Surface grinder conversion contact wheel question

Chuck Gedraitis Knives

Chuck Gedraitis Knives

Joined
Dec 10, 1998
Messages
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So I am in the process of converting my surface grinder to run belts. I have been in contact with a few contact wheel companies looking for quotes. I talked to Stephen Bader this morning and mentioned that it would be unsafe to run a 1in wide belt on a 2in wide contact wheel. He mentioned that the belt could compress the wheel enough so that the edges of the wheel sat below the belt, thus wearing the wheel out on the edges. The belt would then not track properly.

I was just wondering what others thought about this? In the research I have done online I have seen quite a few pictures of guys running 1in wide belts on a 2in wide wheel.

I'm considering having a 1in wide wheel made to run 1in wide belts.
Thanks for any response,
Chuck
 
Chuck, the guys I know that have converted surface grinders, run 1" belts on 1" wheels and 2" belts on 2" wheels. I would not run 1" belts on a 2" wheel.
 
He is basically correct. Those wheels are fairly rubbery. If you are only going to run 1" could you crown the Wheel? What if you are trying to grind in a corner? You would be unable to do it.
 
I run a 1" belt, on a 2" wheel.

Because I wasn't smart enough to order a 1" wheel.

It's a 90 duro wheel, and there is no way I am going to compress the rubber enough to what Bader described.

There are many limits to this though, and I would most definitely not have planned it this way.

When I have time my wheel will get cut down to 1"

1" belts are significantly better for what we do, on a manual machine.

I might change my mind if I had an automatic machine, but I doubt it.

If you are in the building, and planning stage, get a 1", 90-100 duro, serrated wheel.

I am very happy with mine from Contact Rubber, couldn't ask for a better wheel.

You pay dearly for it, but it shows.
 
Fellhoelter said:
1" belts are significantly better for what we do, on a manual machine.
Click to expand...

Could you expand on this a bit more? I had always figured on going with a 2" wheel and 2" belts. Why have you found 1" wide belts work better?

-d
 
Sure, a big plus for me is that they are less work.
There's 1" less that I have to run off of the part.
At .050 - .100 cross feed , that is 10 - 20 less back and forths, PER PASS !
We aren't plunging straight down, full width on the blade, so that extra inch makes a big difference.
Even @ 1", we're double the width of a typical wheel.

The leading edge of the belt wears out relatively quickly, and it's different than a stone.
When a stone wears, it's just not flat anymore, it's still a stone, and still cuts.
Not so with a belt.
The belt will cut much less effectively on that leading edge, generating a lot of pressure.
This will result in higher temperatures, and more likelihood of tossing the part across the shop.
With a 1" wide belt, by the time this becomes an issue, you are ready for a new belt anyhow, so you swap it.
You are more likely to keep trying to push a 2" belt further
You could have 1" of worn belt, and 1" of relatively fresh abrasive.
If you split the belt, you have already swapped by that time, and all is well.

Meanwhile, you are still going back and forth because you are using a 1" wider belt, you'd be down to your next depth if the belt was 1"
So, it's faster, and more efficient.

I did 40 - 50 blades before I decided to try 1", and besides the time efficiency, I didn't get fewer blades per belt.
If I had, I might still consider running 2" belts.

A 1' wheel is easier to keep flat and true, and there is less belt splice/high spots to worry about.

And for the third time, because it's that important (if your trying to make money) a 1" belt is just way less work.

Let's take this little 1" high folder I am working on.
After heat treat, there are 3 depth passes that need to be taken off per side.
I rough the 1st 2 passes with a .100" Y increment per stroke.
Roughly 22 strokes to get a 1" belt off of it.
44 strokes for the 2 passes.
The finish feed is .050" per stroke, so 44 more just for the finish stoke.
That's 88 back and forths...

With a 2" belt, I need 34 strokes per roughing pass, and 64 for the finishing pass.
132 Strokes.

So, the 1" belt is only 67% of the work...

Any day you can speed up a process by 33% is a great day in my book.

There's more I am sure, but this is what I got off the top of my head.
 
