Help with Flat Grinding

Will not work with a curve in anyway. In reality it can only happen on two perfectly flat plane and come to a tip with a constant angle edge. A perfect angle with the spine one leg.
Put a precision straight edge on one of your perfectly flat curved blades and you will see it is not perfectly flat. No way. You can only have a curve with slightly "bowed planes"
You can be close but never flat with a curve. Does not mater if a circle or a portion of an oval. Sorry.
 
ib and all,

My apologies. The intersection of the planes forms a straight line and not a curve as I posted in error earlier. I guess I was stuck on the idea. Thanks for keeping me straight, ib.

Brett
 
O.K., Guys, just got back from a "short" evening at work. Disclaimer: The brain's not working full-capacity right now. (And, maybe that's not a bad thing at this point).
This is what I got so far:
1.) A flat grind is not really flat, especially at the belly, where it's actually made up of a whole lot of really small angles.
2.) If I want to have an alleged "flat grind" along the belly, I'm going to have to either: a) lift the butt of the blade away from the grinder, or b) "turn" (rotate) the butt either up or down, while grinding the belly, depending weather (sp?) I'm grinding edge up or edge down.
3.) If all this wasn't tricky enough, I'm probably also going to have to "twist" the blade while grinding the belly.
4.) It seems like the belly is the whole problem to flat grinding, because it's a curved surface.
Do I have these points down? If not, please somebody set me straight.
Thanks a million,
Mitch
 
Ryan Minchew said:
Troop I may have missed it in an earlier thread, but did you say where you are from? I live in the Texas panhandle and would be glad to show you if you were close enough. I'm not saying my grinds are perfect, but a few months ago everything just clicked while grinding and I could show you to get you a good starting point. I'd try to explain it but I think I would confuse us all.
Click to expand...

I appreciate it big time, Ryan, but I'm up in the Land of the Lost Souls (New Joisey). Thanks anyways,
Mitch
 
Don't overthink it, Mitch. Practice, and the motion will come to you. Try coating your bevels with with one of those big, fat magic markers periodically once it's "close to final" and watching how the grind progresses. Keep working it towards the tip. Your hands will learn.
 
Mitch,

I think you should just give up now. I'll give ya' $300 for the KMG and we'll call it even :D Seriously, it took me forever to get the motion and I still have to "fix" my grinds. The best thing is, now I CAN fix them instead of having another paring knife when it was supposed to be an 8" blade :)
 
Sounds like you've got the idea down pretty good now.:thumbup: The only thing left to do now is turn some steel into dust.:D

It really is alot easier than it sounds once you get going. Just Practice Practice Practice.
 
Never had to break out a slide rule, calculator or computer program to grind my knives, just stuck em on the belt until I thought they looked right. Of course, that might be another problem for me ;)

Troop, I can't tell you how to flat grind cause I don't do it well myself. I can tell you that you will probably be happier if you learn how to grind edge up. Lot easier to grind to a line when you can see it.

By the way (some folks won't agree here), most of my better flat grinds are hollows first. I like to hollow grind my blade because it's quicker and painless-er. It's just plain easier for me. It's not too bad to flatten a hollow grind, even if you make it on an 8" wheel (although it's a little nicer on a 14).
 
AcridSaint said:
Never had to break out a slide rule, calculator or computer program to grind my knives, just stuck em on the belt until I thought they looked right. Of course, that might be another problem for me ;)

Troop, I can't tell you how to flat grind cause I don't do it well myself. I can tell you that you will probably be happier if you learn how to grind edge up. Lot easier to grind to a line when you can see it.

By the way (some folks won't agree here), most of my better flat grinds are hollows first. I like to hollow grind my blade because it's quicker and painless-er. It's just plain easier for me. It's not too bad to flatten a hollow grind, even if you make it on an 8" wheel (although it's a little nicer on a 14).
Click to expand...

I hear ya, but, I'm learning to flat grind because it's the hardest for me to do. I want to develop into a Maker that can do it all.
Yeah, it makes more sense to grind edge up....easier to see what you're doing.
Thanks,
Mitch
 
Thanks, guys. Too much "thinkin' and figurin"' going on lately. I'm just going to have to get in front of the grinder and do it.
Thanks again for all your help...time to hit the rack.
- Mitch
 
I agree with you Troop, it's a good skill to have. Ever since I learned how to hollow grind, I've hated doing flat grinds. Anyways, a lot of folks use the wheel to remove the bulk of steel before they flat grind, it's easier to grind on a platen if you don't have all that steel to grind off.

That being said, nothing wrong with learning it "the right way".
 
Brett Bennett said:
ib and all,

My apologies. The intersection of the planes forms a straight line and not a curve as I posted in error earlier. I guess I was stuck on the idea. Thanks for keeping me straight, ib.

Brett
Click to expand...

Ah, I just get a little wrapped up about geometry as it was one of the subjects I loved, as apposed to English, spelling and poetry. I think that some of the bowies people make come extremely close to true flat. The ones with the long sloping edge with the slightest of curves should be. Besides I used to run a fabrication shop and have been asked to make mega tonnes of metal stuff. Some of it impossible, but, for heat, clamps, wedges and big hammers.:D
 
Troop, The only other place I've lived other than Texas was New Jersey. I did my college internship at the SandBarrens Golf Course just south of Atlantic City in Swainton. Hope you get it figured out. Looks like your gettin it down.
 
Ryan Minchew said:
Troop, The only other place I've lived other than Texas was New Jersey. I did my college internship at the SandBarrens Golf Course just south of Atlantic City in Swainton. Hope you get it figured out. Looks like your gettin it down.
Click to expand...

:thumbup:Yeah, Ryan....it looks like it's coming along. What seems to be working for me, right now, is keeping the belly as "flat" as I can (to match the "flat" of the straight part of the blade), while I rotate the butt end. If I try and "lift" the butt end away from the grinder (although I'm probably doing that a little bit, too, the other way), I come to all kinds of trouble. The belly then ends up with about four different planes on it.:thumbdn:
Thanks,
Mitch
 
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