Grinding Jig Opinion

B

buckaroo2219

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Feb 13, 2013
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Just wondering what your opinion is on using a jig to grind bevels. I have seen posts both pro and con. Does it take away from the skill or add repeatability.
 
For me I made a couple with a jig then I moved to freehand and draw filing, i prefer freehand as I find it to be faster (for me) and I tend to clean my file much much more, I also feel that it reduces my risk of making an Uh-Oh when doing it freehand. Thats me 2 cents, but nothing wrong with a jig imho. These other guys can chime in with much more experience than I can though
 
Learn the skill of grinding freehand until you are comfortable with that. Then, if you feel it helps you speed up production later you can add the use of jigs to your skill set.
 
Not meant to be a plug for the jigs I sell but a comment.

When I started offering them I thought it would be mostly beginners that would find them usefull.
To my surprise there are as many full time knife makers ordering them.
I think its the repeatability and speed where they come in usefull. If you keep some simple records of what you had it set on. Ten years later you could come back and make the same grind.
Sometimes I'll do my pre HT grind using the jig then grind freehand post HT.
 
Jim, I am curious about the grinding post HT. I personally don't do that. Than again, I don't know much. Still a rookie at this. From what I read is that grinding post HT can damage the HT. Could you explain that to me please? I see this a lot on posts where people talk about post HT grinding. But what are they exactly grinding? Shouldn't the bevels be completely finished before the HT? Inquiring minds what to know! :)


Jim McGuinn said:
Not meant to be a plug for the jigs I sell but a comment.

When I started offering them I thought it would be mostly beginners that would find them usefull.
To my surprise there are as many full time knife makers ordering them.
I think its the repeatability and speed where they come in usefull. If you keep some simple records of what you had it set on. Ten years later you could come back and make the same grind.
Sometimes I'll do my pre HT grind using the jig then grind freehand post HT.
Click to expand...
 
shurik6 said:
Jim, I am curious about the grinding post HT. I personally don't do that. Than again, I don't know much. Still a rookie at this. From what I read is that grinding post HT can damage the HT. Could you explain that to me please? I see this a lot on posts where people talk about post HT grinding. But what are they exactly grinding? Shouldn't the bevels be completely finished before the HT? Inquiring minds what to know! :)
Click to expand...

Don't worry guys, let an expert handle this one ;)

Every stock removal knife maker I know of does quite a bit of grinding after HT. This is necessary because most only grind to about 400 grit before HT and becuase you have to leave a pretty significant amount of material at the edge to avoid warping in the quench. Many blades are ground up to above 800 or 1000 grit so, although there's not a lot of real shaping going on at this point, there is significant smoothing and polishing.

The trick with grinding after HT and temper is that one has to avoid over heating the the blade and ruining your temper. I do all grinding post HT with bare hands to closely monitor temperature and quench every few passes.

And from my very limited experience, Jim's Angle Pro jig has been a life saver. I guess some of these makers are just so badass that they can free hand some amazing grinds but I would venture to say the majority of us aren't there. I tried it and thought I had a great grind until I got above 600 grit and realized I was holding a cratered shard. Everything looks great at 220 grit! I ended up having to completely re-do my grind post HT- massive waste of time.

For those that don't want to burn through a bunch of steel learning to free hand a perfect grind or spend massive time fixing gnarly grinds, I would definitely suggest a jig.
 
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Turbodog has it right.
Some knife makers do all grinding post HT.
Just keep it cool if you get the blade hot enough to change color you have got it too hot.
You should stop grinding when you get the edge down to between 30 to 40 thousandths.
 
Woah, that thing is like a Christmas tree! And here I thought that it will be some embellished angle iron. lol I'll just stick to my HF 1x30 and a piece of angle iron to keep things simple for now. It's like a rite of passage for knife makers, it seems. When I will stop spending most of my money on baby diapers, I maybe able to afford something decent like this. Thank you for your input.
 
