is the "smart jig" from KnifeJigs.com any good?

G

galaxyknives

Joined
Feb 8, 2017
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so, first of all, I'm new to this forum as well as being a pretty new knifemaker

i've been googling around the internet, and looking for a better way to grind my knives. in the past i've used the filling jig first used by gouch custom, but i'm thiking about investing in a 2x72" grinder later on, thus i want to become better at grinding bevels by hand.

i already own one of those 1x30" grinders and i was thinking that i would start practicing with it :)

here's the deal though, i found this guy on youtube (knifejigs) that sells these electric guides that you can program with your pc and all of that. i would have bought one, but i though it would be a good idea to ask you guys' opinion first

thanks in advance :D

here's the link to the website: https://www.knifejigs.com/collections/electronic-jigs/products/smartjig-model-kj2400u
 
Wow, I am kinda shocked that this is an actual product. If you need help grinding then get a bubble jig.
First thing I noticed was the exposed USB port that faces the grinder. Save your $200 and use it to buy steel and belts and practice. This thing does not help you when you get to the nose and need to sweep the grind. This is the area where most have issues anyway.
 
I think innovation in knife making tech is always a good thing. However, I don't see the virtue of the SmartJig.

99.8% of the jigs out there operate on the same basic principle (outlined here https://youtu.be/jj4ffxIPTT8). If you want to work with jigs, why not start with something that is ubiquitous and proven?

The Smart Jig and the BubbleJig are functionally the same thing - they lock onto the knife, and indicate the angle between the device and true level (we'll call this "angle A"). This is a problem, because this is not the angle you are concerned with - you are concerned with the angle between the platen and the steel (we'll call this "angle B"). As JT mentioned, when you grind the nose/belly/tip of the knife, these types of jigs don't really help because angle A and angle B are different when you're at a curved section of the blade.

If you don't agree with or understand what I mean, try drawing everything in a 3D modeling program. Or imagine that you are grinding the bevel on something extreme like a chakram. You would start with the BubbleJig or SmartJig at the 12:00 position. As you rotate the chakram, the jig sweeps from 12:00 to 3:00, and its reading becomes less and less meaningful. Eventually the BubbleJig or SmartJig will be at the 3:00 position, and here, its reading is completely meaningless.

The "normal" grinding jigs have a similar problem - as you grind the knife tip, you lose the benefit of the set angle and must 'cheat' the grind. This is hard to explain in words, but again, if you imagine grinding something extreme I think you'll get it.
 
Contrary to the name, I think it's stupid. You can advance your skill free handing a whole lot with $200 worth of steel and belts. I have nothing against jigs or guides, but I would use a bubble jig if I had trouble figuring out how to maintain an angle. That said. Once you start to feel what is going on with a flat grind and have a repeatable technique to move the blade across the platen, you are in business and the jig will sit, except perhaps if you use it to sharpen.
 
Welcome to the forums and to knife making!

As for the smart jig, I've seen it pop up once or twice before, and the reception always seems to go the same way...
If that thing was only $20, I doubt even then I'd see the usefulness of it.
If you want something just as (or arguably more so) effective, and for much less money, try Fred Rowe's bubble Jig. It's a little more "analog", but much more of a sensible design.
 
P.Brewster said:
I think innovation in knife making tech is always a good thing. However, I don't see the virtue of the SmartJig.

99.8% of the jigs out there operate on the same basic principle (outlined here https://youtu.be/jj4ffxIPTT8). If you want to work with jigs, why not start with something that is ubiquitous and proven?

The Smart Jig and the BubbleJig are functionally the same thing - they lock onto the knife, and indicate the angle between the device and true level (we'll call this "angle A"). This is a problem, because this is not the angle you are concerned with - you are concerned with the angle between the platen and the steel (we'll call this "angle B"). As JT mentioned, when you grind the nose/belly/tip of the knife, these types of jigs don't really help because angle A and angle B are different when you're at a curved section of the blade.

If you don't agree with or understand what I mean, try drawing everything in a 3D modeling program. Or imagine that you are grinding the bevel on something extreme like a chakram. You would start with the BubbleJig or SmartJig at the 12:00 position. As you rotate the chakram, the jig sweeps from 12:00 to 3:00, and its reading becomes less and less meaningful. Eventually the BubbleJig or SmartJig will be at the 3:00 position, and here, its reading is completely meaningless.

The "normal" grinding jigs have a similar problem - as you grind the knife tip, you lose the benefit of the set angle and must 'cheat' the grind. This is hard to explain in words, but again, if you imagine grinding something extreme I think you'll get it.
Click to expand...

