Work Rest / Gringing Jig

[Brian Avila]

Weatherman, you piqued my curiosity, so I went out and put a magnetic protractor on the thing. It looks like I will be able to get a 2.5 degree angle on the flat platen without lowering the cutout and only removing material about half way down the back of the plate. That should allow the same plate to work for me on a platen or wheel, which would be good. I probably have an hour or two of grinding the back of the plate to sure, but it looks good so far.

EA

This is awesome.

Do you think you could send me the how to, on the materials, sizes, etc and how you made this? Because this is something that I would like to make.

 

[ERIK KNIVES]

I made a few adjustments today - added a Micarta plate near the hand wheel to make the action more rigid and put in a bigger guide pin in on one side (and then ground off a few thou), because I missed the drill mark by just under a 1/16" and there was a touch of slop. It's hard to be precise with canvas Micarta and my equipment. I have a few more things I want to do to it before I grind on it, so we'll have to wait and see how it performs. Setlab, I would have no problem posting video, but I like sharing thoughts with this community, not necessarily the world. Any ideas? Knife and Brett, I'm trying to make an easy way to set primary flat and hollow bevels, speed up my initial grind on my secondary bevels, and yes, add a swedge at times. Bob, nothing ground on it yet, still in development. It is a big lever, the 3/4" rod is the weak point - I can flex it if I get on it, but I believe it will be fine for grinding. That 1 1/2" square rod doesn't move at all. I did add two opposing knob/screws to my receiver (three total now) so I can true the whole thing up to the wheel or platen - the whole assembly is really heavy. Weatherman, I can tell you the materials and dimensions, and to a degree how I made it, but I' still making it and I use my skill set and tools which is different than yours or others. My grinder is different as well. Let me test it first, if you are interested after that, shoot me a PM or email and we can talk on the phone. I posted here for inspiration to BF members (and visitors) to think about options in their shop. Who knows, this thing may do one thing well, I hope it does 6 things well. It may be a paperweight. I have just enough experience to be confident it will not be a paper weight, but it's not tested yet. Here's an updated pic with the bottom plate/guide and a pic of the larger guide pin.

 

[Brian Avila]

I think it is great, I will shoot you a PM soon. I can see it addresses some of the problems that I have come to in my adjustable table and angles already. It does inspire me!!!! Thank you sir!

Brian

 

[jonnymac44]

Erik my friend......you are one badass mad scientist!! I'm loving watching this thing come together:thumbup:

I'm pretty happy with this sucker, but have a few tweaks left and then will grind. Again, I post this stuff to get people thinking about ideas and what they may want to try. Thanks to David Sharp for the inspiration, although, he would never use this .

 

[ERIK KNIVES]

Thanks, Jon. A buddy of mine before I knew him in person gave me a Rube Goldberg reference. I hope I'm getting better, lol.

EA

 

[David Sharp]

Clean it up and put it on a shelf! Pure mechanical art.

Do you intend to make rotational adjustments at both the 1.5" tooling arm and the double clamp?

 

[David Sharp]

Clean it up and put it on a shelf! Pure mechanical art.

Do you intend to make rotational adjustments at both the 1.5" tooling arm and the double clamp?

 

[ERIK KNIVES]

Clean it up and put it on a shelf! Pure mechanical art.

Do you intend to make rotational adjustments at both the 1.5" tooling arm and the double clamp?

Thank you, David. From you, that compliment means the world to me. I think the adjustments you are talking about may exceed my skill-set and/or workshop :|
I did make a few adjustments today, however. I wanted near perfect tracking and better horizontal rigidity of the Micarta rest. I swapped out the stainless drive screw for a hardened one, added 1 1/2" stainless screws to the guide tabs for strength, added a collar on the bottom of the screw (so the screw would not walk away from the rest on downward motion), and added an adjustment screw on the left side to remove any side-to side slop. 100% improvement on the tracking, rest is super solid on far ends, and the wheel action smoothed out nicely. I was trying to explain to some girls who were in my garage today what it did (they didn't get the concept), so I flat ground a paint stick for them which was my first real test of the thing. So far, so good. Here's a 4 in one image to show today's mods. I hope to see you soon. EA

 

[Patrice Lemée]

Clean it up and put it on a shelf! Pure mechanical art.

