uneven edge thickness, cuz ima noob...

[OccamsBlade]

So, I'm on my 3rd attempt at making a blade. The first one, a kitchen knife, came out okay. It's at least usable. The second one is unfinished mostly because I'm already seeing the limitations of my 1x42 belt grinder. Anything over a couple of inches in length, and over an inch in width, will bang into various parts of the grinder on one side. The current blade I'm working on is coming out quite well, as I'm using a piece of 3/16 scrap that is about 2 3/4 in length (stick tang).

The issue I'm having is keeping an even edge. I'm able to get clean plunges/bevel, but when I try to correct for uneven thickness on the edges, I end up screwing them up. I'm usually able to clean it back up by pushing the plunges/bevels back more than I intended, but the uneven thickness on the edges still remain. For example I have about .04 on the heel and tip, then on the belly I have about .01 thickness. I know it's just my lack of skill and inexperience, but is there a way to correct the unevenness without screwing up the crisp bevels I somehow managed to get? How would you guys fix it?

I'll put up a pic as soon as my camera battery gets done charging.

 

[JTknives]

It's all practice. Did you scribe lines where you want the edge to be. Incomes down to fealing the grind. When grinding you can control what is ground by where you apaly the pressure. To Even up the edge and take it to the scribed lines I grind like normal but I put pressure on the edge not the spine. I do this by twisting the tag a little and pushing it with my thumb on my supporting hand. Normaly this will keep the edge bevels in tact but like I said befor it's all practis.

 

[HomeBru]

JT has it, mark your lines and practice, practice, practice. So much of it is figuring out how your tools remove steel. Practicing on thin pieces of wood (Think paint stirring sticks) will give you an idea of how to move your hands and where to put pressure.

If you're fighting inferior equipment in addition to not having a handle on the process, it's going to make your learning curve much steeper. It can be done, but it's a lot harder.

 

[OccamsBlade]

Yeah, I scribe where I want the bevels to go...but those usually get pushed back further because of my minor screw ups. Just the slightest little jerk or pressure turns into a big mess by trying to go back and correct them. I usually do end up fixing them, but the initial scribe lines are far gone by then, haha. The ones on the flats at least. Yeah, The hard part is getting the right angle so that they both connect so to speak.

I will be getting a real belt grinder soonish. But right now I'm hemorrhaging money with my last quarterly tax payment, and electrical work on the house.

Taking some more measurements on the blade, it looks like I'm about a millimeter deeper on the belly part of the bevel. So I'll need to take a millimeter more off the heel and tip. So I just need to grind the heel and tip until they are the same depth, then go back and grind it from heel to tip to get it all nice and even. Of course that's in theory....in practice it's a whole other story for me, haha. Yup, practice, practice, practice. Although I'm seeing improvements with each blade I do. I guess that's what counts.

Here's a (blurry) pic...before I destroy my bevels altogether

 

[OccamsBlade]

So I guess it could have been much worse. After a rolled edge, and a couple of gouges, I only lost about 2mm on the belly and about 1mm on the tip. It has slightly less of a belly as a result, so messed up the profile I was going for, but should be serviceable. Just waiting on some 120 grit belts before I heat treat it, it's at 60 grit atm.

Starting to feel the subtleties, like slowing down and applying a bit more pressure at the tip when I want more control, and material taken off. Tips are tricky. Also when at the tip, it's best to pull towards me quickly when I'm done with the pass, instead of continuing to the side. Seems like there's less chance of screwing up the tip when I do it that way.

 

[john april]

if you got a rolled edge meaning the belt ran over the edge because you could not hold the knife still, that is because you are putting too much pressure against the belt and it is grabbing the blade and pulling it down. use less pressure. i used to do this all the time lol. the closer you get to your target lines or scribes, the less pressure you should use. this way if you make a mistake, it is minor.

 

[S.Alexander]

Yeah, I scribe where I want the bevels to go...but those usually get pushed back further because of my minor screw ups. Just the slightest little jerk or pressure turns into a big mess by trying to go back and correct them. I usually do end up fixing them, but the initial scribe lines are far gone by then, haha. The ones on the flats at least. Yeah, The hard part is getting the right angle so that they both connect so to speak.

I will be getting a real belt grinder soonish. But right now I'm hemorrhaging money with my last quarterly tax payment, and electrical work on the house.

Taking some more measurements on the blade, it looks like I'm about a millimeter deeper on the belly part of the bevel. So I'll need to take a millimeter more off the heel and tip. So I just need to grind the heel and tip until they are the same depth, then go back and grind it from heel to tip to get it all nice and even. Of course that's in theory....in practice it's a whole other story for me, haha. Yup, practice, practice, practice. Although I'm seeing improvements with each blade I do. I guess that's what counts.

Here's a (blurry) pic...before I destroy my bevels altogether

I think what JT was referring to, is to scribe the lines on the edge of your blade, where you want the edge thickness to end up. I do this the simple way. I mark my edge with permanent marker. Then I use a drill bit that is one size smaller than the thickness of the blade steel, and scratch along the entire length of the blade edge. Flip the blade over and scratch it again. This will give you two lines that you can focus on grinding down to, and will keep everything nice and even.

 

[OccamsBlade]

Right, I do the exact same, as well as scribe lines for how far back I want the bevel to go. I was just saying that I have a hard time getting a primary bevel that meets up with the scribe lines on my edge to the scribe lines on the flats. I usually end up taking off more material at the top than on the edge. So I guess I'm just getting the angle wrong, and not correcting it enough towards the edge as I go along. I'm more afraid of destroying the edge/profile than anything. I'm extremely design oriented...which at this point in the game is to my detriment, haha.