Need Help! Clean grind lines

[Burchtree]

I've made some shoddy knives off and on since I was a kid. I'd like to get better at it. I grind the bevels using a 1-inch belt grinder. The only problem is that it's extremely hard to make a straight line with this. Is there some kind of product that I can purchase that is a guide to set your blade onto to ensure even grind lines?

Thanks in advance for any help you can offer.

 

[Danbo]

Not trying to be a smartass, but I'd say get a better grinder. Seriously, the belt tracking is almost nonexistant on the 1" grinders. I went through the 1" belt machine faze, and ended up selling a couple nice custom bowies and buying a Bader BIII with the long flat grinding platen attachment. Now, I have no excuses.

I just noticed where you live. Springfield, MO is a great place to live! You have a Grizzly equipment store right there in your town. Even though most of their stuff is China made, they still make a decent 2x72 grinder for a lot less than a Bader, and it's not too much more than a 1" grinder. Just a thought.

 

[Burchtree]

Thanks -- Mine is pretty craptacular. I actually live about a 1/4 mile from the Grizzly showroom. I've been there a couple of times.

I just checked out that Bader B3 -- it's one mean piece of equipment.

From what I'm guessing, the platen is a flat piece of steel behind the belt? Mine has a small platen, but it's still impossible to not get wavy lines in my gind lines. Do you guys get perfectly even lines just by skill, or do you use some sort of guide?

Sorry for being so inquisitive, but I want to make sure and finish my knife right. I've got a tanto almost done, but I've stuck to a lot of filework to ensure even lines. I'm afraid to touch it to my grinder in case of a slip-up.

 

[Laredo7mm]

I have a burr king model 760 and had an 8 inch contact wheel put on it. I only do hollow grining because the platen on my burr king (got it for free) is not that good, plus I like the looks of the hollow grind.

There are some grinding jigs out there and I don't realy understand how they work, especially with a double edged knife But I think some makers use them, almost all of the makers that I have talked to, myself included, grind free hand.

I would suggest you goto your local scrap yard and buy a bunch of flat stack and just practice, practice, practice, and more practice. I bougt 100 pounds of flat stock when I first started grinding. You can usually pick it up for around $0.20 per pound. I probablu have 2/3 of it left, but it is a cheap way to practice. Also check out eBay for a good source for cheap geinding belts.

I don't know which grind is harder to do, flat or hollow? They are both difficult if you havenot done one. After you practice for a while you will get the "feel" I can actually feel the hollow when I grind and can make the needed adjustments to get the bevel straight....well almost straight

I still need to practice, and they get better on every knife I do. The other thing I recently got was a VFD (frequency driver) that allows me to have variable speed control over my grinder. Without the vfd my 760 was spinning at 6000 sfpm. Now I run her at about 2000 sfpm on the rough grind (40 grit) and around 1000 - 1200 sfpm on the final grind (240 grit). Check oout eBay for vfd's I got a cutler hammer for $76. Slowing down the grinder made a huge difference for me.

Hope this helps.

 

[Burchtree]

That's a beautiful knife. For some reason, I knew your answers were going to be "practice."

I think I'll stop by Grizzly tonight after I get off work and check out some grinders. I've been thinking of getting a new one anyway. The one I use now is the same one I've used as a kid. The on/off switch doesn't work and it gives me a litte "shock" every once in a while. Makes me kinda grind-shy.

 

[Darren Ellis]

Here's another suggestion for grinding practice that was passed along to me by my knifemaking mentor. Go to Home Depot and buy some 1 1/2" x 1/4 " lattice (lathe) and practice your grinding with that. It saves on belts and if you can control your grinds while making a blade out of the soft wood when you go back to steel you will really have good control as it's the same thing just much much slower grinding. May sound odd, grinding wood knives, but this really works!

In reference to the Grizzly grinder, I have one and love it. It does have its limitations though and I plan to upgrade to a KMG1 sometime next year, but the Grizzly has given me the opportunity to get into knifemaking with a low entry fee. If you do get one, have Rob Frink make you a 4" slow down wheel for it. This will reduce the belt surface speed by about half compared to the stock contact wheel and will give you more control over your flat grinds. I think he sells them for about $40...worth every penny!

