What size of contact wheel

A

alexmin

Joined
Nov 16, 2005
Messages
513
Main reason I want a contact wheel now is because profiling on flat platen is pain and wears my piroceram platen fast.

Eventually I want to try hollow grind too. What contact size wheel is more practical for these two purposes in your opinion?

Thanks,
Alex
 
Probably the most popular sizes are 8 and 10 inches. A few years ago, it appeared the 8 inch was more popular, and now it appears the 10 inch may be.

Craig
 
Yep! It used to be the 8" as the most popular...but now I ship way more 10".

I can't stress enough....there are a million other useful ways to use a contact wheel ...other than hollow grinding. Contact wheels are much more efficient that the platen attachment. They require less hp and give you much better belt life. They remove material faster and easier with better finishes.

But they don't make things flat. So you still need the platen.
 
rfrink said:
Yep! It used to be the 8" as the most popular...but now I ship way more 10".

I can't stress enough....there are a million other useful ways to use a contact wheel ...other than hollow grinding. Contact wheels are much more efficient that the platen attachment. They require less hp and give you much better belt life. They remove material faster and easier with better finishes.

But they don't make things flat. So you still need the platen.
Click to expand...
But they don't make things flat. So you still need the platen
Click to expand...

Rob remember we can flat grind on a contact wheel also ....I'm not talking about a contact wheel surface grinder but the principle applies to the same grinding vertically on a vertical wheel:)
 
Good point Dan.....that makes 1 million and 1 uses for the contact wheel. This reinforces my point...that contact wheels are good things.:thumbup: :thumbup:
 
I made my own contact wheel a couple of years ago.
I wanted it to be 8". Sadly, I did not think of the obvious and made the wheel 8" and forgot that it still has to get the polymer "tire", I kinda had 8" stuck in the brain.
Long and short of it is that after the polymer I ended up with a 9" wheel.:o
Ah well, it is different.:D

Mike
 
Bruce Bump said:
I want at least a 24" wheel. I like a hollow grind that is almost flat.
Click to expand...

Definitely. Hey Rob, whatever happened to that big wheel grinder you were developing?
 
About giant-size wheels for hollow-grinds. You can make a curved platen
to achive that hollow-yet-almost-flat grind, w/o having to spin a 20" monster :)

And lookup a recent post of mine where I pointed out a 12" (?) steel contact
wheel for $6 - there's still plenty left.
 
For profiling and most bevels I use a 10" wheel. I use an 8" also for certain things, like hollow grinding tangs preparatory to tapering them and false edge bevels, and the bevels of smaller knives, but if I had to choose between the two sizes, I'd go with 10".

Eventually you'll find a use for most sizes of contact wheel. Profiling on a flat platen is for the birds and I wouldn't do it if paid triple. It's way too noisy, slow, and like you say, wears the platen fast. There's no need for it.

If you're looking for a method of setting the 10" wheel up for profiling get the book "How To Make Knives" by Barney and Loveless. It tells you how in the Loveless section.

Or you can just keep adjusting the work rest and slowly turning the wheel with belt on against your work(do this by hand) until the scratch pattern is in the center of the bar. It's doesn't take long.
 
I have lusted after a really large-wheel grinder ever since seeing the Victorinox grinders on "Knives, Swords, and Axes" on The History Channel. Those puppies must have had a 30" wheel or more. Yum.

Didn't Rob say the practical limit on a 72"-belted KMG is about 18"? A longer belt and extended tool arm would allow for a larger wheel. What's the next longer common belt size? 108"?
 
fitzo said:
.................

Didn't Rob say the practical limit on a 72"-belted KMG is about 18"? A longer belt and extended tool arm would allow for a larger wheel. What's the next longer common belt size? 108"?
Click to expand...


132" I believe, Mike. There's really a lot more of that size belt grinder out there than we realize.
Places like Koval sell an idler wheel setup that you can attach to the wall behind your grinder if you wish(remote mount).
Something like that would allow you great versatility in the type and size of contact wheel.
It would be limited only by the imagination. :eek:

I have a 14" that I've never used under the workbench gathering dust. I hope to use it in the spring or summer. To use it on my Burr King I have to use a 2" idler wheel from my vertical platen setup as the back wheel.

The magic number in inches to allow me to keep using 72" belts is 16". If I use a 10" contact, have to have a 6" idler, an 8" contact requires an 8" idler, etc., etc.

At least that's the way it is as it's set up now, I imagine if I took out a spacer bar on my idler I could get away with other combinations, but I don't wish to dedicate one of my grinders solely to large wheel at this time.
 
Mike -


- it won't slip, due to the large area of contact between back of the belt and the wheel
- you'd want to glue on a 2"-wide strip of neoprene rubber anyway, grind
will be more confortable
- at that price, I'd get 2 or 3. It does have rather weird bore size, you'd need to drill or bore it out, OR make a shaft that will match.
 
Mike Hull said:
This place will build the wheel for you, Mike. I'd get it with about 80 durometer rubber, hard, but not too hard. I'd get a solid wheel too(non serrated).

http://www.contactrubber.com/
Click to expand...

Ah, we's thinking alike, Mr. Hull! I was poking around over there before I posted the query about the belts. :D

Contact Rubber's only about twenty miles from me; I've passed by the factory many times. Might have to call them tomorrow just to satisfy me curiosity! Thanks!
 
Thanks rashid11.
On the subject of curved platens and platens in general, I have only used contact wheels, never a platen but I want to build one.
The platen is stationary though and the belt is moving pretty fast over it.

Obviously there has to be a heck of a lot of friction so the platen has got to wear down.

Of more concern is the fact that the belt will heat up too, will that not cause the join in the belt to let go?:eek:

Mike
 
Does anyone knows if I can use standart KMG work rest with 10" wheel?(on KMG grinder of course)

Thanks,
Alex
 
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