Bevel Jigs

Status
Not open for further replies.
J

John Hoe Handle

Joined
May 3, 2017
Messages
22
Does anyone have experience with bevel jigs? Which one do you recommend?

I do it by hand now. Sometimes good, sometimes bad. This weekend, my camper knife, I was chasing a bevel and ended up getting a full flat grind to the spine. Seems I do good when the knife is in my right hand, but always trouble with the left hand.

I know it takes practice, and the guy who taught me suggests keep doing it by hand. But chasing these facets gets frustrating.
 
Personally I'd stay with free hand grinding. I tried jigs when I first started, and I'm very glad I stopped quickly and learned freehand. Once you get the hang of it I'd be willing to bet freehand is faster (I quite literally lean all of my weight into the grinder) and much more versatile in regards to blade shape

One suggestion I could make is to grind the bevel with your left hand first, and do your strong side second. It's often easier to match them up that way.

Sharp belts help too. I usually toss them as soon as they start slowing down. I can be grinding with a dull belt and making a total mess of it. Put a fresh belt on and within one or two passes the grind is perfect.

On the ABS channel on YouTube there is one video of Jerry Fisk talking about profiling, and he explains the exact grinding approach I've always found to work best.
 
I have 2 homemade 'jigs' and can not say anything but keep trying. If you have variable speed, slow down and use lighter pressure. I just fixed a blade which is my first hollow ground that I started with a jig and had to fix by freehand. If you don't have variable speed use very light pressure when putting the blade to the belt and be very cautious of the angle.

I can completely identify with being good right handed and then jacking everything up when I switch to my left. I also found that it's better to try and chase it with a slightly higher grit. Chasing it for me with a course grit and I'm chunking messed up blades. Just tonight I got it close with the 36 switched to 80 then 120 and finally got it to where I want with 220. I have to take it slower as it's already heat treated and it's taking longer to fix, but I have just a few more spots to even out and it'll be a good knife. Best advice I can offer is don't chase it far with a course grit.
 
One thing you might do is try is resting the knife's spine on the tool rest. Then just pull it across the belt. That's how I free hand grind.
 
I've tried several paid for jigs and don't like them much. I recently started forging and it's amazing how much easier it is to grind once you've established the bevel. I know that's not a good answer, but if you had designs to forge (apologies if you do already) then hang in there...it becomes more enjoyable imo.
 
sounds like you are already have some feel for freehand grinding. i think you should get a fred rowe bubble jig. it will eventually teach you to hold the knife at a consistent angle and you wont need it anymore. i had the same problem with facets, my blades looked those indian arrowheads that were flint knapped out of stone they had so many facets :D. and the bubble jig is inexpensive. you will see results on the first try. there are youtube demos of it.
 
I can second the Bubble Jig. I just got one this weekend and it has already helped. Instead of chasing a clean grind line up toward the spine, I get one much earlier on. It's a good way to get feedback on proper orientation quickly.
 
I think that's a little confusing, as it's not actually 'free-hand'. I think I see your point, as you're not using a jig, but the work rest is what's supporting the workpiece, and not your hands. 'Free-hand' means without any support other than your hands. ;)

I'm not implying that there's anything wrong with any of these methods - it's important to do what works for you!

To the original poster, make sure you're using fresh, sharp belts. The faceting you're experiencing can come from the sloppiness that occurs when you're not cutting efficiently.

JG Custom Metal Works said:
One thing you might do is try is resting the knife's spine on the tool rest. Then just pull it across the belt. That's how I free hand grind.
Click to expand...
 
Bubble jig. It's the only jig that is more of a teaching tool rather than a crutch.
You can visibly see the slight difference in position when you switch hands so you are able to correct your "form".
 
Matthew Gregory said:
I think that's a little confusing, as it's not actually 'free-hand'. I think I see your point, as you're not using a jig, but the work rest is what's supporting the workpiece, and not your hands. 'Free-hand' means without any support other than your hands. ;)
Click to expand...

