DMT Aligner

S

Swedge

Joined
Dec 23, 2008
Messages
334
I just got a DMT Aligner kit, one with four stones. The instructions leave much to be desired IMO.

The angle chart refers to "blade width." Are they referring to the distance between the edge and the spine? I assume so, but what if the blade tapers and that distance varies? Where do you measure to come up with the width?

Do you push the spine of the blade into the clamp until it stops? Or do you try to have the edge of the clamp in the middle of the blade (between the spine and the edge)?

Do you position the blade into the clamp as close as possible to the handle? The diagram suggests that, but the text suggests the middle of the back of the blade.

Do you have to match the stone to the bevel, or can you simply rest the stone on the edge once the adjustment rod is set and then stroke the edge with the stone?

If you have a short blade, say 3" long, do you need to move the stone in the zig-zag pattern suggested by the instructions, or if the stone will cover the entire edge in one stroke, can you just stroke the stone across the edge while moving the outer end of the stone toward the edge of the blade?

Any tips welcome.
 
There are stop tabs that prevent the spine of the blade from going very far into the clamp but you want the spine to be all the way back to those. I have found it best to get the clamp as close to the middle as you can or with larger blades you will get a wide bevel at the tip. Setting the angle comes down to what you like and how you want the edge to perform. Unless you match factory angles and those factory angles are perfect (usually not the case) its better to just set your own.

Use light pressure, use even strokes per side, hold the guide rod in one point so you angle is strighter and work the edge enough with your coarsest stone.

Its a great tool, I use it with my DMT benchstones when I want perfection.
 
knifenut1013 said:
There are stop tabs that prevent the spine of the blade from going very far into the clamp but you want the spine to be all the way back to those. I have found it best to get the clamp as close to the middle as you can or with larger blades you will get a wide bevel at the tip. Setting the angle comes down to what you like and how you want the edge to perform. Unless you match factory angles and those factory angles are perfect (usually not the case) its better to just set your own.

Use light pressure, use even strokes per side, hold the guide rod in one point so you angle is strighter and work the edge enough with your coarsest stone.

Its a great tool, I use it with my DMT benchstones when I want perfection.
Click to expand...


I agree with knifenut1013 on all those points.

One additional suggestion, cut a piece of inner tube or leather to put between the guide jaws and the knife surface to prevent scarring the knife and to also prevent movement within the guide. When your done sharpening, open the jaws completely before removing the blade with the material still in contact with the blade and peel it off.
 
Native Justice said:
I agree with knifenut1013 on all those points.

One additional suggestion, cut a piece of inner tube or leather to put between the guide jaws and the knife surface to prevent scarring the knife and to also prevent movement within the guide. When your done sharpening, open the jaws completely before removing the blade with the material still in contact with the blade and peel it off.
Click to expand...


Masking tape works good too.
 
Thanks for the tips.

1. Let's say you have a short blade. In my case, I am practicing with a blade that is 2-3/4" long. Should I move the stone in the zig-zag pattern suggested by the instructions, or since I can cover the entire edge in one upwards and outward stroke, can I just stroke the stone once, starting at the choil and moving all the way to the tip, and then come back to the choil and repeat? The diagram on the instructions suggest that I should start at the choil and not go all the way to the tip, but that may be for longer blades.

2. "hold the guide rod in one point"

Not clear on what that means.
 
If you can make it in one pass then do it that way, it will work any way you do it though. Always complete the sharpening stroke to the tip of the blade, do not stop short. Choil to tip and back again will work very well.

Because there is play in the space that the guide rod passes through if you do not hold it down slightly you could end up with uneven angles. When I hold the stone I place my thumb, middle, ring, and pinky fingers on the stone and my index finger applies pressure (very light) to the top of the rod. I also hold the rod to the back corner of the of the opening so the angle is more consistent, I do not let the rod slide in the opening.

When you first start using it, its very easy to use too much pressure and ruin a stone, its how I ruined my X-coarse stone. Always remember to not push too hard, sometimes it dosen't feel like its doing anything but it really is. A light touch is the key with diamond stones.

Keep a wet rag handy and wipe clean the finer stones often, they tend to clog if you don't.
 
The DMT set up you attained is a great little inexpensive kit...Have used it many many times in hand and also with benchstones.