Having a woodworking background I am a firm believer in jigs and when I started I used a jig, but after reading on here several times people recommending to try it without jigs I gave it a try freehand. I am so glad I tried it freehand , it was the best thing I have done so far for my knife making.
It was easier for me (well lets say I didnt throw away as many) to get the feel for grinding when I used steel that has already been HT'd, just dunk in water to keep cool after each pass. At least give freehand a try.
 
Find out what works for you, and go with that. For many it takes 40 - 50 knives at least to find their way. Frank
 
Interesting responses. I make my living in woodworking. Jigs are a big part in repeatability. I have done blades with and without jigs. For me I prefer the jig. I get faster and better grinds.
 
turbodog10 said:
Don't worry guys, let an expert handle this one ;)

Every stock removal knife maker I know of does quite a bit of grinding after HT. This is necessary because most only grind to about 400 grit before HT and becuase you have to leave a pretty significant amount of material at the edge to avoid warping in the quench. Many blades are ground up to above 800 or 1000 grit so, although there's not a lot of real shaping going on at this point, there is significant smoothing and polishing.

The trick with grinding after HT and temper is that one has to avoid over heating the the blade and ruining your temper. I do all grinding post HT with bare hands to closely monitor temperature and quench every few passes.

And from my very limited experience, Jim's Angle Pro jig has been a life saver. I guess some of these makers are just so badass that they can free hand some amazing grinds but I would venture to say the majority of us aren't there. I tried it and thought I had a great grind until I got above 600 grit and realized I was holding a cratered shard. Everything looks great at 220 grit! I ended up having to completely re-do my grind post HT- massive waste of time.

For those that don't want to burn through a bunch of steel learning to free hand a perfect grind or spend massive time fixing gnarly grinds, I would definitely suggest a jig.
Click to expand...

I do stock removal. I grind to 120 before heat treat and I grind to about .02" thick at the edge, then heat treat, and then take the edge down to just below .01". I think it is more important to have even grinds and symmetry to help with warp issues than it is to just leave a lot of material to account for warp. I know guys who do ALL their grinding after heat treat as well, I have done it and prefer grinding before heat treat and then finish up after heat treat.

There is nothing wrong with using jigs. You make knives and do it the way you can. Having said that, I think it is important to learn all the aspects of the grinding, which includes free hand as well. It will give you skills that will contribute to expanding what you can make compared to only using jigs. Not only that but what are you going to do when you go to someone else's shop and they don't have any jigs that you have in your shop? But I have to agree that I prefer grinding clips on a angled table compared to doing it free hand ( takes the weird muscle twitch "oops" out of the equation ).
 
Hey guys, chiming in.

I have been a wood worker and maker of things my whole life, scale model aircraft, boats, scale trucks... etc. While i find free hand to be the best base of all fine work, i have never been able to reproduce the preciseness i can get from using a jig. A jig is the best way to reproduce the same thing over and over. and from my experience in wood working a piece of plywood with a hole drilled in it set to an edge is the best way to make sure you put the whole in the same place everytime. the same goes for filing metal, wood, anything really. I made my first couple knives completely free hand. I wanted to build up that muscle memory of using the file, using the same pressure, and keeping a good angle. then i saw the jigs that some guys were using and made my own. using the same muscle memory and a jig has created some of the best grinds to date so far. i am not saying that using a jig produces better lines than freehand. i am saying that it is an obvious choice when trying to reproduce similar grinds over and over.

i think there is just as much time for a oops with or without a jig really. I don't have a grinder or anything and make my knives with jigs only at this point. but i find with a jig that i can get the knife/bevels done faster than i could before. and with much less need to draw file to get that perfect flat grind.
 
Man I completely misread the OP title, I thought he was asking about a file jig, damn bourbon! I don't see an issue using a jig for grinding. I'm waiting for one of Jims jigs to work with a craftsman 2x42 until then I am just free handing
 
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