Also, if you do get the Grizzly, also get a Pyroceram platen liner from Steve Pryor. This also makes a big difference.

Finally, forget the grinding jigs, unless you are trying to do production work and need to crack out many knives fast. Learn to do it by free hand.

Hope some of this helps!

-Darren

 

[itrade]

Burchtree,

Just an idea, but you might want to switch to hand sanding. It doesn't take as long as you think!

Glue a 1" or 2" x 10" piece of glass to a piece of pine (I bought a $1 8x10 picture frame and used the glass from there). Then buy 3M 2x72 ceramic and/or trizac belts - 120 grit, 220, 320. Then cut up the belt to fit 2x11" Anchor the wood in a vice and move the blade like you are sharpening.

You'd be amazed how fast those belts will cut when you are hand sanding. By moving the blade into the grind line (in other words the grind line is the trailing part of the motion), you'll get a very crisp line in no time at all. Work the bevel, then the flat. Then move up a grit.

I'm not kidding on speed. 120 grit on plate glass, cuts very fast.

Sure it takes a bit longer than a belt grinder, but you don't have to buy one and the results are outstanding.

Steve

http://www.bladeforums.com/forums/showthread.php?s=&threadid=225544&highlight=glass+grind

 

[Mike Hull]

Before you get the Grizzly, check the Coote 2X72" grinder. Head and shoulders above the Grizzly, for only a little bit more. The motor on the Grizzly is also the contact wheel mount, and drive. Not well thought out. The motor gets in the way when trying to hollow grind. The Coote has the motor mounted correctly, away from the wheels.
And practice is really the best way to become proficient at blade grinding. A jig/crutch will just make it all that much longer till you do. Plus you can better use your $$ for better tools, and steel.
http://www.cootebeltgrinder.com/
Welcome to knifemaking.

 

[tmickley]

There are several things to getting clean lines. The first and most important is practice. Everything else is a distant second.
Second there is some technique involved. Lock your arms to your sides and sway or swivel when making your 'swipes'. A few of us are fortunate enough to have a built in organic arm stabilizer. If you don't have one, eat more desserts and avoid light beer.

A 1" belt isn't as stable on the wheel or platen so you are going to have a much harder time right off. It can be done, it'll just be harder. A 2" belt will smooth out more ripples in the grind line by virture of it being 100% wider than the 1".
Generally, the closer you are to finishing grits, the slower you want your belt to move. That's the rub with the Grizzly. It really moves. Get Rob Frinks slow down wheel if you go with the grizzly and are doing flat grinds. I have a grizzly and my grinds got *much* better when I got a KMG1 with a variable speed motor. An errant twitch at a slower speed is easier to fix than one at full blast. Given the design of the grizzly, I don't think you will be able to do hollow grinds with the 4" slow down wheel. Even the 8" stock wheel with the grizz is tough since the motor housing gets in the way. I ended up using the 10" wheel for hollow grinds but the belt moved 25% faster too.
Finally, many find hollow grinds are easier to learn first since you have a groove to follow.
From cheapest to high end reccomendations: a grizzly, a coote or whole hog with a KMG1 and variable speed motor.
Good luck, keep us posted on how it goes.

 

[Saint Mark]

I have the griz and you almost have to have the 10 inch wheel to clear the motor - other than that its great!! I don't think you would be able to use the slow down wheel from Rob though.

 

[Burchtree]

Thanks everyone for your help. I checked out Grizzly last night (if you've never been to the showroom, it's a tool man's paradise.) The one for $285 seems like the one I need, they don't have any others with 2-inch belts. The only problem with it is that it doesn't seem to have a wide base -- I like having something to slide my hands across so it's not too much "freehand." The Tanto I'm making is coming along nicely (nothing near the quality you guys are probably making), it's just taking a lot of filework, grinding, and hand-sanding.

Once again, thanks for all the input. I appreciate the help. I might take a picture of my current belt sander so you all can get a good laugh.