Good points already made above and you will get used to it with use and have no regrets

Keep the stones wet and/or wiped with use very light pressure....let the stones work for you and they will last a good while. :thumbup:
 
knifenut1013 said:
If you can make it in one pass then do it that way, it will work any way you do it though. Always complete the sharpening stroke to the tip of the blade, do not stop short. Choil to tip and back again will work very well.

Because there is play in the space that the guide rod passes through if you do not hold it down slightly you could end up with uneven angles. When I hold the stone I place my thumb, middle, ring, and pinky fingers on the stone and my index finger applies pressure (very light) to the top of the rod. I also hold the rod to the back corner of the of the opening so the angle is more consistent, I do not let the rod slide in the opening.

When you first start using it, its very easy to use too much pressure and ruin a stone, its how I ruined my X-coarse stone. Always remember to not push too hard, sometimes it dosen't feel like its doing anything but it really is. A light touch is the key with diamond stones.

Keep a wet rag handy and wipe clean the finer stones often, they tend to clog if you don't.
Click to expand...

When you say "back corner" are you referring to the right or left side of the opening. I just got the aligner as well, and your tips are very helpful.
thanks!
 
I guess as long as your holding it down it really dosen't matter but I like to hold it in the back corner (near the handle) because I feel that the less the rod moves the better the angle.
 
I am having problems figuring angles with the DMT. The angle chart refers to "blade width." Are they referring to the distance between the edge and the spine? I assume so, but what if the blade tapers and that distance varies? Where do you measure to come up with the width?

I would like to to set up the DMT so I can get a 30° or 40° angle (or thereabouts) on my knife blades. Once I reprofile an edge, I would like to be able to use the SharpMaker for quick touch-ups, particularly since I have the extra-fine SM stones.

How do I set up the DMT so I can get a predicted angle?
 
Swedge said:
I am having problems figuring angles with the DMT. The angle chart refers to "blade width." Are they referring to the distance between the edge and the spine? I assume so, but what if the blade tapers and that distance varies? Where do you measure to come up with the width?
Click to expand...

It's from spine to edge, yes. It shouldn't matter whether it tapers or whatnot, because the distance from spine to edge on that axis will still be the same.

Swedge said:
I would like to to set up the DMT so I can get a 30° or 40° angle (or thereabouts) on my knife blades. Once I reprofile an edge, I would like to be able to use the SharpMaker for quick touch-ups, particularly since I have the extra-fine SM stones.

How do I set up the DMT so I can get a predicted angle?
Click to expand...

You can do it according to the chart included with the aligner. Honestly, you don't need a precise 30˚ or 40˚. If you want it thin, do it thin. If you want it thick, do it thick. If you want to maintain it on the sharpmaker, do less than 40 (to use the 40 setting for touch-ups), or if you want 30, do less than 30.
 
I use setting 6 for almost everything unless I want it a bit thicker then I will use setting 5.
 
I'd be very happy to go to an angle lower than the 30° and 40° SharpMaker settings.

The practice knife I've been using has a blade that is about 1/2" wide. Therefore, the edge doesn't protrude very far from the jaws of the clamp.

When I used the 6 setting, I was scraping the plastic on the clamp portion of the aligner. Upon inspection, I could see that if I held the metal rod of the stone holder against the upper part of the rectangular opening of the clamp, the stone would just clear the jaws of the clamp, but any wobbling of the rod in the opening would cause the stone to scrape the plastic.

When I used 5 as the setting, the stone would clear the jaws all the time, but when I stroked the blade on the SharpMaker at the 40° setting, it seemed to be rubbing the shoulder of the edge.

It would appear that based on the geometry of the device, the DMT depends on the blades being a minimum width to get, say, a 30° angle and thus do not work well for this purpose with narrow blades. The clip point blade that I am having trouble with is a little less than 1/2" at the choil and a bit more at the point where the clip point begins.

Am I wrong in my understanding of the DMT aligner? Any workaround?
 
Swedge, your stated issues with the DMT clamp are the reasons I normally use my DMT hones with a GATCO clamp that I already had on hand for several years (from an old Edgemate).
I find it to be a better setup. (I've read of others doing the same with a Lansky clamp.)

Doing it this way I'm able to utilize a more acute angle with less grinding down of the clamp's jaws.
 
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