Bevel grinding help

As a new knife maker I have lots to learn. I have started on my fourth knife and one thing I have noticed is that I have a really hard time keeping a straight grind line when I am grinding from right to left. If I grind from left to right I can keep a pretty neat grind line that is easily cleaned up as I change to higher grit belts. When grinding right to left my grinds can be all over the place. It seems with every other pass my lines change, the geometry changes, etc... I have yet to use a jig as I really don’t want to depend on one. I’ve tried setting the piece on my tool rest and sliding it across the belt so my grind line stays straight but then my geometry gets messed up with each pass or if I totally freehand it, my geometry stays consistent but my grind line is really wavy. Any suggestions on what I can do to be more consistent no matter the direction I’m grinding?
 

BossDog

KnifeDogs.com & USAknifemaker.com Owner
Staff member
Good news for you. If you can get one side good, the other side will come in time.

This is really typical. Your strong hand always grinds better than your weak hand.

Some suggestions.
This will be hard but start every grind with your weak hand and then match it with the other.
Don't grind one side completely and than the other. Grind your weak side a bit, then match it. Repeat.
Watch exactly how your strong side moves the blade across the belt. Copy that move on the weak side.
Expect to spend 50% more time on the weak side. Go slower on the weak side.
There are no special tricks. Everyone had or has this issue. It's simply a matter of practice.

When you get 20 or 30 blades under your belt, you will find it's much easier. A craft that you can master in a few hours is probably not a real craft.
 

EdCaffreyMS

"The Montana Bladesmith"
Here's a hint..... DO NOT try to start your plunge cuts, where you want them to end up. Start forward of where you want them to end up, and then "walk" them back, and into alignment right at the very end of FINISH grinding.

You can always take material off if needed.....but if you're already too far back.....nothing you can do, because you can never add any after it's ground! :)
 
mister Caffrey im going to attempt my first chopper from a 1 3/4 farrier rasp i want to flat grind to spine should i start with a flat grind ore

( Start forward of where you want them to end up, and then "walk" them back, and into alignment right at the very end of FINISH grinding. ) walk the flat up ?
 

EdCaffreyMS

"The Montana Bladesmith"
While mil steel can be helpful, it has the drawbacks that is does not grind the same as carbon/alloy/stainless steel, especially in the heat treated state.

That being said, grinding "practice" is always a good thing in that the more you do it, the more it becomes muscle memory....which is exactly what is required.
 

Sean Jones

Well-Known Member
You might consider getting a Bubble Jig. I use it a lot. And while it is a jig, it gives you a lot of freedom and develops the muscle memory for free hand grinding. It suits me well because sometimes I'm not in the shop every day and your muscles 'forget' rather quickly. At least they do for me
 

Chris Railey

KNIFE MAKER
You might consider getting a Bubble Jig. I use it a lot. And while it is a jig, it gives you a lot of freedom and develops the muscle memory for free hand grinding. It suits me well because sometimes I'm not in the shop every day and your muscles 'forget' rather quickly. At least they do for me
I have thought about whether or not the "Bubble Jig" qualifies as a jig other than the fact Fred named it a "jig". As genius as the thing is, you can mess a blade up just as quick as "all freehand" work. I will say for those other grinders out there with ADD it is a life (*blade) saver.
 

Sean Jones

Well-Known Member
I have thought about whether or not the "Bubble Jig" qualifies as a jig other than the fact Fred named it a "jig". As genius as the thing is, you can mess a blade up just as quick as "all freehand" work. I will say for those other grinders out there with ADD it is a life (*blade) saver.
You certainly still need to pay close attention. And for some, including me, it's a balancing act between keeping the bubble centered and watching the grind. I'm still not comfortable starting an initial grind without it. Though later on during cleanup I'll set it aside and 'freehand'. Though by that time the initial grind is usually established the way I want it.
 

tkroenlein

Well-Known Member
Most of the issues I've had with wandering grind lines were/are caused by pushing or pulling the tang toward or away from the platen as I bring the last third of the blade across the platen. Does that make sense?

It's a lot like swinging a shotgun. Focus on what happens until the whole movement is over. Follow through.
 

Chris Railey

KNIFE MAKER
Yep, I solved that one by locking my arms and shoulders in place and simply shift my weight from one foot to the next to move the knife across the platen. Almost like my hands and arms were a jig that cannot move and stayed at the same angle while my body moves the jig. Yeah, that more than likely does not make sense to most but it does to me.
 

John Wilson

Well-Known Member
Yep, I solved that one by locking my arms and shoulders in place and simply shift my weight from one foot to the next to move the knife across the platen. Almost like my hands and arms were a jig that cannot move and stayed at the same angle while my body moves the jig. Yeah, that more than likely does not make sense to most but it does to me.
Makes perfect sense. I want my upper body/arms locked in place and I slide side to side like my butt is sitting on a track. After a while I learned to hold this position without being tense. It's actually relaxing now. But my body is the jig.
 

John Wilson

Well-Known Member
The big "lightbulb moment" came to me when I realized that the key to grinding flat bevels is to first establish a "flat". Once you establish a nice flat area it's so much easier to lay the blade on the belt the same every time. As simple as that sounds, before I came to this realization it seemed like every single pass was hoping for the best and the next pass was a slight correction to the one before it. I was forever chasing my grind line.
 

Sean Jones

Well-Known Member
Yep, I solved that one by locking my arms and shoulders in place and simply shift my weight from one foot to the next to move the knife across the platen. Almost like my hands and arms were a jig that cannot move and stayed at the same angle while my body moves the jig. Yeah, that more than likely does not make sense to most but it does to me.
That's exactly what I do.
 
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