Tomato tomaato. I say using 2x72 grinders is cheating. If you aren't forging to 90% and then finishing with files, then you're no bladesmith. ;)
 
I fourth the bubble jig. Like said above, you use it to make sure you are at the same angle and can build muscle memory and then eventually stop using it.
 
I still use one to some degree. Mostly for swedges because they're so short. The other night I ground out a little 6" bowie from 3/16 completely freehand because I put a fair bit of distal taper into it before grinding the bevels. It went surprisingly easy. My progression in learning to grind freehand has been something like this:

1. Try to grind freehand flat bevels, lots of failure
2. Using a jig to grind the bevels. Still some failures, mostly at the tips and plunges.
3. Using the bubble jig start to finish
4. Using a jig to simply get the bevels started, then following them freehand. This taught me more about getting even with both hands than anything, as well as how pressure towards the edge/spine effects the height of the grind.
5. Using the workrest/push stick method. I did this for only 2 or 3 knives and I do not care for it in the slightest.
6. Freehanding on a wheel. Starting this it was immediately apparent how much easier it is to follow the wheel than it is to follow a flat platen. It may not be perfectly accurate to say this, but it seems to fit, grinding on a wheel is like having 3 points of contact between the knife and the grinder versus only having 2 points of contact on the platen. So this helped develop some more muscle memory, and I freehand hollow ground 20-30 knives before trying a platen again.
7. Finally developing the freehand method I'm comfortable with. Scribe center lines, and note, I stay in front of where I want my plunges to actually be until the last step, grind a 45 degree chamfer on both sides, walk the grind up halfway on one side and then the other, walk it up 3/4 on both sides, and when I'm getting towards that 3/4 point I'm being more careful about how the two bevels meet the edge, are my initial 45s gone? At 3/4 height I'm evening the edge out mostly and getting toward that pre-heat treat edge thickness whatever it may be. The last step is bringing that 3/4 height to the desired height. I flip back and forth a lot. As I near that final grind height, I begin bumping the plunges back to where I want them. Waiting until the end has helped me considerably in getting them both evenly centered (viewed from the edge) and symmetrical in appearance (in regard to radii). After heat treat, it's a simple matter of just following what you've already established.

My jig is just a piece of angle iron with plastic on the bottom and tapped holes in the face. I don't regret using it in my learning progression and think they can teach you things you might not learn without using them, by constraining your knife in one axis repeatably, it significantly helped me visualize what a grinding pass could do, and what I would have to do freehand to change it rather than just mimicking what the jig did.

Last bits of advice, as has been said, dull belts will cause you all kinds of problems that you assign grinding ability as the cause, when in reality it was more about you fighting the belts performance than a simple lack of ability. Having your platen true and square and flat in all axis is important. Given the construction of most grinders I would hazard to say that almost none of them that rely on fabricated shapes to hold things in the same plane are sufficiently square without some shimming, just due to material tolerance for flatness and straightness. And if you're using a ceramic glass platen, knock the edges off a bit so they're not sharp. You don't need a 1/8 radius on them, but a little edge break was a significant improvement for me when trying to get plunges even. Learn how to fix grinding mistakes. In your OP example, you ran a bevel up to the spine and you didn't want to. So what? Grind the flats back down to where you want them. Make sure your steel is straight. There's nothing worse than getting tunnel vision about grinding bevels evenly with a centered edge and chasing your tail only to find out you've been grinding a banana shape, and after heat treat and straightening, all that tail chasing was for naught because nothing is even anymore.

I'm just coming up on a year since I built my first grinder and started doing this with purpose. I wish I'd kept track of exactly how many, but I believe I've rough ground around 150 blades in that time. I haven't finished that many knives, and I've thrown some away. I've bought hundreds of belts, far more money in belts than blade steel, and only now am I starting to feel competent enough with grinding to finish knives on the grinder rather than hand sanding. So no matter what you do, it's going to take more practice than you might think.
 
Wheels are definitely much easier and faster to grind on, in addition to making your belts last longer. My flat grinds start on a 12" contact wheel. I can rough out 90% of the metal on a normal sized drop point hunter in a minute or so. Then just one or two passes on a platten will have it ready for heat treat. Maybe it's just me, but I find I can lean a contact wheel as hard as I can, but I'm never really able to apply nearly as much pressure on a platten. I've tried a push stick as well, and didn't like it.


