contact wheel questions.

BonhamBlades

Well-Known Member
What is the difference in poly vrs rubber contact wheels. I am just about ready to pull the trigger on my first 2x72 grinder. But I noticed that there is a considerable difference in price. If I buy the rubber wheel now it adds about $160 to the price but if I buy a poly and decide i would rather buy a rubber one it will cost much more than $160. So I am stuck and don't know what is the best choice, but iam betting all the dogs in the pound can help me make the right choice. thank you ahead of time...
 
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Jeff Conti

Well-Known Member
I have a rubber 8 inch wheel that I have used for 30 years. Rubber last longer. They might have a bit more traction on the belt depending on the hardness. I just built a NWG and added a 10 inch poly wheel. Cuts great. I don't know how long it will last but even if it's half as long as the rubber one, I'll be happy! Good luck
 

12345678910

Well-Known Member
I have a rubber 8 inch wheel that I have used for 30 years. Rubber last longer. They might have a bit more traction on the belt depending on the hardness. I just built a NWG and added a 10 inch poly wheel. Cuts great. I don't know how long it will last but even if it's half as long as the rubber one, I'll be happy! Good luck
Do you think that the wheel go harder over time?

I've got an old wheel too and I'm not sure it hardened as it aged, but I think it may have.
 

BossDog

KnifeDogs.com & USAknifemaker.com Owner
Staff member
we sell 20 to 1 poly over rubber. There is a big cost difference.

I've never heard of a rubber OR poly wearing out to failure. I'm sure it happens, I've just never heard of it. Both will wear and you may have to dress them to get them flat again. 2" wheels tend to wear down in the center of the wheel. I have seen a few failures of poly via overheating the hub and melting the tire from the hub. This has been where a mounting bolt was too tight on a bearing or a small wheel roller where it simply got too hot. I'd say this has been less than a dozen out of hundreds or more I've sold. You can definitely melt a poly wheel by touching really hot metal to it. Rubber takes higher temps and just kinda smokes and warns you that way to get the hot metal off it. Poly just melts into goo starting at around 180F to 200F degrees.
Poly wheels are good technology for the price. Rubber is going to last longer for sure. If you are going to be in the knife business for 20 to 40 years, get rubber. If you are going to be in the knife business 10 to 30 years, get poly. These are totally hypothetical life spans for both I made up just now.

A 70a duro hardness wheel in poly will perform exactly like a 70a duro rubber wheel.
 

Drew Riley

Well-Known Member
According to your poly idler wheel description, doesn't it say NOT to use for a contact wheel?

"This wheel is not meant to be used as a contact grinding wheel, just as a low cost idler wheel."
 

BossDog

KnifeDogs.com & USAknifemaker.com Owner
Staff member
According to your poly idler wheel description, doesn't it say NOT to use for a contact wheel?

"This wheel is not meant to be used as a contact grinding wheel, just as a low cost idler wheel."
that would be true of an aluminum idler wheel. Some copy must have been cut and paste over. I will have to find that and edit that out. In a 4 wheel set up, whether it is for a platen or slack arm, I always put on a couple different size poly wheels that double as idlers and contact wheels. The different sizes are so you have different radius to use.

Where did you see that at?
 

BossDog

KnifeDogs.com & USAknifemaker.com Owner
Staff member
that would be true of an aluminum idler wheel. Some copy must have been cut and paste over. I will have to find that and edit that out. In a 4 wheel set up, whether it is for a platen or slack arm, I always put on a couple different size poly wheels that double as idlers and contact wheels. The different sizes are so you have different radius to use.

Where did you see that at?
OK, found it. That was PVC wheel, not a poly wheel. The PVC wheels are not meant to be used as a contact wheel. They are simply a lower cost idler wheel option that Chris of Wilmont Grinders recently developed.
 

messermacher

Active Member
No one mentioned the Foam Wheels. Let me tell you; they are the bomb. I would recommend anyone that wants to make knives invest in a foam wheel. I bought the 8 & 10 Inch ones and they are better than sliced bread! Only 25 Duro and only use them on 220 - 1K. If you have the chance give one a try, you'll love'um.

If any of you can make it through MO, drop by and I'll show you how they work…….be advised, you'll go out and buy one.

John I.
 

rhinoknives

Well-Known Member
No one mentioned the Foam Wheels. Let me tell you; they are the bomb. I would recommend anyone that wants to make knives invest in a foam wheel. I bought the 8 & 10 Inch ones and they are better than sliced bread! Only 25 Duro and only use them on 220 - 1K. If you have the chance give one a try, you'll love'um.

If any of you can make it through MO, drop by and I'll show you how they work…….be advised, you'll go out and buy one.

John I.
John,
Foam wheels? Do you have a link to read about these?

Laurence

www.rhinoknives.com
 

messermacher

Active Member
Laurence the only thing I found was this and of course Burr King…http://www.contactrubber.com/detail.asp?c=382
I have Burr Kings in my shop so I bought mine from them…..they are spendy pushing $450 each but worth every cent. The greatest thing is the heat reduction in the finer grits. The foam gives when you apply pressure, doesn't build up the heat that other wheels do and allows a full hollow grind with the thin J weight belts that was created by the heaver/thicker X weight belts.

Trying to get a 3" one…..that would really be sweet.

Hope that helps.

John I.
 

cwilliams

Moderator
I can tell you from personal experience that both are great to a experienced knifemaker. Personally I would probably prefer Poly if it were just me in the knifeshop.
But recently a 5" poly wheel I found had really grooved up corners and sides of the poly. I found a in-experienced friend had attempted to do plunge work on my Blaze belt and had allowed the knife to contact the poly.
Never touch the poly with steel or it will abrade quickly. I had to replace that wheel as it was all but destroyed. I will probably try to reface the sides of the wheel and radius the corners later but that would not have happened with a rubber wheel.
Rubber resists grooving and tearing very well.
Hope this helps.
CW
 

BonhamBlades

Well-Known Member
Thank you for that insight willams. That is something I had not heard and could see that happening to me. I thank all of you for the help and have decided on rubber. Thank you again...
 
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