Contact Wheel Diameter?

[Dr.Lathe]

I do most of my hollow grinding on small 6"dia. contact wheels. I make mostly small hunters and when I do a big knife it just has a real deep hollow grind! I would like to start doing "full" hollow grinds, top to bottom of blade. I have some 2" aluminum plate that I was going to make the wheels out of, then send them to be rubberized. I would appreciate any input on the use, application and preferences between an 8"dia and 10"dia wheel. I was also considering making the wheel about 1/4" narrower so the belt would hang over both sides evenly to better blend in my plunge area. Both my grinders are powerful enough to run the 10" wheel and I am using 96" belts. Depending on the feedback I might just make one wheel!!!
Thanks in advance......

 

[tom mayo]

as you have mentioned...the biggest problem with a small wheel (to me anything under 10" is small) is that your radius is too small to grind your knives to the top of the blade.....i have made the mistake with even a ten inch wheel of trying to grind a hollow from top to bottom and ended up with the knife so thin in the middle i had to trash it...so we need to watch how wide the blade is in relationship to the radius of the wheel......once one came back from paul bos with a big "bubble" in it...a big thin spot that warped....so with a small wheel you are very limited in how big of a knife you can grind...unless you only grind half way up...which to me defeats the purpose of the hollow grind.in my humble opinion....i have a 12 inch wheel although i seldom use it...i use the 10 inch one almost exclusively for everything......although i also have an 8, 6, 3, 2, etc.....i must add that learning from someone in the bob loveless/los angeles school of knifemakers may have a lot to do with my 10 inch fixation. i would start out with a 2 inch wide wheel and slow make it narrower...bit by bit..instead of making it 1/4 narrower from the get go...might be a little too narrow...just my opinion....i use a square wheel and it tracks very well....i have the tracking wheel built up in the middle with electricians tape...about 1/8" high....helps a lot with keeping the belt where i want it to be...sincerely

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http://www.mayoknives.com




[This message has been edited by tom mayo (edited 02 September 1999).]

 

[Kevin Wilkins]

I would certainly rec. a 10 inch wheel. If you can get a serrated one and a hard rubber one for finish grinding. I don't grind my blades all the way up to the spine but I still think a 10 inch wheel saves a lot of time and trouble. I mean, it's hard enough to get a straight grind anyway.

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www.wilkins-knives.com

 

[george tichbourne]

I use a 14" and a 10 " contact wheel. The 14 is used on knives where I want a flat grind, the arc of this diameter is darned near flat so a couple of strokes with a file and I have a flat grind. The 10" wheel is used on small knives only.

If you can talk your rubber coater into grooving the wheel in a "v" groove pattern you will find it gives less chatter. I have run a lot of different groove patterns in my time and prefer the "v" pattern over everything including the smooth wheel. As for hardness I prefer a 60 Shore"A". It is soft enough to conform but wears well.



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george
www.tichbourneknives.com
sales@tichbourneknives.com

 

[Dr.Lathe]

Thanks guys!
Grinding anything but small knives is very time consuming with the 6" wheel. I like the "Loveless" full grind look and it should perform better for the larger hunters that I am starting to make now.
I thought everyone would say an 8" wheel would be the best all around size, I'm glad I posted this topic!
We have two companies in my area that can do the rubber. I'm going to call them now and find out about he V grooving and the hardness.
I am thinking about making two 10" wheels one serrated and soft, one hard for finishing. I have to find out how much material they will need to put on for each type of rubber. That way I can turn the wheels to the correct size.
Thanks again, this saved me time and lots of aluminum chips!!!!!!