DMT D8XX 120 micron stone!

T

thombrogan

Joined
Nov 16, 2002
Messages
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My particular one is defective (missing some diamond on one side), but still, this stone cuts faster than a 1" x 30" belt-sander with a fresh 50 grit aluminum oxide belt, an 80 grit waterstone, and an 80 grit wet-grinder wheel. It cuts slower than the sander with a fresh 36 belt or a 36 wheel on the bench grinder, but leaves a better finish and is lots more temper-safe.

This afternoon, I changed my previously self-hawkbilled Yojimbo back into a wharnie. I only have the before pic now:

hawkjimbo1.jpg


Reflattened the cutting edge and left it with a waifer-thin relief grind in about 20 minutes. For the amount of metal removed, it impressed the heck out of me. Can't wait to do more.

Thanks, DMT!
 
Thanks Thom for the report on the DMT. It's going to be my next stone very soon.
 
Waiting for Lee's Canadian source to deliver first, I hope. ;)

I might start selling off stuff to get a second one myself.
 
Do you have the regular x-coarse DMT stone?

thombrogan said:
... this stone cuts faster than a 1" x 30" belt-sander with a fresh 50 grit aluminum oxide belt ...
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With the power on?

-Cliff
 
Yep, with the power on. It is likely that my $30 sander may have a weaker motor than other sanders.
 
Are you pressing really light? Is this on the platen or in the slack region? One of the problems with trying to grind fast with belt sanders is on thin blades with no heat sink ability. Impressive though, I don't go beyond 80 grit belts and they blow by the 200 silicon carbide stone I have for regrinding many times to one, just a matter of belt speed vs my hand speed. I press way harder on the waterstone, 75 lbs or so, this would burn the edges on the sander way too quickly, if everything was HSS this would not be so much of a problem. Just break out the angle grinders. I should compare the cutting speeds the next time I have to reprofile doing each side. I have a x-coarse DMT but you have to go so light it is similar in cutting speed to a 800 grit waterstone pressed very hard.

-Cliff
 
Cliff Stamp said:
I have a x-coarse DMT but you have to go so light it is similar in cutting speed to a 800 grit waterstone pressed very hard.
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Why do you have to go light? On a well-bonded diamond stone (such as DMT or EZE-Lap), it shouldn't be a problem. The poorly-bound diamonds, which make the stone feel coarser than the indicated grit, will fall away, but the remaining stones should stay for a long time even with ludicrous pressure. They have on my 1" x 6" 150x EZE-Lap.
 
I used a dual sided Ez-Lap years ago fairly hard and it quickly went very smooth. DMT warns about excessive pressure and there are frequent comments on the forums about quick wear out so I always went light on the DMT's. How hard do you press on yours?

-Cliff
 
I'm very interested in how hard to press with diamonds. I've also read the reports of them waring out and diamonds being stripped, but also have read of people pressing hard and not haveing the diamonds ware out of the hone. It's one of those 50/50 things based mainly on reports. I personally have only 2 small DMT plates a coarse and a fine and by touch they feel the same but they do cut different. As they are a part of the clamp and rod system they were used with pretty good pressure but not real hard, lean on it hard. No problems with them, however I don't use a clamp system any more and haven't for a few years so cann't say how they would have held up long term.
edited to ad..
By feeling them, touching with your hand/finger, they do feel smooth and like each other but they still cut away steel very well.
 
Ben Dale constantly warns about diamonds wearing out with the Edge Pro. Only Goddard is consistently less positive about diamonds.

-Cliff
 
We'll burn that bridge when it occurs. Hopefully soon. :D

Here's my reprofiled Yojimbo with the edge slightly cleaned up:
rewharnied.jpg


Sorry for not answering your earlier question about the platen, Cliff, but I don't use it too often. Too loud and, for sharpening, gives too much vibration. The point on my Yojimbo was surprizingly sturdy before I resharpened it and then I chipped it off on the platen. :mad: So now I'm a slack-belt enthustiast.... :o
 
I have heard that about the platen before, not on issue on mine. I guess I lacked out on my ultra elite $50 model, or I am just not sophisticated enough to notice. Interesting handle design, any comments?

-Cliff
 
Yeah, if you get frequent dermatitis in your fingers, choose from a million other great Spyderco designs. Otherwise, it's one of the best handles I've used. It allows for a variety of hand grips, but is great for the designer's favorite grip (hammer with thumb on spine).

Now a $50 sander is what I should've got, but my mean machine plays nice if I no-touchem the platen and lets me use 1/4" x 30" belts for wildly curved blades.
 
That is pretty impressive, Thom, considering that we are talking about an S30V blade. Did you have this blade rehardened by Wilson aswell?

Cliff, the handle works quite well. Especially choked up, it offers a lot of control. With the index finger in the big choil I would wish for a little purchase towards the thinning butt, but it is still ok. It is very safe because of the deep cutout. There are certain grips, were I really don't like the concave curve of the back of the hand. In other grips it works particularly well. In my opinion there is only on thing completely misplaced on this handle: the indexing hole/dimple is way to far toward the butt end. I would have liked the dimple about 3/4" further up.
 
HoB said:
That is pretty impressive, Thom, considering that we are talking about an S30V blade.
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This is one of the many times I would like to either live close by or have at least a video connection as experiences differ so rapidly. I used my x-coarse DMT to reprofile one side of a Jess Horn in ZDP-189 to a uniform 12 degrees. It took about a thousand passes on the stone, I was also pressing fairly hard, about 25 lbs (used scale). I then used a 200 grit silicon carbide waterstone to bring the other side flat with the primary grind in about two minutes. Which included the time spend cleaning the crud off the knife periodically to see what needed to be reground. I was leaning into the waterstone really hard, about 75 lbs and it chewed through the steel. I am going to see if I can get a hold to DMT and see if they recommend using their pads at such a high level of force.

There are certain grips, were I really don't like the concave curve of the back of the hand.
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This is what I was thinking, general versatility as the underside looks kind of pointy. Generally why do you carry it vs something like the Paramilitary (grip wise) ?

-Cliff
 
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