Waterjet knife making?

[jac_solar]

I was thinking, as CNC machines are getting cheaper, I wonder if someone will come up with a cheaper waterjet solution, and if that will be viable for knifemaking? Wouldn't it be possible to just buy a bunch of heat treated steel plates and make a bunch of knives with a waterjet?

If it is possible (And doesn't ruin the heat treat.), knife making could become a lot easier (Well, if learning CAD software is easier than the current process of making a knife. Whether or not that is a good thing is up for discussion).

Take a look at some of the 5-axis water jet stuff:

http://www.thefabricator.com/article/waterjetcutting/2-d--3-d--5-axis-waterjet-cutting

http://blog.wardjet.com/2011/05/video-5-axis-bevel-cutting-with-height.html

http://www.wardjet.com/applications.html

With recent advances in control and motion technology, 5-axis water jet cutting (abrasive and pure) has become a reality. Where the normal axes on a water jet are named X (back/forth), Y(left/right) and Z (up/down), a 5-axis system will typically add an A axis (angle from perpendicular) and C axes (rotation around the Z-axis). Depending on the cutting head, the maximum cutting angle for the A axis can be anywhere from 55, 60, or in some cases even 90 degrees from vertical. As such, 5-axis cutting opens up a wide range of applications that can be machined on a water jet cutting machine.

http://en.wikipedia.org/wiki/Water_jet_cutter

By using this, you could program extremely complex (Or just precise.) bevels and shapes, and basically get a finished knife out of a single model in CAD.

 

[kornphlake]

For custom work I suppose cutting pre-hardened stock on a water jet might be viable, but wire EDM would probably be a better technology. In a mass production environment, I don't think water jet would be as repeatable or reliable as conventional machining methods.

 

[jac_solar]

For custom work I suppose cutting pre-hardened stock on a water jet might be viable, but wire EDM would probably be a better technology. In a mass production environment, I don't think water jet would be as repeatable or reliable as conventional machining methods.

A water jet would be significantly more reliable and repeatable, as long as you have the same CAD file and similar steel, though..

The kerf, or width, of the cut can be adjusted by swapping parts in the nozzle, as well as changing the type and size of abrasive. Typical abrasive cuts have a kerf in the range of 0.04″ to 0.05″ (1.016 to 1.27 mm), but can be as narrow as 0.02″ (0.508 mm). Non-abrasive cuts are normally 0.007″ to 0.013″ (0.178 to 0.33 mm), but can be as small as 0.003″ (0.076 mm), which is approximately that of a human hair. These small jets can permit small details in a wide range of applications.

Water jets are capable of attaining accuracies down to 0.005″ (0.13 mm) and repeatabilities down to 0.001″ (0.025 mm).[30]

It's not as efficient or as fast as regular production methods though, I imagine.

Wire EDM sounds interesting -- I don't think I've heard of it before. But using that would limit the possible designs - ie, internal bevels, shapes, and so forth. Like the upper shape on the Zero Tolerance 0777:

It also seems like you couldn't use that on heat treated steels?

The electric discharge heats a small portion of the work-piece to thousands of degrees.

http://todaysmachiningworld.com/magazine/how-it-works-wire-edm/

Don't know about the costs, wear rate, etc. compared to a water jet, but I would imagine that the wear rate is significantly higher. A water jet seems to be much more straight-forward compared to an EDM machine.

 

[nutellarain]

Wouldn't this be more troublesome for production folders? The way they're made is by stamping the general pattern, heat treating, and sharpening it. For custom makers it probably would defeat the purpose, as you usually want your custom handforged.

 

[Morrow]

Wire EDM, laser cutting and CNC machining are all already being used by production knife manufacturers, mid-tech and some custom knife makers. We have service providers on this site that will take a sheet of steel and cut knife blanks for you.

Take a look at this thread.

http://www.bladeforums.com/forums/showthread.php/845359-Formal-Introduction

 

[jac_solar]

Wouldn't this be more troublesome for production folders? The way they're made is by stamping the general pattern, heat treating, and sharpening it. For custom makers it probably would defeat the purpose, as you usually want your custom handforged.