I found the thing that did the most for my flat grinding was making a couple of 10" chef's knives. The first few were unbelievably difficult, and I spent the better part of a day fumbling around with various different belts trying to clean them up. The wide blade on thin stock will magnify every aspect of your grinding like you wouldn't believe. I had never had a two inch line before, but I could hardly grind a chef's knife without them.

After a few days of figuring it out, all of my grinding went so much smoother. Large chef's knives and roast carving knives are some of my favorite things to make now
 
I tried jigs and they distracted me. I find i have to get "in the zone" so to speak when I'm grinding to be successful. It's one of the things i really love about making knives. With the noise/ earmuffs blocking out any sounds, it's just you laser focusing on a 2" area. I do use a carbide faced file guide on most knives and it helps to get your plunges lined up. I don't always use it, and I only use it early on to set my plunges in the low grit grinding stage. I worked with my best friend recently to help him make his own knife. I realized at the last minute, that I had taken my ability to freehand grind for granted. Seeing that there was no way he was going to make a serviceable knife freehand, I screwed the blank to a piece of angle aluminum i had sitting around. I bolted on my never used work rest and he turned out an excellent first knife. I DO wish i had purchased a bubble jig at the get go. It seems like one of the few work aids that will actually facilitate you getting to freehand grinding and not having it be the thing you have to use forever to grind knives. (again, no slight on jig users, like golf- it doesn't matter how it gets there, it's the result that counts.)
 
I make blades with almost straight edges. I have several pieces of angle iron, 12-14 inches long, 1", 1.5", and 2". holes in angle iron that line up with holes in tang. mount blade so edge is parallel with tool rest. adjust belt to required angle(below 8 degrees, I have some machined pieces that are exactly 8 degrees that I can mount to the angle iron) mark blade with sharpie and grind. turn blade over and repeat. I also have a file jig that I use to start the edges.
 
Try putting on your work rest.
Then make a fist and place the knuckles on the work rest, straighten out your index finger, lay the spine of your blade on the index finger with your thumb used to apply pressure to the blade and practice pulling the spine across your finger with the thumb controling pressure.

What you have is total hand contact with the support of the work rest. This way you can control all aspects of movement and pressure of the blade as you draw it across the platen.
 
I wish I had been more consistent in my training. I started off with the bubble jig. I had pretty good success. But still, I guess I was searching for the Holy Grail of grinding (I now know it's called buying a finished blade) and tried the sled jig types.

I felt they were to limiting, so after wasting time, which I could have invested in more freehand grind time, I returned to the Bubble jig.

Which I still use to set my rough grind. After the rough grind, it's easy to follow the grind and just fine tune.

I must concur regarding learning on large chef knives. It has helped me a lot. Even with the smaller blades.

And I'd also like to thank all good people on this forum which has helped me tremendously.
 
yes, I almost forgot about larger blades. You can really feel where the flat is doing them and it has helped me know what that is supposed to feel like on smaller knifes. I noticed this especially when i did my competition chopper.
 
AVigil said:
Try putting on your work rest.
Then make a fist and place the knuckles on the work rest, straighten out your index finger, lay the spine of your blade on the index finger with your thumb used to apply pressure to the blade and practice pulling the spine across your finger with the thumb controling pressure.

What you have is total hand contact with the support of the work rest. This way you can control all aspects of movement and pressure of the blade as you draw it across the platen.
Click to expand...

I'll need to try this. My struggle freehand grinding is when the blade has any real length to it. I can do ok at short blades, but longer blades my biggest challenge is keeping the belt from pulling the tip down. It becomes this game of tip dropping, overcompensating and flipping the tip up, backing off the pressure to try to avoid the issue and mucking it up that way. Your approach sounds like it makes a lot of sense, but it's something I'd never even thought to try.
 
For matched sets of steak knives I use a rest from ddworkrest on IG. Easy and almost perfect every time. All other knives freehand with a push/support stick but no tool rest.
 
Status
Not open for further replies.
Back
Top