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Edge Thickness

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Hello just wondering what some other makers are grinding down to, final rough grind before quench then your final grind b4 finishing and sharpening. I'm workiing on a 10 inch blade 1 3/4 " by 03/16 stock and cant quite get thin enough to cut rope in one swing. Doing a flat/convex grind,,its sharp, but not sharp enough, I normally dont make a blade over 6 inchs long so these big blades are challenging.

Thanks Chad

 
Posted : 12/11/2011 4:46 pm
Posts: 51
Trusted Member Journeyman Bladesmith (5yr)
 

Chad,

Since this is my first post I hope I'm not stepping on anyone's toes. But it sounds like you have a problem with your final grind, and not with your grind before heat treat. When I started out I would grind to the thickness of a dime. Roughly just over .040 of an inch. The more skilled and knowledge about ht I became the thinner I was able to grind on rough grinding.

The reason I say it's your finished edge is that I've been able to cut rope with an edge that is basically beveled from 3/16 of to sharp in under a 1/8 of an inch. Basically an axe grind on a ten inch blade.

I hope this helps.

Dave from Diller

 
Posted : 12/11/2011 7:47 pm
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New Member Guest
 

well, I can shave hair with it and slice paper forever, and slice through dry leather AFTER the 1x6 poplar board chop, just cant whack a rope in half.

my final belt grind is sharp enough to cut your finger, then I run a small bevel with a dull belt on my 1x30 to set angle then to the norton stone. My small and mid skinners and hunters are razors, Like I said since theres no call for large knives around here I never make them so I'm a little lost on the geometry with a 10 inch blade. I guess I'll take the mid section down some more to the edge

 
Posted : 12/11/2011 8:40 pm
Posts: 203
Estimable Member Journeyman Bladesmith
 

Rope cutting can be a bit tricky, so it is possible that the knife is fine.

 
Posted : 12/11/2011 11:03 pm
BrionTomberlin
Posts: 1675
Member
 

Hello Chad, like David and Allen said it maybe your technique. It sounds like the knife is sharp enough. I would suggest trying different angles on cutting the rope and try to snap your wrist forward as the blade contacts the rope. Believe me I was horrible at cutting rope, just ask Jim Crowell and Mike Williams, but through practice I am getting better. There is a a lot of technique involved. By the way on big blades I usually go down to .025 and on hunters closer to .020.

Brion

Brion Tomberlin

Anvil Top Custom Knives

ABS Mastersmith

 
Posted : 12/11/2011 11:26 pm
Posts: 0
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thanks guys, my arm is sore from swinging, and this may be some super tough rope as well its been hanging in a barn for years.

 
Posted : 13/11/2011 8:41 am
Posts: 51
Trusted Member Journeyman Bladesmith (5yr)
 

As far as rope cutting goes. Try not to come in at a ninety degree angle. Lay your knife on the hanging rope. Almost parallel with the rope give it ten degrees and cut downward, with a snap.

Always practice safely. Make sure to use a lanyard and lead with your dominant leg and keep your free hand out of the way.

Dave from Diller

 
Posted : 13/11/2011 4:56 pm
Posts: 65
Trusted Member Journeyman Bladesmith (5yr)
 

Hi Chad, I find a slightly toothy edge will more easily grab and cut rope than a smooth shaving type edge.

 
Posted : 14/11/2011 7:00 am
Posts: 209
Estimable Member Journeyman Bladesmith (5yr)
 

Chad

I would also tend to agree that is may be your technique. I had trouble getting the rope cutting down as well. To add to what has already been posted, here is what I do. I aim for a spot in the air past the rope. When I swing the knife, I am going for that spot and I just let the knife go through anything else that is in the way (rope, air). I know it sounds stupid, but if I aim for the rope, it seems like I just cut 3/4 the way through it.

Brian

 
Posted : 14/11/2011 10:47 am
Posts: 0
New Member Guest
 

Thanks Brian, I just watched your vid of cutting on youtube,, but I went and got my caliper and my edge bevel is a little too thick .029 I'll bring it down to about .023 or thinner resharpen and try again, but it will have to wait because I've got some chainsaw chain billets to finish up as well as a couple of belt axes for christmas. Thanks to all that offered their help and opinion

 
Posted : 14/11/2011 5:35 pm
Posts: 0
New Member Guest
 

Chad, When I was building my test knife I also was having all kind of problems with the Rope cut. I was able to do all the other things required just fine. But that darn rope cut just was kicking my tail. When I was discussing this with Brian Thie. He aready knew it was my technique. He suggested to me use a smaller dia rope until I got the angle of cut. That I needed to make a successful cut. Then go to the 1" Rope. Brian's thought's at looking past the rope is spot on. My point of finish was the point of my blade toward the floor in front of me.

good luck.

Bruce

 
Posted : 14/11/2011 6:49 pm
Posts: 71
Trusted Member Journeyman Bladesmith (5yr)
 

|quoted:

well, I can shave hair with it and slice paper forever, and slice through dry leather AFTER the 1x6 poplar board chop, just cant whack a rope in half.

my final belt grind is sharp enough to cut your finger, then I run a small bevel with a dull belt on my 1x30 to set angle then to the norton stone. My small and mid skinners and hunters are razors, Like I said since theres no call for large knives around here I never make them so I'm a little lost on the geometry with a 10 inch blade. I guess I'll take the mid section down some more to the edge

Sounds to me like it is just to smooth of an edge as mentioned above. Try a pass on a 400 or 600 belt and strop it on leather with white buffing compound. Also I find My best cuts are done with a backhanded swing left to right with my right hand at about 45 degrees angle. Hope this helps. Paul

 
Posted : 14/11/2011 6:58 pm
Posts: 0
New Member Guest
 

Well I brought the edge down some more,1/4" up from edge is .104 and edge is .024, resharpened,,,,,,,,,,,,,and the first swing sliced it like a hair,, thinner edge plus the straight down follow through swing method. I stared at the fell piece for like a minute in disbelief.

 
Posted : 20/11/2011 3:50 pm
Admin_DJC305
Posts: 1999
Member
 

Congratulations Chad! Great job! It is a good feeling seeing the rope hit the floor after being cut with a blade that you hand forged.

Thank you to the Master Smiths, Journeyman, and Apprentices that were so willing to share their knowledge to help you to learn this technique. Bill Moran founded the American Bladesmith Society for the sharing of information about the forged blade and that is exactly what our members are doing.

Dan Cassidy
Journeyman Smith
Send an email to Dan

 
Posted : 20/11/2011 6:17 pm
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