Yeah, I don't think this would be any good for production companies - I was thinking of someone interested in making a knife.

 

[S.Grosvenor]

As a business owner 11yrs, any expense has to be directly tied to ROR (Rate of Return) meaning, If I pay $10,000 for a piece of equipment how many products at what price do I have to make before simply breaking even, let alone actually making a profit. Also will the product it produces actually be something that will sell so I can build a ROR table?

Hard to spend thousands and thousands of dollars on a piece of equipment to make 1 of pieces. Although the options would be nearly endless I think these machines are meant for full on production.

 

[jac_solar]

As a business owner 11yrs, any expense has to be directly tied to ROR (Rate of Return) meaning, If I pay $10,000 for a piece of equipment how many products at what price do I have to make before simply breaking even, let alone actually making a profit. Also will the product it produces actually be something that will sell so I can build a ROR table?

Hard to spend thousands and thousands of dollars on a piece of equipment to make 1 of pieces. Although the options would be nearly endless I think these machines are meant for full on production.

Yeah, but as I said;

I was thinking, as CNC machines are getting cheaper, I wonder if someone will come up with a cheaper waterjet solution, and if that will be viable for knifemaking? Wouldn't it be possible to just buy a bunch of heat treated steel plates and make a bunch of knives with a waterjet?

If it is possible (And doesn't ruin the heat treat.), knife making could become a lot easier (Well, if learning CAD software is easier than the current process of making a knife. Whether or not that is a good thing is up for discussion).

I was just thinking of the possibilities of homemade waterjet solutions - if it became cheaper, if someone came up with a solution that drastically cheapened water jets, etc.

 

[Cereal_killer]

I gotta say, as a machinist myself- that H2O jetted impeller is very impressive!

 

[gooeytek]

There are already a lot of "custom" knifemakers that get this done. All they have to do is grind the edge, screw the folder together, sell it for thousands. It's become a big joke, really.

 

[kornphlake]

A water jet would be significantly more reliable and repeatable, as long as you have the same CAD file and similar steel, though..

Water jets are less precise than conventional cutting, meaning milling, grinding, turning, etc. Modern lasers are now repeatable to within a few ten-thousandths of an inch which is beyond the precision of water jet machines. A CAD file doesn't make a quality part, I can make a quality part with a hand drawn sketch and a manual machine as easily as I can make a garbage part on a CNC machine with a CAD file, the experience and skill of the machine operator/programmer are what make a quality part, not the equipment. That said certain cutting technologies are inherently less precise, for example a table saw is more precise making long straight cuts than a sawzall. In metal fabrication a water jet is a sawzall, a versatile, easy to use piece of equipment, but the resulting cuts are not as precise as cuts made using other machining technologies. Water jet technology has improved but so have other technologies. Water jet is still the red headed stepchild of the machining world.

It's not as efficient or as fast as regular production methods though, I imagine.

The strength of water jet technology is its ability to cut materials like ceramic, stone and plastics that have either a very high or very low melting point that makes laser cutting un-feasable. Machining speeds are similar to laser cutting.

Wire EDM sounds interesting -- I don't think I've heard of it before. But using that would limit the possible designs - ie, internal bevels, shapes, and so forth. Like the upper shape on the Zero Tolerance 0777:

Lasers, water jets, wire EDM, plasma cutters, even bandsaws all have the same capabilities as far as part geometry is concerned. None of these technologies could cut the longitudinal groove in the 0777 blade, any of them can however cut the jimping if that's what your calling an "upper shape"

It also seems like you couldn't use that on heat treated steels?

The primary use of EDM technology is cutting hardened steels, including tungsten carbide and polycrystalline diamond, they're used extensively in making molds and dies. The heat affected zone or "recast" can be as thin as .0001" with proper machining practices and parameters.

Don't know about the costs, wear rate, etc. compared to a water jet, but I would imagine that the wear rate is significantly higher. A water jet seems to be much more straight-forward compared to an EDM machine.

