Surface Grinding

[John Hasler]

First off, let me reiterate that I know less about surface grinding than anyone.

ALMOST anyone

Steve

Second that. Won't stop me from suggesting that a multigroove belt might improve the finish even more, though.

[Conrad_R_Hoffman]

+1 on good link belts. They can cut vibration by a lot, which is also why the table saw people swear by them. You can do very nicely on CRS, especially with the 60 grit wheel. I've always wondered if my 5SG60 is a bit of a dud, but they're so expensive I'll never have another to compare it with. Balanced, it's great, but I'm guessing few people do that. Anyway, nice job with the T&C!

[Harold_V]

That looks like a mighty nice finish for CRS!

Especially considering the type of machine, and the fact that it is not three phase. It's hard to eliminate the pattern generated by pulsing single phase motors.

Of necessity, I've done some limited precision grinding on a similar machine. They're a far cry from a proper surface or cylindrical grinder, with surface finishes being one of the problems.

H

[GlennW]

Conrad,

I bought a 5SG60 wheel to try and it has hardly been off of the spindle since. It's my "go to" wheel for sure.

I mounted it on an adapter with balancing capability and balanced it using a Stuhr. I also use flood coolant, but I am curious as to what you are dressing yours with. Norton recommends a cluster type dressing tool, which is what I have been using with it.

If you are using a single point diamond, there there may be a remote possibility that it could effect the finish, although I really couldn't say why.

Just something to ponder.

[SteveM]

I bought a 5SG60 wheel to try and it has hardly been off of the spindle since. It's my "go to" wheel for sure.

Can you explain the mystical properties of the 5SG60 wheel?

Having grinding experience limited to bench grinders with 32A and 36A wheels, 5SG60 is foreign to me.

Steve

[GlennW]

BENEFITS
3-5 times more life than aluminum oxide wheels, for maximum productivity.
Double (2X) rough stock removal rate compared to conventional abrasives.
Less burn, less dressing; most consistent performing wheel.
Highest stock removal rates, maximum productivity, longest wheel life and lowest overall grinding costs.

APPLICATIONS
Surface grinding.
Tool and cutter grinding.
Drill sharpening.

FEATURES
High performance proprietary seeded gel ceramic aluminum oxide abrasive.
Self-sharpening abrasive.
High performance VS bond.
5SG is the most durable SG and aluminum oxide blend.

[Harold_V]

Interesting comments in regards to using a cluster diamond in lieu of a single point. In real life, the end result of a diamond dressed wheell is determined by a single diamond in a cluster, which would be the one nearest the centerline of the wheel. I expect the others limit how much that diamond will see as it dresses. Must like a high tooth in a shell or face mill. A single diamond should yield equal results, assuming lighter passes are taken. Sort of makes me think they're addressing the wheel's greater capacity to remove stock, which should be correspondingly hard on a diamond, albeit virtually impossible to measure.

H

[GlennW]

I'm thinking that it has more to do with the size of the diamond.

These wheels like an open face, and a larger diamond with greater surface area may crush the bond more and close it up, "dulling" the wheel.

The smaller diamonds in a cluster dressing tool would tend to "open" the wheel up more.

Possibly...I guess...

[earlgo]

I have used a single diamond dresser since 1985 or so. It peels off a minute amount of abrasive in a very shallow pass done fairly rapidly.
The 5sg wheel was recommended to me by a Norton Sales guy because I said I was going to be grinding hardened M2 tool steel. He said that this was the best wheel they had for that application.
When grinding, as mentioned earlier, I typically start on one edge and traverse x and then advance y for the next pass, instead of passing the entire wheel face over the work. It seems to be easier on the work in that it runs cooler and does not ripple as badly. I do not use any coolant but occasionally blow air from a squirrel cage fan across the work that is sucked into a shop vac. Mostly to get rid of swarf. ( The vac hose has had some holes melted in it from those yellow things that fly off.)
{Here I was going to have a pic of the "well used" diamond, but the Celestron Microscope finally died . Oh, well, it was C.R.A.P. anyway. I'll post a pic later if I can.}

--earlgo

[Conrad_R_Hoffman]

Hint, possibly mentioned before- since the wheels wear most on the edges, bring the center down to the diamond first and start dressing there. That will be the high spot and avoids surprises with an unexpectedly heavy cut.

I use a small single point dresser because that's what I've got. Seems to work OK with the 5SG too. My problem is strictly balance.

[Harold_V]

I'm thinking that it has more to do with the size of the diamond.

These wheels like an open face, and a larger diamond with greater surface area may crush the bond more and close it up, "dulling" the wheel.

The smaller diamonds in a cluster dressing tool would tend to "open" the wheel up more.

Possibly...I guess...

Your comment certainly has merit. A rounded diamond does a poor job of dressing, while a tiny diamond doesn't really get rounded---it most likely presents a sharp edge to a wheel until it is lost from the matrix. The typical holder restrains the diamond at an angle, so simply rotating the diamond will present a sharp edge. That's assuming one rotates the diamond.

I have a fairly large diamond in a holder, which I have used freehand. It is well rounded as a result. It certainly doesn't yield a wheel that cuts well.

H

[GlennW]

The typical holder restrains the diamond at an angle, so simply rotating the diamond will present a sharp edge. That's assuming one rotates the diamond.

The diamond on my OD grinder has a hexagonal area just below the diamond. I rotate it one flat every three wheel dressings or so just to present a sharp corner to the wheel. Being hexed reminds me to rotate it.