Newbie- Flat grinding help?

Pedro G.

Well-Known Member
What i've seen is that most people say that flat grinding is a lot easier than hollow grinding. Because I'm new their both just as hard.
Now Flat grinding is the one I like best but I can't get the hang of it. My knives either end up round, or uneven in one way or the other and I can't seem to get it right?

Any tips or ideas or any info of use would be a huge help.

Thank you -Peter

P.S. I use a small Craftsman 6" belt sander for this.
 
There is not a easy way or fast way to master doing knife grinds. Yet, from what I have seen. This bubble jig will aid you alot in learning. Practice makes perfect. Keep trying and have fun!!
 
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im with randy and the two things that helped me were grind edge up and lots of light/practice
 
What i've seen is that most people say that flat grinding is a lot easier than hollow grinding. Because I'm new their both just as hard.
Now Flat grinding is the one I like best but I can't get the hang of it. My knives either end up round, or uneven in one way or the other and I can't seem to get it right?

Any tips or ideas or any info of use would be a huge help.

Thank you -Peter

P.S. I use a small Craftsman 6" belt sander for this.

ther is a quick and easy way to flat grind....just review my post and look closely at the photos....randy.
http://knifedogs.com/showthread.php?12190-my-first-build....&p=116853#post116853
 
HHH Knives: Thank you very much, I will keep practicing and will take a look at your post.

Franklin: Thank you for the tip, I will work on it.
 
without going too in depth, this is just a rough overview of how I flat grind:

1. Scribe two center lines about a dime's thickness apart in the middle of your blade, from the ricasso (or where your plunge lines will be) to the tip of your knife.
2. Mark your ricasso/plunge line area (where your flat grind is going to stop before you get the the handle). This can be done using a marker, wrapping some masking tape around the blade, using a file guide, etc....
3. Bevel the corners off the edge of your blade at 45 degrees and grind JUST until you hit your the scribe line closest to each side of the blade. Bevel at this approximate angle from the area where you marked your ricasso all the way to the point of your knife. Getting exactly 45 degrees isnt important so much as grinding an agle that's somewhat shallower than what your final flat grind angle will be.
4.Once you've beveled approximately 45 degrees to your scribe lines, you can't start working on your flat grind. Start by tilting the blade against the belt until there is just a small bit of space between the belt and your scribe line (or where your 45 deg bevel stops at the top edge of your blade. Make a couple of passes until you are about to touch your scribe line again, and tilt the blade back towards you until there is more space between the belt and your scribe line again. Repeating this process will gradually cause your flat grind to lower towards the spine of your blade.

Just make sure you keep the knife at a consisten angle as you are making your passes, and try to keep the same amount of space between the belt and the scribe line with each pass so you don't grind a belly in the blade.

I know this is kind of hard to explain without pictures, or without showing you in person, but maybe it will make sense.
 
ARcustomknives: Thank you very much it is actually very helpful, but although these are really good and clear instructions I can't seem to get some things as in what a bevel is and what I do after that and is all the angling a guess?
 
Pedro - I take "bevel" to mean the angle of the grind - any angle. Andrew's notes look good to me. I do it a little differently, and your combination of tools, lighting, and your preferences = try some variations and see how they work for you in your shop.

That said, I'll throw in a few things:
(1) Lighting - I can't tell if I'm holding the knife at the angle I'm shooting for if I don't have good multiple sources of light. Lots of it.
(2) Flat against the belt - place the blade lightly on the belt so that the full width of the belt is in contact with the blade - then and only then press more firmly. Otherwise you will get kind of a wavy, corrugated grind. Once you establish the desired angle of the grind then the blade will "seat itself" when you place it lightly on the belt before pressing firmly. Greg Neely drilled this in at the intro bladesmithing class and it works great!
(3) Jigs - I don't get along with 'em - I bought several at first and eventually tossed them all in a drawer. Even the grinding table - tore it off the belt grinder and threw it in the drawer. I like freehand grinding - but that's just me. Jigs work great for lots of makers that are a whole lot better than I am!
(4) Lock your wrists and elbows and move the blade across the belt by shifting your weight from one foot to the other. That's a little bit of an exaggeration but not much. If you've ever taken Tai Chi or a similar discipline, use that slow steady flowing movement to move the blade.
(5) Full strokes - Wayne Goddard drilled this one into me: start at the plunge line and don't stop until you are at the end of the blade.
(6) Wide focus - my biggest early challenge was not watching the big picture. I'd focus on one small area and the belt would be grinding away some other part of the knife that I really did not want to loose!?!
(7) Fat markers and lights. More lights. When you go from a course grind to a finer grind you can get a good idea of where you need more work by using a fat marker to "paint" the blade and as you grind with the finer belt you can see where you are hitting, missing, and the course scratches that you have not sanded out yet.
(8) Hand sanding a flat grind on a flat board. When doing the final hand sanding on a totally flat grind I put a board (chunk of Micarta in my case) in a vice, clamp sandpaper tightly to the board, and move the blade across the board/sandpaper - somehow this gives me a better totally flat surface than holding the knife still and rubbing the sandpaper across it. This was another hint from Wayne.
(9) Practice. It's frustrating at times and rewarding at times - gradually I learn to avoid the screw ups and turn the good practices into muscle habits. And if you get the chance, watch a good knifemaker in action. In the flesh. Videos are nice, but not the same.
 