Cost to operate a wire EDM is higher than the cost to operate a water jet, but if I'm reading correctly you really didn't know that you were guessing, programming, setup and longevity of either machine are comparable. The cost of a wire EDM buys higher precision; the ability to make parts that are closer to the theoretical size consistently.

 

[kornphlake]

I gotta say, as a machinist myself- that H2O jetted impeller is very impressive!

It's impressive, but as far as I can tell it's a cosmetic piece only, I'd be more impressed if the tolerances were +/-.0005" According to the wikipedia article linked, accuracy is only +/-.005." Typically when I see a claim like that I assume it's under ideal laboratory conditions and in the real world it will be closer to +/-.010. There's no claim specificly concerning the precision of the impeller, it might be +/-.020"

 

[jac_solar]

Water jets are less precise than conventional cutting, meaning milling, grinding, turning, etc. Modern lasers are now repeatable to within a few ten-thousandths of an inch which is beyond the precision of water jet machines. A CAD file doesn't make a quality part, I can make a quality part with a hand drawn sketch and a manual machine as easily as I can make a garbage part on a CNC machine with a CAD file, the experience and skill of the machine operator/programmer are what make a quality part, not the equipment. That said certain cutting technologies are inherently less precise, for example a table saw is more precise making long straight cuts than a sawzall. In metal fabrication a water jet is a sawzall, a versatile, easy to use piece of equipment, but the resulting cuts are not as precise as cuts made using other machining technologies. Water jet technology has improved but so have other technologies. Water jet is still the red headed stepchild of the machining world.





The strength of water jet technology is its ability to cut materials like ceramic, stone and plastics that have either a very high or very low melting point that makes laser cutting un-feasable. Machining speeds are similar to laser cutting.



Lasers, water jets, wire EDM, plasma cutters, even bandsaws all have the same capabilities as far as part geometry is concerned. None of these technologies could cut the longitudinal groove in the 0777 blade, any of them can however cut the jimping if that's what your calling an "upper shape"



The primary use of EDM technology is cutting hardened steels, including tungsten carbide and polycrystalline diamond, they're used extensively in making molds and dies. The heat affected zone or "recast" can be as thin as .0001" with proper machining practices and parameters.




Cost to operate a wire EDM is higher than the cost to operate a water jet, but if I'm reading correctly you really didn't know that you were guessing, programming, setup and longevity of either machine are comparable. The cost of a wire EDM buys higher precision; the ability to make parts that are closer to the theoretical size consistently.

Yeah, I meant the groove. Since a waterjet can, according to the wikipedia page, cut up to 90 degrees sideways, and cut materials over 18 inches thick (Probably not as much with steel of course.), I thought it'd be possible to make grooves like that (The groove would go through the entire work piece, though, of course.) - or I thought it might be possible to even cut grooves halfway through (As in, not through the entire length of the piece; stopping halfway through.) by use of the "height sensor". If it's possible to predict the exact cutting speed, is it not possible to stop cutting halfway through?

 

[NCCNC]

I can tell ya right now that a 5 axis waterjet that will cut 90 degrees is gonna be well over a million, and getting some jet time at a shop with a 5 axis is going to be CRAZY expensive. Also, the tolerances are going to be around +/- .015. EDM's are going to produce the best tolearance (our sinker and wire EDM's cut within .00005) but they burn incredibly slow, much less than an inch per minute for knife blade thickness material. CNC mills are much faster than either of the other options as far as detail. Now for straight up knife blanks, waterjets are the way to go. I will post a nasty cutting video up tommorow, of how fast a jet can cut in thin material with some high quality garnet pumping through its veins.

 

[jac_solar]

I can tell ya right now that a 5 axis waterjet that will cut 90 degrees is gonna be well over a million, and getting some jet time at a shop with a 5 axis is going to be CRAZY expensive. Also, the tolerances are going to be around +/- .015. EDM's are going to produce the best tolearance (our sinker and wire EDM's cut within .00005) but they burn incredibly slow, much less than an inch per minute for knife blade thickness material. CNC mills are much faster than either of the other options as far as detail. Now for straight up knife blanks, waterjets are the way to go. I will post a nasty cutting video up tommorow, of how fast a jet can cut in thin material with some high quality garnet pumping through its veins.

