Hollow Grind with a milling machine?

D

drlloyd1

Joined
Jul 12, 1999
Messages
6
I'm pretty new to knifemaking and was wondering is it possible to hollow grind a knife with a milling machine?
Thanks for your opinions.
 
Can be done...large milling head 4" or so, tilt milling head about 20 degrees or so the mill. the tilt angle creates a shallower cut. Going around corners could be difficult.
 
george tichbourne said:
Can be done...large milling head 4" or so, tilt milling head about 20 degrees or so the mill. the tilt angle creates a shallower cut. Going around corners could be difficult.
Click to expand...

thats when yu need cnc programmer like me, curves are my specialty.


oh, a fly cutter set on angle would do the same thing if you dont have large milling head handy.
 
Once again, how do you hold the blade unless you have a magnetic table?
You cannot hold it in a vice or clamp it down on the milling machine table because the cutter will hit the vice or the clamps. If you only clamp the rear end which will become the handle later then the rest of the blade is unsupprted and it will bounce and chatter.In priciple the idea is great but holding the blade is a problem.
Roastelk, ALL men specialize in curves. :D
 
i would take a metal plate, and cut a hole in to it the same shape as the knife, but bit smaller on all sides

then mill a slight lip aroun the inside of the hole, so that the kife sits flush into it. you could then take some hard wood (oak etc) and plane it flat, and proeccd to hollow it out enough to make the knife fit into it. and remeber everythng has to fit verry tight when you clamp it down, the wood will displace a bit as you clamp it down.

ie
top -metal plate
-knive
bottom -wooden block


then just clamp the who set up onto the mill, remeber to take light cuts as you dont want the knife to slip.
 
A whole lot quicker and easier just to pick up your steel, turn on your grinder with a 10" contact wheel and grind it that way. Fast, efficient and virtually no set up time involved. All you really need is to practice, practice, practice. You will get better with time and you will do a whole lot more blades by just grinding than trying to set up a milling machine everytime yo want to hollow grind a blade.
 
Start with an oversize piece of steel, bolt it through the scrap areas onto a base plate and clamp base plate down. Mill the hollow grind THEN profile the blade. Wastes material but using less than optimal equipment never was efficient.
 
Yes Bruce I agree with you about a waste of time but I have a fellow locally with a CNC shop who goes to the trouble of setting up a program and turning out remarkably detailed shaped blades and he brings them to me for polishing.

Why does he do it...he has no grinder but does have a fully equipped CNC shop. And lots of time on his hands when production jobs are running.
 
george tichbourne said:
Yes Bruce I agree with you about a waste of time but I have a fellow locally with a CNC shop who goes to the trouble of setting up a program and turning out remarkably detailed shaped blades and he brings them to me for polishing.

Why does he do it...he has no grinder but does have a fully equipped CNC shop. And lots of time on his hands when production jobs are running.
Click to expand...

also,, some guys can't grind by hand :)
so the next thing would be CNC right :D
 
I understand that a few makers mount opposed grinders, wheels facing each other, turning the face of the wheels, downward, with only a small gap between them. They simply hold the blank edge up and start at the recasso, and pull up and back, hollow grinding both sides at the same time. some authmated factory machines work much the same way. If you are un-able to hand grind, It might be an option. Just a thought. Mike Lovett
 
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