a micro bevel on it? Its a 20* MB and I read where guys are using 20* for their primary bevels. I am confused again now. It doesn't take much.:)
 
PC87 said:
This brings up another question,

Should I just leave the micro bevel on there if its working or is it going to be sharper without putting a micro bevel on it? Its a 20* MB and I read where guys are using 20* for their primary bevels. I am confused again now. It doesn't take much.:)
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If you're happy with how the 20°/side microbevel is working right now, I'd see no urgent reason to immediately re-bevel it (unless you want to). A crisp and fully-apexed edge at 30° inclusive (15°/side) will ultimately cut more easily. But, if the edge is working for you right now, might just wait until it needs sharpening again, then take it down to the thinner edge at that time, if you still think you want/need to.

In other words, use it for a while and see how it performs. That base of reference will be more meaningful later, if/when you decide to take it thinner and compare performance at that angle.


David
 
Obsessed with Edges said:
If you're happy with how the 20°/side microbevel is working right now, I'd see no urgent reason to immediately re-bevel it (unless you want to). A crisp and fully-apexed edge at 30° inclusive (15°/side) will ultimately cut more easily. But, if the edge is working for you right now, might just wait until it needs sharpening again, then take it down to the thinner edge at that time, if you still think you want/need to.

In other words, use it for a while and see how it performs. That base of reference will be more meaningful later, if/when you decide to take it thinner and compare performance at that angle.


David
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The knife I did this to was just a practice run for the knife I really wanted to take down to a steeper angle. Now Im thinking just to stay at the 40* inclusive with this other knife thats elmax to see how that goes. Thinking I will just start with the EC and go all the way to the fine then on to the ceramics of the SM.
 
PC87 said:
The knife I did this to was just a practice run for the knife I really wanted to take down to a steeper angle. Now Im thinking just to stay at the 40* inclusive with this other knife thats elmax to see how that goes. Thinking I will just start with the EC and go all the way to the fine then on to the ceramics of the SM.
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Considering the use of the sharpmaker I've always felt that you should put on a primary bevel of 15-18 degrees per side, then you can do touchups easily with the sharpmaker at 20 degrees per side.
 
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