Cool. This was more of a post about the possibilities of water jets in knifemaking if it became cheaper, though, so I rephrased my post:

I was thinking, as CNC machines are getting cheaper, I wonder, if someone came up with a cheaper waterjet solution, could that make it viable for homemade knifemaking? Wouldn't it be possible to just buy a bunch of heat treated steel plates and make a bunch of knives with a waterjet?

 

[james terrio]

Wire EDM, laser cutting and CNC machining are all already being used by production knife manufacturers, mid-tech and some custom knife makers. We have service providers on this site that will take a sheet of steel and cut knife blanks for you.

Take a look at this thread.

http://www.bladeforums.com/forums/showthread.php/845359-Formal-Introduction

Yes indeed, lots of companies and handmade guys have their blades profiled by water jet, clean up the profiles, grind the bevels and then HT. Holes typically need to be re-drilled or reamed. It's a pretty efficient way to build knives, and still allows a high degree of hand work/customization.

They would have to get awfully cheap to make it worthwhile for very many individual makers to have them in their shops. There's a good deal of training and skill involved in setting up, running and maintaing a WJ. It's not something you just plug in, press a button and *poof* out pops a knife Frankly it just makes more sense for a guy like me to have a pro shop do the WJ cutting, while I spend my time grinding bevels and so forth. It's not a huge money-saver, but it does free up the maker's time. I assure you, standing over a bandsaw cutting out blades all day is not much fun.

As for completely crafting blades, there are still some limitations even with the high-end stuff shown above. I don't think you could get a hollow grind or convex blade that way, for instance.

There are already a lot of "custom" knifemakers that get this done. All they have to do is grind the edge, screw the folder together, sell it for thousands. It's become a big joke, really.

Man, I wish it was as easy as you make it sound. If you really think "just grinding the edge" is a big joke, I invite you to give it a try

 

[knarfeng]

I was thinking, as CNC machines are getting cheaper, I wonder if someone will come up with a cheaper waterjet solution, and if that will be viable for knifemaking? Wouldn't it be possible to just buy a bunch of heat treated steel plates and make a bunch of knives with a waterjet?

As Morrow said, waterjets are already being used by large knife manufacturers who own their own units. They are also used by custom knife makers who send their designs to a job shop to be cut.

I would not expect the price to come down to the point where a small one or two man custom shop could own one any time soon.

 

[gooeytek]

Man, I wish it was as easy as you make it sound. If you really think "just grinding the edge" is a big joke, I invite you to give it a try

There was no disrespect intended whatsoever, JT. It's definitely easier than doing the whole knife yourself, no? Would you sell a folder that you only ground the edge on, for a couple grand? I know many knifemakers who do it all by hand, and sell their knives for what a high-end production or midtech costs. Which type of "custom" should be worth more?

 

[james terrio]

No offense taken

It's definitely easier than doing the whole knife yourself, no?

Profiling blades requires the least skill of any step in the process. So in my view, having blades WJ cut has no impact on the value of the knife.

Which type of "custom" should be worth more?

That's a whole other can of worms. A knife is worth whatever someone will pay for it.

 

[idaho]

No offense taken



Profiling blades requires the least skill of any step in the process. So in my view, having blades WJ cut has no impact on the value of the knife.



That's a whole other can of worms. A knife is worth whatever someone will pay for it.

I find watejet (laser in my case) very usefull. I'm not a knifemaker, but i sometimes like to design and make a knife for me or a friend - throwing knives recently.

I just draw knives, send drawing to shop, and get them after few days. I just grind the tips with hand grinder - like 5 minutes each, and they are ready.
I will be doing more knives this way. Laser cut, send to one knifemaker to make grinds, and to other to make handles.
They will not be custom class pieces, but they will be my designs.