Symmetrical blade grinds - How do you do it?

[Jim T]

Okay, I'm not gonna pull my hair out. I'm just gonna to ask:

How do you guys get those nice, even, symetrical grinds running along the length of your blades?

My grind line along the length of the blade is never even. There's usually a wave or two in it. Is there some sort of jig people use? Or is it simply a matter of practice, practice, practice until experience finally prevails? I flat grind if that makes any difference.

Jim

[Recurve]

That is why you wear a hat, to keep from pulling your hair out. I don't think anybody can tell you how to do it with your machines. You're correct it's practice,practice,practice. I believe comfort=precision find what is most comfortable for you with your equipment and it will come. -Jim Shull-



wwwshullhandforgedknives.com

[Ray Rogers]

I agree, practice is the most important component of that process. But, not the only component. As Jim said, being comfortable is important. In addition, using fresh, sharp belts is of major importance. Having perfectly flat parallel sides on the steel you're grinding on is also essential. That's why we own surface grinders or buy precision ground steel.

Some of it is technique: the platen (or wheel) at the correct height, feet apart, elbows in at your sides, sway your body, etc. Watch some videos of accomplished grinders and see what they do.

As for jigs, no, not for most of us. They just limit your choices in the long run, practice is far better. Try grinding some blades from strips of wood lathe. When you get to where you can grind straight lines in that soft wood you'll probably find it much easier to do the same on steel......

[Jim T]

Thanks for the advice, gentlemen. I just bought myself another hat, Jim.

I checked out the price of precision ground steel. Man, that's steep - almost double of price of the regular stuff (I've been using ATS-34). How much are surface grinders and where can you get them?

Good suggestion about practicing on cheaper material, Ray. I've got some non-knife making steel that I'll try out. Any recommednations for videos that demonstrate good grinding techniques?

Jim

[B.Finnigan]

I got sick of buying what are supposed to be the best grinding belts and have them gone after one knife. So I file all my blades. For $14-$20 I can buy a high quality file that will last for two years.

Plus I have never screwed up a single knife with a file. I would need a second mortgage to buy two years worth of grinding belts for all I do. I still use my grinder but not for too many knife related purposes.

It allows me to turn a really expensive hobby into just an expensive one.

[Ray Rogers]

Our own Gene Osborne has a series of videos that have received rave reviews. There must be a couple in there that show good grinding techniques. Gene's website is http://www.centercross.com/

BTW, today is Gene's birthday .....

[SteveA]

I was taught and firmly believed the "no jigs" approach. The problem was I just didn't make enough knives to keep up the practice. Not making excuses, if it sounds that way, I just have too many things I like to do.

At the 2009 Batson Blade Symposium, Tim Hancock presented a session on grinding that I'm still working on. He has a neat system worked out. I'd recommend the DVD that Kent put together from Tim's presentation. It's available from the Alabama Forge Council at www.alaforge.org, I think $12 or $15. In the interest of full disclosure and all that, I am an AFC member. I'm also an apprentice bladesmith who was really impressed with Tim's system.

[CWKnifeman]

One thing that a lot of people that have never seen anyone grind in person or have been shown is how to actually grind a flat. I am not trying to be uppity, but there is a process. First mark the blade edge with an industerial sharpie (it will hold the marks for about 500 drgrees F.. Mark it from both sides leaving about 35 to 40 thousands at the center part. Then starting at about a 45 degree angle grind to the center mark on one side then the other. From this point slowly grind down toward the spine taking a few degrees at a time this will come over time to where it will become natural to you ( by a few degrees I mean between 1/16" to 3/32 of an inch this will take time to learn). Slowly work your way down ti where you want the grind lines to be. first one side then the other. You may have better luck in starting with you predominate hand initially as most people have a better grind with their nondominate hand. Take it slow and a little at a time. This should help you not to have such a waveie grind line.

Another thing that may help is to use a block platten to help smooth out some of the bar stock going lengthwise on the platten bar. Use a 2 x 2" block of wood with a pin drilled square into it the size of a pin being used in the blade tang or just drill a 1/8" hole just for this purpose then useing the block against one side of the barstock grind to where the stock is flat then repeat for the other side. I have had more than one maker that I was instructing ask how did I get my stock ground down to size when I did not have a surface grinder at the time. I told them the same thing that I tell you now with a sanding block. One maker did not believe me until I showed him that I could take a 0.133" piece of steel down to 0.125" +or - 0.0005" with only using a woodblock It can be done actually mine was closer then his was using a surface grinder. What I am trying to say is use what you have and learn how to use it properly for all of the different applications that you need.
I hope that this is of some help to someone.
Curtis

[pipecrafter]

I forget where I learned it, but I grind exactly as Curtis described. The only difference is that I use a scribe to mark the cutting edge. And for really small blades, like folders, I use a couple small pieces of stainless clamped to the blade to make sure the plunge is even - but these don't really help to keep the grind straight, they just make sure I start it in the same spot every time.

Curtis, That tip about the wood block - do you have any pics? I'm having trouble visualizing that, and it sounds like exactly the method I need to use for a couple things currently sitting on my workbench.

[Jim T]

Thanks for the tips on grinding. I'll be the first to admit that I have a lot to learn and I appreciate the benefit of everyone's experience.

Curtis, I'll echo Kurt's request. Any pictures of how you use a wooden block to smoothly flatten a peice of barstock?

Jim

[B.Finnigan]

I use a 100 lbs pull magnet from HF with a layer of Gorilla tape to keep from scratching the steel. You just have to remove or saw off the eye bolt.

I have also used a piece of hardwood block with a lip that is the same height as the blade thickness. It needs to be a bit narrower so your pinky and thumb can still hold the edges of the steel.

[Ray Rogers]

Jim T

I think you should thoroughly investigate and experiment with the manual techniques given here for flattening a piece of steel. Since you asked though, new 6x12" surface grinders can be purchased from Harbor Freight or Grizzly for between $1500 and $2000 depending on catching a sale and how much shipping is involved to your location. That's a lot of money but not really any more than a good grinder, in fact, probably less. But, let that be for the future, try the manual methods first.....

[CWKnifeman]

Jim and Kurt I will post some photo's tomorrow. I actually have several with different size of pins that I use quite frequently especially if I only need to take off just a few Mill..
Thanks for the kind words I try to help out othermakers whenever I can.

Curtis

[CWKnifeman]

Here is a photo of my grinding blocks. For use my flat platten is vertical so it is fairly easy to use wheather it is a blade, spring, spacer, and full or hidden tang fixed blades.

I use wood as well as marciata for various size pieces.

Make sure that the pin hole drilled is square to the board, this also means that the board should be square. Drill and place a pin the same size as the pin being used for the blade pivot as an example. Place the blade/block against the running belt and slowly apply pressure evenly, when pulling the metal/block pull it straight towards you in one motion. Basically that is all that there is to it. It takes time and as always be safe, and always keep a tub of water at hand length to cool the material down.



Curtis

[pipecrafter]

Thank you Curtis! So simple, it's elegant!