Exactly!

 

[NickWheeler]

Super cool Erik!!!

My gut reaction is that I would use it more without the fancy lift thing-a-ma-jig. Can you explain to me (I'm a bit slow....) how you will use the lift/height adjustment in use?

Very nice giz-wizz Erik! :thumbup:

 

[ERIK KNIVES]

Thanks, Pat, Nick. Nick, I plan to set the angle to what I'm looking for and raise the micarta rest until the blade is just touching the belt. Run a few passes, and then turn the wheel to raise the rest a bit, and then more passes until I'm at the grind height I want on the blade. For a full height flat grind, I anticipate taking the jig off after I'm a little past the half way mark on the blade and have more surface area on the bevel than the flats, and grind it free hand or with a basic flat workrest for support. I believe on hollow grinds, I will be able to run the bevel as high as I want with this alone. For swedges, I may try adding a removable piece to the top of the Micarta that has a rounded top, so I can rock the blade to follow the shape of the spine, or just drop the rest all the way down and out of the way. It's all very experimental, but I'll let you know what it does or doesn't do well.

Take care, Erik

 

[ERIK KNIVES]

I researched a bit and decided that I needed to get close to a one degree angle for what I want to accomplish. I started out with this project hoping for a 5 degree angle, found out I could easily get 2.5 degrees. After seeing the math (thank you, Steven Penner), I went to town on my rig. I want to be able to reach a 2" inch bevel height (flat grind) with a close to .100" spine or stock, and a way to get there. 1.3 degrees appears to be my target. Thankfully, my buddy made me a 10" platen (A2), and that is what I needed for this set-up. I have been told that none of this matters, but the point of a jig is to provide accuracy, so I have to disagree. I've seen sleds and bubble jigs and other tools. Get rid of your drill press if you think knife making has to be done eyes and hands alone, trade in your belt grinder, too. Almost every knife I make, I have to hand work on a granite slab (thank you, Stacy for the tip), but I will not apologize for trying to make my work faster and more accurate, especially when I build the tools to make the tools I want to make.

Here is the steel I cut on a belt, working towards to 1.3 degrees.

Here is the present result.

Here are some progression photos, and some calcs. The funny thing is, I learned by doing this, how to accomplish the same objective without the hours of grinding the plate. Someone smarter than me will most likely see it too. I'm not talking about free handing, I'm talking about how to accomplish the same tool with less work.

Grinding and cooling the plate.

The reason a low voltage footswich is a good idea.

How fast water creates rust when the steel gets hot.

Hours of this....

What I'm working toward.

 

[Jkite]

So how's it going? Any progress? I'm digging the rest. I guess in stead of grinding the plate you could have used two pieces of angle.

 

[ERIK KNIVES]

I did have some progress, I finished it. If and when I make another, I won't use angle I will modify something else to save grinding the plate. The hardest part turned out to be truing the plate, it had a touch of warp. I should have used some precision plate or had it surface grounded to precision, but I was buying scrap cold rolled, and hind sight is.....hindsight. Grinding the back may have warped it a bit, but I don't think so because I kept it "hand-cool." Cleanly bending 1/4" plate to true is not easy, I employed the bastard file and disk where necessary. I had to move on to another project, so I haven't ground any real steel with it yet, but I will come back and tell you how it goes.

EA

 

[tryppyr]

Beautiful stuff. I love the design. You should patent it.

 

[Brett Mathews]

Eric, Im sure your warping was do to the removal of metal regardless if it got hot. This has happened to me a few time with plate. I once had a 6x6x.5 piece and made a cut 3" long cut down the middle with the band saw and it sprang .625" in that 3" cut. If you still need it trued up I can shim it up then the surface grinder true if you would like.

Brett

 

[ERIK KNIVES]

Hey Brett, thanks for sharing your experience. That is also a very kind offer - thank you. I believe I have it true enough now that any improvement would not make a noticeable difference. Thank you again.

EA