Best way to hollow grind?

W

weldboss

Joined
Sep 1, 2009
Messages
14
What is the best way to make blade with a hollow gound edge?. Who makes good quality equipment to do it?:confused:
 
The only way to hollow grind that I know of is with a wheel on a belt grinder. Different size wheels are available depending on the radius you want. Many of us use Bader grinders but I started out with a Jet grinder with a 3" wheel.

Gil Hibben has a good video showing how to hollow grind available on his website http://www.hibbenknives.com
 
a curved platten would also work well. making an attachment for a belt grinder out of a still hard and curved leafspring wouldn't be too awfull hard and you would have probably close to a 6-10 foot diameter curve, which would simulate a 6-10 foot wheel :D
Also in this thread wetackle how to make your HG'sconsistant, & I show my set up for hollow grinding, I made my own grinder, including the wheel. http://www.bladeforums.com/forums/showthread.php?t=671555

Hope This Helps:D
Jason
 
You'll want to use a grinder with a wheel, I use a Bader like Mike talked about, many also use the KMG.

Even if I flat grind I use a wheel first, with a platen, curved or flat, you have friction on the back and front of the belt - this means grinding is slower and belts wear out faster due to more heat. The wheel moves with the belt, creating less friction and also uses its own mass through the grind. You can remove stock very fast with a wheel in my experience.
 
Well as far as I know a 10 inch contact wheel is suppose to be the best for hollow grinds. I think blaze orange 60 grit is a little to aggresive for hollow grinds as well . maybee just for a few passes then move on to 100 and so on . Im finding the wider the blade the harder it is to do as well and you cant make as wide of a hollow ghround . I do know this hollow ground knives are easier than flat grinding blades but thats just me.
 
hell gap said:
Well as far as I know a 10 inch contact wheel is suppose to be the best for hollow grinds. I think blaze orange 60 grit is a little to aggressive for hollow grinds as well . maybe just for a few passes then move on to 100 and so on . I'm finding the wider the blade the harder it is to do as well and you cant make as wide of a hollow round . I do know this hollow ground knives are easier than flat grinding blades but thats just me.
Click to expand...

well I would have to say I use a 8" wheel but would like a 10" also for being able to grind wider blades. so we are on the same page about wheel size but i don't agree with your grit choice. its your choice so its not wrong. what ever you want to use is 100% OK by me. i just think that 60 grit is OK for hallow grinding and a 50 is perfect. I just got some 40 grit belts and I'm excited to try them out. I think the reason i like the coarser grit belts is because it removes material fast and grinds cooler. also i don't need to apply as much pressure to the wheel to get a nice deep cut so I'm able to keep a straighter line. now once i rough every thing in i regrind with a finer grit and heat treat. but most all my grinding is done with a 60 or less grit belt. I would say 60 is the highest i would use for hogging. I would really like to get my hands on some 36 grit or even 24 grit blaze belts and really see what thy can do at 9000 SFPM. be then again i am crazy like that. o And all i like to use for hogging is balze belts, there the best in my book. :D:thumbup::thumbup:
 
I find anything coarser than 60 grit hard to control. I rough grind with 60 and then 120 before heat treating. After heat treat, I use 220, 400, 600. If I am going to mirror polish I'll go all the way to 1200 grit.

As for wheel size, I usually use a 8" wheel but you can do two hollow grinds, one above the other, and blend them together for a wider radius.

KongGrind2.jpg
 
I usually start my grinds with an 80, but also will use 50 or 60 if that's what I have around, I feel that the 80 stays sharp a little longer. The 60 is not bad for doing hollows. I would say that the 8" wheel has ground more custom hollow grinds than any other wheel in existence. Once upon a time it was the wheel that came with grinders, period.

I'm also with Mike that you can move your grind higher than the radius of the 8" wheel, just requires practice. Or you could get a 14" wheel, which I adore.
 
You must log in or register to reply here.
Back
Top