Water jet prices....

Look at waterjet as a time and material saving bandsaw.
You never get a finished edge from the bandsaw, and you shouldn't from the waterjet either.
 
Self Made Knives said:
JM, are you talking about the kerf being wider on the top side? Like a hole that is 1/4" on top, but tapered inward towards the bottom? I asked about that too when I was getting quotes and a couple of guys say that shouldn't be a problem anymore. Supposedly, some older systems and less skilled operators left tapered kerfs, but they are telling me shouldn't be like that these days.
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Yes. Perhaps my problem is that if you claim that your newest and greatest gear eliminates that tapered kerf completely and yet i am holding one of your demo pieces in my hand and seeing that very taper, i am a bit perplexed and that doesn't do a lot for my confidence in your work. :3:
 
Brian, i don't expect perfect smooth, even polished looking edgesfrom anything using abrasive material and high pressure water like you would get with a wire EDM setup, but I would like something resembling a 90 degree angle. :lol: In the one job that I had done, I noticed a difference in how much the edge varied from that perfect 90 depending on how fast the cutting head could be run. IIRC, the spots were the machine had to slow down for replaces cuts were better tan say the long run of the edge or spine where it could go faster.
Fellhoelter said:
Look at waterjet as a time and material saving bandsaw.
You never get a finished edge from the bandsaw, and you shouldn't from the waterjet either.
Click to expand...
 
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They can get close to a zero draft angle, but have to run SLOW.
We pay by the minute, so price increases exponentially. ($8 part becomes $24...)
Knifemakers are notoriously cheap and are not willing to pay for that.
Nor should they, since you have to clean it up anyhow!

In my world at least, it's a non-issue, and I have 95% of my parts cut on the waterjet.
 
Fellhoelter said:
I have 95% of my parts cut on the waterjet.
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Ever have any cut with laser? When I placed my order with the laser guy, he gave me a shop tour and one of the first things I was drawn to was the scrap bin at the end of the laser cutter. Guy probably thought I was nuts digging through dumpster. I picked through aluminum, galvanized sheet metal, steel of various thicknesses, etc. The aluminum parts came out kind of rough looking, but all the steel parts of a thickness similar to a knife looked awesome to me.

For comparison, on my survival knife design, I've been milling a 3/8" slot about 3" long in the handle. The chatter left from the end mill is way rougher than edges left by the laser. Now, if all these pesky holidays would hurry up and get past us, maybe he'll get to cutting my order!
 
Yeah, as most of the quotes I have seen are by the piece, speed would be a cost issue for them. I guess it is a question of telling your vendor exactly what you expect as opposed to just accepting general representations that it will be what you want and then seeing if it is worth the extra money.. It is really only a significant issue in REALLY tight spaces where they have to go slow anyway. I guess my feeling is that if it sin't going to be straight, don't tell me that it is going to be straight. I am willing accept the less than zero draft angle being minimized if the price is right but tell me that up front. :biggrin:
Fellhoelter said:
They can get close to a zero draft angle, but have to run SLOW.
We pay by the minute, so price increases exponentially. ($8 part becomes $24...)
Knifemakers are notoriously cheap and are not willing to pay for that.
Nor should they, since you have to clean it up anyhow!

In my world at least, it's a non-issue, and I have 95% of my parts cut on the waterjet.
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Fellhoelter said:
Then you need to re evaluate your procedure!
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Yeah, I guess I should've said, when I try to get the slots milled fast, hogging it out, leaves chatter marks. I can increase the cutter speeds and slow the feed down and get a good finish. I cut the last batch of 4 out of one bar and was pushing is as fast as I could to try and get the blanks roughed out in the least amount of time. This interior slot isn't seen in the finished product, so I was just focusing on speeding the process up. But, anyway, have you tried laser for a comparison? I want to try the water jet next time so I can see the difference.
 
I have, but only once, and I didn't like it.

I may have had a bad vendor too.

It's tough to find good vendors.

I think I am on waterjet guy #6
 
Fellhoelter said:
I have, but only once, and I didn't like it.

I may have had a bad vendor too.

It's tough to find good vendors.

I think I am on waterjet guy #6
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Brian,
I went though 3-4 before Bubba-San told me about Jay at http://www.waterjettech.com/ContactUs.html

No setup fee and he wanted to be so sure that everything was right before he did the cuts. He also does work for Boeing and Caterpillar in his state so he has a clue!.

I am having another full sheet of Stainless sent to him on Monday for a few of my patterns he has on file. I buy the steel from the Mill/Supplier and have it shipped direct to Jay.
For any of you new guys, this is how to keep shipping costs down so the steel doesn't backtrack across the country.
 
Yeah, shipping big plates of steel can get a pit spendy. :what!:
rhinoknives said:
Brian,
I went though 3-4 before Bubba-San told me about Jay at http://www.waterjettech.com/ContactUs.html

No setup fee and he wanted to be so sure that everything was right before he did the cuts. He also does work for Boeing and Caterpillar in his state so he has a clue!.

I am having another full sheet of Stainless sent to him on Monday for a few of my patterns he has on file. I buy the steel from the Mill/Supplier and have it shipped direct to Jay.
For any of you new guys, this is how to keep shipping costs down so the steel doesn't backtrack across the country.
Click to expand...
 
Waterjetting cuts nearly always have a draft (angle of cut).

30Kpsi jets tend to have a larger draft than say a 60kpsi jet. This also depends on degrees of axis the jet has. If it is a 2d jet, it's going to have a draft - even at slow speed. This is just something you clean up as part of the fabrication process.

A 5 axis jet can move the head to an angle to take into account the draft and minimize it. Generally, higher pressure jets make cleaner cuts but cost more.