So how many of you guys are running one inch belts I have never thought about it as I have always ran two inch belts
 
Man, reading threads like this makes me drool for a surface grinder!

Chuck, looking forward to pics.
 
was going to ask what the thoughts were on the gator belts as they seem liek a top choice for a setup like this
 
I didn't either Don.
It took a LOT of convincing.
Being a Tool and Die guy, it seems wrong to me.
Ken Onion convinced me to try after 2 years of him telling me over and over.
It was the fact that I was only out an evenings work that finally got me to try it.
I could have sold the wheel If I didn't like it.

It's hard to believe, and even harder if you have a lot of hours on a surface grinder like I do, but I can take .010" off per pass, with no heat generated.
I literally took 6 folder blades down .020" in 4 minutes last week.
And that was flipping the part, to take it off both sides, and swapping belts to take the final .002" per side off with a 320 grit belt
 
The Gators are great Butch, for finishing.
You can dress them like a stone.
I don't like them to actually remove much metal with though.
 
Fellhoelter said:
I didn't either Don.
It took a LOT of convincing.
Being a Tool and Die guy, it seems wrong to me.
Ken Onion convinced me to try after 2 years of him telling me over and over.
It was the fact that I was only out an evenings work that finally got me to try it.
I could have sold the wheel If I didn't like it.

It's hard to believe, and even harder if you have a lot of hours on a surface grinder like I do, but I can take .010" off per pass, with no heat generated.
I literally took 6 folder blades down .020" in 4 minutes last week.
And that was flipping the part, to take it off both sides, and swapping belts to take the final .002" per side off with a 320 grit belt
Click to expand...

Two of my best friends have belts on surface grinder, I have used them and it's works, but I still prefer the stone. I can take .010" off in one pass (with the right stone), but usually go .005". The only reason to run a belt (IMO), is you can get a finer finish with a belt. That said, I might change over one day.:)
 
Wow, I'm definitely interested in hearing about what stones give that Depth of Cut!

In the various shops I have worked in, and the few thousand hours I have cranking wheels on a surface grinder, I have never seen such rates!

I need some of those.
The best I have seen is probably .0025" on a very well fixtured part, and flood coolant.
 
Fellhoelter said:
Wow, I'm definitely interested in hearing about what stones give that Depth of Cut!

In the various shops I have worked in, and the few thousand hours I have cranking wheels on a surface grinder, I have never seen such rates!

I need some of those.
The best I have seen is probably .0025" on a very well fixtured part, and flood coolant.
Click to expand...

Norton, induced porosity, 46 grit, 1/2"x7", I don't have the number in front of me. .010" down and .030"+/- cross feed. Take .010-,020" off one side and flip and repeat, same comes off both sides, no coolant, no warp. Like I said, I usually take .005" at a pass, but can do .010". I have ground the steel for well over 600 folders doing it this way. Maybe I'm doin it wrong, but it works for me.;)
 
I would certainly say you aren't doing anything wrong!

I'm leaning more towards I wasted hundreds of hours in front of a grinder taking smaller bites.
I truly would appreciate a # if you think about it sometime when you are near the wheel.
That's a good wheel to have in the arsenal.

I'm guessing it's a soft wheel, are you having to dress it often?

They never would have convinced me to try a belt if I had ever seen results even remotely approaching yours.
 
Brian, the wheel is a Norton #32A46-GVBEP. It's fairly soft, G hardness. Have to dress it about every two or three knives. Get around 50-60 knives per wheel, mostly all damascus.

My grinder is an old Delta Rockwell 6x12 manual, with an import ceramic fine pole chuck. I had a hell of a time when I first got it, too much heat, warping and very slow going. I tried 5 or 6 wheels before I found this one. A guy at the Blade show years ago told me to get a Norton induced porosity wheel, said they cut fast and run very cool. I can grind all the parts for a folder in 15 minutes or less, sometimes taking .040"-.050" off. This from rough forgings (damascus bar stock). I don't thing a belt would be any quicker. ;)
 
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