Thought you guys might like to see my new & improved process!

[aarongough]

Ok now I'm waiting for the pick and place unit to transfer the knife through the stations. Then the plate laser, feeder bowls, conveyor systems, multi station rotary dial....

Hah! I would actually have a lot of fun designing that kind of system... Maybe in a few years.

 

[jdm61]

So if its a "hands off" operation the than loading and starting, you can do like 8 blades in an average workday? Accounting for finishing work, how many "machine days" can you do in a typical 5 day week? How many blades can you load onto the mill at one time? How long does it take to for both operations to mill a set of handle scales?

It takes the machine about 30 minutes per side to produce bevels like those you see in the photo.

 

[aarongough]

So if its a "hands off" operation the than loading and starting, you can do like 8 blades in an average workday? Accounting for finishing work, how many "machine days" can you do in a typical 5 day week? How many blades can you load onto the mill at one time? How long does it take to for both operations to mill a set of handle scales?

No, cycle time for all the operations on one blade is right around 2 hours... I have to warm up the machine every morning as well as change tools and so on, so in a typical 8 hour day I get 3 cycles, and therefore I normally do 3 blades in a day at the moment.

Handle scale milling takes around 30 minutes as well, lots of 3D contouring which takes quite a while. Because my machine is older I'm limited to relatively low feedrates (80IPM while 3D contouring). If I had a newer machine I could probably cut the handle milling time down to 10 minutes or so, but it's not a big deal.

 

[Park Swan]

Thanks for sharing all this! Seems very daunting to an outsider so every bit of info gives much perspective.

 

[aarongough]

Thanks for sharing all this! Seems very daunting to an outsider so every bit of info gives much perspective.

No worries at all mate! Parts of this process are a little daunting even to me still, but I'm getting more comfortable with it all the time!

 

[wizzer]

You mentioned hard milling with a more rigid machine. What do you think the advantage to that would be? The ability to get a finer surface finish? More consistent heat treat on a thicker blank prior to machining?

 

[aarongough]

You mentioned hard milling with a more rigid machine. What do you think the advantage to that would be? The ability to get a finer surface finish? More consistent heat treat on a thicker blank prior to machining?

Heat-treat consistency isn't really a concern, my knives are all heat-treated in commercial vacuum furnaces now and the results are really nice!

The advantages that I envision coming from hard-milling are:

1) The ability to have my steel supplier heat-treat the blanks before they surface grind them, which would eliminate any warping and allow them to go to an even higher level of finish on the surface-ground blanks.

2) Because the heat-treat would already be done it eliminates an extra process on my end after the knives are machined, which would make the overall process shorter and smoother with less potential bottlenecks.

3) Hard-milling can produce better surface finishes (as you guessed!). It's quite possible that if I was hard-milling on a more modern machine I would be able to eliminate the need for rough-sanding by hand. I'd probably be able to get a surface finish good enough to start hand-sanding at 400 grit, which would make satin finishes much easier to do!

Even better than hard-milling would be making the knives via abrasive machining... A machine similar to a CNC mill but with a much faster spindle, using CBN coated abrasive pins (instead of an end-mill) would likely be able to turn out some incredible finishes! Machines like this are fairly rare though (google vertical grinding center)... I may look at custom-building a small machine like this in the future, that would be a fun project!