A waterjet is made to blow it's self up and they always do. Ask anyone that owns one. They hate them cause they break down so much but they do things that can't be done otherwise. I hate them and I don't even own one. I have waterjet work done every month or more often.

Edge cuts are rated Q1-Q5. The nicer the edge (Q1), the more it's going to cost. This rating is completely arbitrary and one jet operator may have an standard of Q2 cut that is another operator's Q4 quality. The less draft and finer cut quality you ask for, the more it's going to cost. It is your job to specify the quality of cut or you are going to get a Q3/Q4 - what ever that is. If you hammer the jet operator on price, the cut quality is going to go down. These guys have software that tells them exactly the cost of operating their equipment. They know to the penny what they can charge and make money. Pricing a job to a customer after they have the cost of operating is a business decision they have to make. Some make good decisions and stay in business, others make poor decisions and struggle for business or "retire" from waterjetting. Replacement parts are expensive. Abrasive material varies by jet operator choice and is often driven by material being cut. This can also affect quality of the cut.

Every water jet operator knows about draft of cut but usually doesn't communicate it that well. Not on purpose, it's just generally understood there is going to be a draft to the cut and they expect the customer (right or wrong) to have some awareness of that. It's always a shock to some one brand new to waterjet cutting the draft can be so pronounced and the edge cut quality can be ragged. You get what you pay for. Brian is dead on in his comments about cost/quality/willingness to pay.

You can specify cut quality around different parts of the blade blank. The jetting software will do this but it's up to the operator to charge/sell this variable quality of cut. Cutting knife parts can be a good business for a water jet guy but it's most often not enough to keep the machine busy. It's hard to find a jet operator that understands what a knife maker wants and is willing to charge for what a knife maker is willing to pay.

If you ask a waterjet guy to cut 5 blade blanks, he doesn't even want to talk to you. Seriously. He can't set up the job, fix the CAD -if there is one, nest them, diagram the cuts, manage the shipping in and out of materials and product, billing, phone calls discussing your dream design, etc and make money charging you $40 or $50. Start at 50 blanks and you will have their attention -- or at least some of them.
 
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Boss, those are exactly the things I heard and discussed with the 3 local water jet guys around here. Except, no one tried to turn me away due to quantity really. I had a 6"x36" sheet of O1 which would yield 16 blanks and they were all ok with that. I didn't really ask if the price was adjusted up for such a small order, didn't think of it, but the quotes were all around $9+.

The laser guy I'm going with does have a minimum shop charge of $150 which meant I had to bring a 12"x48" sheet of steel to him to get $150 worth of blanks, 42 I think. He did tell me he wasn't interested in smaller sized material, like 2" wide sticks, even if I had a bunch of them, too much set up. I'm on pins and needles waiting on my sheet to get cut, but he did tell me he has a backlog of work and that it would be a while.

At $3.80 or so per blank, its less than half of water jet prices. Water jet would have to be pretty awesome for me to pay twice as much for it.

EDIT: Right after I hit post, laser guy called and said they're cutting my stuff today. Maybe I'll have pics tomorrow.
 
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All right guys, picked up my laser cut blanks today! I took a bunch of pics and I'll try to describe them, but I want your feedback on how you think this compares to water jet parts. Overall, I am very happy with them, got 37 blanks cut for $145, or about $3.92 each. I had nested the parts myself and felt that 43 could've been cut, but laser guy said I had them too close and re-nested them. In fact, he told me in the future not to nest them, he just wants an individual part drawing.

So, here's how they came home. They were all rolled up in paper, in bundles of 5 and in a way that there was no metal to metal contact.
SAM_2027.jpgSAM_2029.jpgSAM_2033.jpg

Draft and hole sizes were one of my first concerns, first pic shows a very tiny draft. We're talking 0.005" maybe. Checked holes with drill bits and you can see how tightly they fit. Actually, it almost looks like there is no draft to the holes, at least I couldn't figure out a way to check it.
SAM_2046.jpgSAM_2043.jpgSAM_2045.jpg

Here's some close ups of the jimping.
SAM_2038.jpgSAM_2041.jpg

And finally, I tried to show a comparison of the milled blanks I've been making vs. the laser to show a cut quality comparison. The blank in front is laser, behind that is one I just roughed on the mill. Pretty close to the same.
SAM_2056.jpgSAM_2064.jpg

I have timed every step of profiling, milling, drilling, and filing jimping on my survival knife and I always average over an hour each. I think a conservative estimate on the time the laser is saving me for this batch is at least 40 hrs. of work. Not to mention drill bits, end mills, and my sore elbows. I think I can debur and clean these up in about 5 minutes each.
 
Looks like the laser is a good option. I have a local shop with a laser and plan to do the same as you in the near future.
 
They appear to have been done very well. I really like your drop point Hunter design by the way!

Cleaning up the jimping may be a pain? Not sure how you planned to do that? Are you planning on using the butt of the knives for thumb purchase? Its late, and I don't see where that is going??
 
The jimping on the butt of the knife is there for pounding or breaking something. Nutcracker? At least that's my thinking. It also just adds a decorative look to what might be a plain looking butt. I sized the jimping notches to correspond with a round file, so I'm hoping just a stroke or two with the file will finish them. These blades are also media blasted and oxidized black in the end. There's a lot more to these than meets the eye that I haven't really shared.
 
Wow they look like they did a good job. How does the Lazer effect the edges that have been cut does it harden them or anything?
 
One the guys posted above that there's about 0.015" affected. I planned ahead for the cutting edge, but everywhere else is final dimension. It was a out 10 degrees last night in my shop, so pics were all attempted so far.
 
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