Laser or Water

JTknives

JTknives

Joined
Jun 11, 2006
Messages
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I'm thinking of doing a run of my 2nd Amendment jtwrap knives. picture below for reference. and was going to get a sheet of 8670m from admrial that was 6" x 98" x 3/16th. was thinking of having it water jet cut but then i talked to the boss at work and he deals with this local shop here in Utah that does laser so i gave them a call. gave me a price quote of 2 bucks each, man cant beat that :eek:. asked him about a hardened edge and he said that it will not be very much at all and will be a nice cut. here is there website. http://www.critical-laser.com so my question is this since I'm doing 70 or so knives it seams that i can deal with a little thin hardened edge for 2 bucks each. but has any one used laser be for and had problems, the material is not to expensive but it would be nice to get some input. so what you think

2nd%20Amendment%20side%201.jpg


2nd%20Amendment%20side%202.jpg
 
I looked into it a while back but the local guys quoted me like thirty bucks a piece so I didn't do it
 
wow thats steep, these people seam very very nice. and when doing a bunch a few bucks more or less makes a big different. because I'm trying to be able to sell them for as little as i can to the customers. i would love to be able to sell them for like $125 with a kydex sheath. with the economy how it is money is very precious to people so i thought i would see what i could do by doing a small kinda production run but still hand made just cut out all the grunt work.
 
Did he suggest tempering after laser cutting ? EDM is similar - temper after EDM !
 
Unless you temper, you will lose about 1/16" of all edges, give or take.
With water jet, no loss.
I get one pattern water-jet cut and they clean up with a 400gr belt.
 
he did not say. i am going to clean it up on the grinder after its lasered so it wont be a problem. i think the hardened area is like onley .005 thick or somthing.
 
Water, laser has a much rougher finish and slag.....have done both. I'd go with the water even at a higher cost. (just my opinion).
 
See if they would cut one or two for sample pieces so you can make an informed decision. Do the same with water jet and compare. Let your own judgment decide whether one worth it over the other.

Darren
 
I run a laser and a water jet 5 days a week.

$2 is an outstanding price.

Best advice is: ask for a sample cut of your material.

Also, find out if they are cutting your job with oxygen, nitrogen, or compressed air. You want nitrogen. Oxygen cutting involves more heat, and is characterized by blackened cut edges, and darkened part perimeters. I've never seen a part cut with air, but I assume it's somewhere in the middle.

Generally, if a laser part has slag, than either:
1) the machine is not set-up properly
2) the machine is not working properly
3) the machine is cutting at the limits of its capabilities.
 
I looked at the laser website. The first two lasers they list should be capable of cutting with N2, based on the listed wattage.
 
I operate an industrial cutting laser for a living. I have cut knife blades for a company (sorry, can't say which) out of 1075 before. The amount of area on the periphery that was hardened was less than 0.010 thick. One pass around it at the grinder to clean up the edge and it's gone.

There are many variables, so I will speak about what I have cut with my machines. Properly setup, the main difference between oxygen cut and nitrogen cut is whether or not there is an oxide layer at the edge. Either one will generate heat, and the parts that I've cut and tested have shown about the same amount of haz (heat affected zone). Steels with higher carbon content also cut a bit differently with oxygen than with nitrogen.

I've cut quite a range of materials and thicknesses. I'd disagree that a laser cut is rougher and always has slag. I have had to cut parts for a local waterjet place because their finish was too rough. My parts rarely have slag.

I agree that the price is really good, a sample is a must have. If you can compare the two, even better.

Patriqq, I've cut parts with compressed air. It's best described as a nitrogen cut that's almost completely cleaned up. Not quite as clean, but almost. The downfall is that it's tough on optics. Utlimately I found it not to be worthwhile for me and haven't used it years.

Jamie
 
JT,

That is a great looking knife (awesome wrap) and this thread has a lot of valuable information.

You type pretty good with one hand!

kimsalls
 
i thank one reasion im leaning twords laser is because its local which is a huge plus when doing a bunch of knives. i dont mind a little clean up i just am not in the mood to hog out that many blades.
 
Look out for that lanyard hole.

I cut a test hole with O2 in 3/16" 1075 (our laser is 2500 W - we can't cut 3/16" steel with N2) and a HSS counter-sink couldn't touch it.

So if you plan to have your lanyard hole laser-cut, have them put a hole in your test sample. Then, try to countersink the hole.

If you have a problem, one option is to have the laser shop put a pierce (only) at the center of the hole. The pierce is like a center-punch mark - you drill it out. We do that on 3/8"+ steel when we are tapping threads: we either laser a pierce, or an under-sized hole and drill it out prior to tapping.
 
patriqq said:
Look out for that lanyard hole.

I cut a test hole with O2 in 3/16" 1075 (our laser is 2500 W - we can't cut 3/16" steel with N2) and a HSS counter-sink couldn't touch it.

So if you plan to have your lanyard hole laser-cut, have them put a hole in your test sample. Then, try to countersink the hole.

If you have a problem, one option is to have the laser shop put a pierce (only) at the center of the hole. The pierce is like a center-punch mark - you drill it out. We do that on 3/8"+ steel when we are tapping threads: we either laser a pierce, or an under-sized hole and drill it out prior to tapping.
Click to expand...

i would most likley use a cabide countersink so hardness would not be a problem. i am going to give them a call right now and find out about there lasers and what i could get as a test piece.
 
Can you tell me which is which? Just to make it easy, waterjet is on the left and laser to the right. Both are 1/4". And thats my medium quality cut. You will have a Heat Affected Zone on the laser. If you don't mind the negatives of laser, I say go for it. $2 each is cheap. Just be ready for what you get. You will get what you pay for. JT, don't cheat yourself by selling you knives for $125. I think they are better than that! ;)
ry%3D480

ry%3D480
 
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