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Pedro,
Fred Rowe's Bubble jig is worth every cent! I don't think it is as much a crutch as it is a learning tool, I told Fred this myself, the more I grind with the Bubble Jig, the less I find I need it, there are times when I do, like when I change thickness of steel from my norm, being blind in one eye, my depth perception is awful, the jig allows me to keep a constant angle that I couldn't normally keep with out it. The more I use it the better I get, the less I need it, thats why I say it is a learning tool. Sure there are those that spout off about grinding free hand, and if they can that is great! But if I can't, I'm supposed to quit? Heck NO, I got me a bubble jig and I make knives!!!! Sure you can grind up a couple tons of steel and a couple thousand bucks worth of belts to learn how to free hand, or you can get a tool that will help teach you how to do it, I'm all about easier, working smarter not harder, is what my grandaddy always said, and he was a smart fella for someone who couldn't read or write, made the best shine from what I'm told, too! Rex
 
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Michael Kemp: Those are some great tips Michael, Thank you, ill work on those, but it hasn't hit that part of the brain yet. I'm more into simple when it comes to instructions. With that in mind, Is flat grinding a blade simply creating grinds to the scribe lines and slowly working down into smaller angles until you've reached the spine? That's what i'm understanding right now.
Thank you very much

Rex: Thank you very much and I can tell that bubble jig is extremely useful but i'm broke right now and when I do get money i'm looking to finally buy a tank for my plasma cutter or make myself a forge. I'm trying to sell a Co2 tank and another smaller tank. So if I have any money left over I will definitely look into getting a Jig and if you know anyone that is selling a used one please fill me in.

Thank you very much :)

-Pedro
 
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wow Kemp pretty good i was thinking you can also start by practising on a thin piece of wood Ive herd of guys teaching that way just to give them a feel for what they are going to do. they do a design of a knife then mark center line then try to grind out just like you would do any knife and you get a feel for what the design will feel like at the same time then you will see if you shoul change anything before you start the real one. the grinds are the angle from the two scribe lines to how far up to the spine you want to go that depends on you and the design
 
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Alot of sound advise given here.

I'll add that a SHARP belt and FIRM pressure are key to keeping your flats flat and not faceted. A dull or loaded up belt will want to wander off your flat and give you alot of greif.

If your stock removing when you first start grinding and you've got a very small flat it'll be more difficult to stay on it. The higher (and wider) your flat gets the easier it is to stay on the flat reducing mistakes.

The 3 most imoprtant tips for learning to grind- 1. Practice 2. Practice 3. Practice

I think for most learning to grind is an evolution of progress more than a "Eureka I've got it" moment. Keep at it and it will get better.

The thing that held me back the most in the begining was not knowing when a belt had reached the end of it's usable life and trying to push them WAY too far.

One of the best things I've heard said (or written) about learning to grind-
"Put the steel to the wheel" - Tai Goo In your case though it'll be more like- put the steel to the platen

Take care- Josh
 
Franklin: That is a very good idea, Thank you.

Josh Dabney: Yes i'm going to save this thread for future reference because the information here is priceless. Thank you for the tips, I will use them.

- Pedro
 
This thread is very informative. I just thought I would add my 2 cents worth. I noticed an improvement in my own flat grinds after adding more light to the setup. I also noticed an improvement after adjusting the height of the grinder (I had been grinding at about chest height and saw an improvement after moving it to just about belly button height.)
 
bjohnson: More light is something everyone seems to agree on so that is one thing I am sure to fix. Thank you :)

-Peter
 
Michael Kemp: Those are some great tips Michael, Thank you, ill work on those, but it hasn't hit that part of the brain yet. I'm more into simple when it comes to instructions. With that in mind, Is flat grinding a blade simply creating grinds to the scribe lines and slowly working down into smaller angles until you've reached the spine? That's what i'm understanding right now...

-Pedro

That pretty much sums it up how I was trying to explain it Pedro. And for that matter, you don't even have to work all the way down to the spine if you don't want to.

I may see if I can make a video if I ever get anytime out in the shop. As far as "precise angles" are concerned, I couldn't begin to tell you want angle I flat grind at. It just depends on where your centerlines are, and how wide and thick your blade is. I don't worry about angles so much as I worry about keeping my lines even on both sides, and keeping everything straigh and centered. The angles tend to "work themselves out".

You just want to make sure you're using even pressure, and keeping the blade at a consistent angle with each pass.
 
ARcustomknives: Thank you very much I would really appreciate that, and that is something I am trying to do while I grind (Keeping it even.)

-Pedro
 
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