I have ground over a thousand blades, using a Bubble Jig and I have never had the problem you are referring to. Of course not every blade is what you describe, with a belly or hard turn at the tip.
What I recommend using a BJ is to create the straight areas of the bevel first, from plunge forward. Once you have matched flat bevels, grinding anything forward, I find very easy. It's creating matching bevels that is the initial task, once you have a datum to work from, all other areas of the blade come easy. On forged blades, I set the ricasso, then grind the distal taper, [also using the Bubble jig] then the bevels, then the tang on the same plane, [using the Bubble Jig] and lastly I grind the area forward. Using a Bubble Jig the maker can grind the tip and the belly, alone with out having to touch the matched bevels. Remember, you are working with accurate, matched bevels.
In the thousand plus blades I have ground, I found after perfecting my technique, I can grind a blade faster, much more accurately and with exact repeat-ability, than I can grind free hand, which I am pretty good at.
I have never used a "Smart jig" and it may be a fine tool. The Bubble Jig has been on the market, for 8 years, selling close to 3300 hundred to makers all over the world, including the North Pole, we must be doing something right for we have only had one returned in that time.

There are many ways to grind blades and no one way is the "right" way, including "free hand"

Regards, Fred
 
thanks a lot for the advice guys, I really appreciate you took the time. I'll be looking into the bubble jig.

greeting from denmark :)

also great community here!
 
I'm not a jigs-man but I am happy to have a bubble jig.
I see it as a good help to get the feeling to work towards being able to grind free hand with no jigs

also:
"Supported PC Operating Systems: Windows XP, Windows Vista, Windows 7, and Windows 8"
Almost everybody has win10 these days
 
Hengelo_77 said:
I'm not a jigs-man but I am happy to have a bubble jig.
I see it as a good help to get the feeling to work towards being able to grind free hand with no jigs

also:
"Supported PC Operating Systems: Windows XP, Windows Vista, Windows 7, and Windows 8"
Almost everybody has win10 these days
Click to expand...

It's likely supported by 10 as well, as I think Win 10 is backwards compatible with most software designed for the aforementioned op systems.
 
I used a bubble jig for good while, it is a good trainer and helps force you to learn technique in grinding.

Once you learn the concept and technique of starting the grind from the edge and walking it up to toward the spine bit by bit you no longer need the jig.

If you have the same starting and ending point on the blade, top and bottom on both sides , as you grind the angle will end up being the same, on both sides, once you have the flat grind connecting the two.

Use the jig until you fully grasp the concept and technique. Then grinding will flow and be much smoother .
 
I find the Bubble Jig helpful to get the initial flats started, and then I go from there on my own. It just gives me the extra confidence that I'm not going to grind into the spine unwittingly! Thanks Fred!
 
I have bought the SmartJig and it is awesome. Someone had mentioned the USB port facing the grinder. Yes, it's true but it comes with a cover to protect against debris. The jig uses a button to set the reference angle which is the platen's angle. Also, it does support Windows 10. If you are a freehander, this jig would help you a lot.
 
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JosephM said:
I have bought the SmartJig and it is awesome. Someone had mentioned the USB port facing the grinder. Yes, it's true but it comes with a cover to protect against debris. The jig uses a button to set the reference angle which is the platen's angle. If you are a freehander, this jig would help you a lot.
Click to expand...

Is it water proof?
 
No, it is not. The jig sits on the handle and when cooling the blade, you wouldn't dip the handle in water.
 
I use the "belly jig" a lot. It takes a while to build but is free. I came across this discovery while watching my toddler walk around with his belly out one day. I poke my belly out, rest my hands on it and sway with my elbows tucked in. Once the bevel is established things get much easier. Landing a large bevel on the grinder is easy. Once you can establish a flat bevel practice using different amounts of pressure with your fingers to control where you are removing material from. I'll rest the spine on my index finger and put my thumb behind the edge and adjust pressure with those 2 fingers to walk my bevel down or close in on final thickness.
-Trey
 
JosephM said:
No, it is not. The jig sits on the handle and when cooling the blade, you wouldn't dip the handle in water.
Click to expand...

Yes, I do.

When grinding that blank can get hot and the entire blade will get dunked. The heat will travel right up the tang from the blade when you dunk it.
 
i have a bump file guide and i use it now and then for cutting in tang shoulders. i do all other work free hand. if i wass doing gproduction work jigs woudl be an option but i make things at no more then 6 in a set normally now then that said i have been grinding blades for years so i can see how freds angle widget woudlnn be a help getting you used to setting your hand/arm amgles
 
AVigil said:
Yes, I do.

When grinding that blank can get hot and the entire blade will get dunked. The heat will travel right up the tang from the blade when you dunk it.
Click to expand...

In that case, you could mount it on a clamp so you wouldn't get water in it. I have never dunked the tang in water when I do the bevel. The only time I do it is when I am cutting the outline of the knife.
 
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