Cut it out!

Lorien

Lorien

Nose to the Grindstone
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Knifemaker / Craftsman / Service Provider
Joined
Dec 5, 2005
Messages
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Hey howdy!
Anyone out there care to share their thoughts and/or experiences with regards to outsourcing cutting?

All and any kind of thing related to your experience with waterjet, laser, cnc, edm, etc. is what I'm angling for. Pretty broad topic!

Cheers!
 
If and when I ever settle on a "standard pattern" I am considering waterjet. Alternatively, since I like to experiment with blade/handle combinations, I have thought about having the handle waterjet cut with a rectangular "blank" for the blade.

Many years ago I tried laser cut, and the edge was hard, so I dropped laser cutting from my option menu. Waterjet seems the most cost effective.
 
Depends on the work method. I'm in for laser as it's cheaper. Surface roughness is almost double than water, but I leave 1/2mm for final shaping which is after prequenches and before quench. Edge and tip is shaped after HT. Hardened layer is dealt with in speed anneal (<20min) before quench so it's no issue. Scales ground to shape before quench.
If cut hardening is an issue, water is king. Grinding off the hardened layer after laser requires time.
CNC is the best as all is in tolerance, but is almost most expensive. It's worth considering if the knife is a grand or more.
EDM is great but most expensive. No need for those tolerances in a knife. Maybe for a flipper.
 
I used njsb for water jet for 2 patterns. I sent down templates, $30 to make the cut files and got 30 blades (8 magnacut and 22 Nitro V, all 1/8"), for a reasonable price. It took around 2-3 hours to fully prep out the blades for HT vs 2 days the last time I did a batch of less blades. Well worth it if you have a pattern you like! Inised to send rectangles out for HT with 1 hole drilled to hang for cryo and when people ordered, did the profiling and stuff and used carbide for the other holes. Hardened rectangle to finished knife in an 8 hour day or less typically!
 
Leading Edge has cut quite a few parts for me. Water jet for steel and laser for nickel silver.
Mark does a great job!
 
I think it all depends on volume, low volume waterjet can be great if you want edges to be cleaner but you still often have clean up due to biased cuts, good laser cutting can be cleaned up just as quickly as a waterjet blanks and is significantly cheaper depending on your area, as an example I tend to buy steel in full size sheets, recently got a few 24”x36” sheets of magnacut in 1/16” and 3/32” thickness. Had two sheets of 1/16” stock laser cut and got a total of 95 blades cut from the two sheets, cutting cost ended up being $2.50 per blade. Pricing seems to vary considerably so you may have to shop around a bit and it’s almost always easier to look in your local area first as you may get better pricing or convenience of drop off and pick up. For me it makes sense to go with a good laser cutter for higher volume as I’m going to clean the profile anyway regardless of how the blades are cut (I grind the edge clean pre-ht and ream pin holes, handle and spine naturally gets cleaned up during the handle shaping/finishing steps) if I was a hobbyist NJSB has a great waterjet service and it’s simple to get everything cut and handled in one shop it just costs a bit more. I still like to have a good saw to use for prototype work/odd patterns or if I’m just in between dropping of material to be cut. I don’t have any experience with wire edm or cnc cut parts but if I was going to have blade profiles cnc cut I’d just have the entire blade roughed/finished out on the cnc, plus if I needed that type of tolerances I’d likely just invest in my own cnc mill.
 
thanks for the great feedback.
I have a few patterns that'll be going to an acquaintance who has a waterjet in his fab shop, once another friend helps me get my hand drawn sketches formatted into files the machine can understand. One of them is a dagger, and I'm the most excited about that since I'll be starting with symmetry.

When the stars align, my next machine purchase is going to be a mini mill. Strikes me that finishing the profile on waterjet blanks with a machine like that is the way to go.
 
Finishing waterjet-cut profiles is best done by hand on a belt grinder.
Programming a CNC mini mill to finish profiles is the same as programming it to just fully cut them out.
 
I want a mill more for small stuff, like jimping, inside surfaces, choils, stop pin channels, precision holes and such- getting those surfaces true while preserving the as designed tolerances , after waterjet, as much as possible.
I use my drill press for that kind of thing now and it really is not the right tool for the job, poor thing.

the one thing about waterjet that I guess has me looking for other options, is that bias to the cut. I'm going to ask my guy about this, but I'd want to ensure that the bias wouldn't undercut parts of the design that need to be dead nuts, and I'd need to know the tool path and which direction the bias goes etc or whatever.

I have a lot to learn wrt technical parameters of outsourcing components of the process. It's tough to beat the accuracy you can get with a 2x72, a saw and a drill press- but you just can't get the repeatability that you can with mechanized cutting, and some form of milling thereafter.

Time to look into taking some courses👍
 
right now my "repeatbility" is rough profiling, drilling holes, then super glueing all the blanks of the same design together and chasing the profile on the belt grinder....lol.
 
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