ID grinding hard chrome.

[eKretz]

I believe the intention there is so that the facet that's worn on the diamond is angled toward the center of the tip. Then it can be rotated every now and then and kept at least somewhat pointed at the tip longer. I always made my diamond holders so they presented the body of the diamond at 15° (negative) to the wheel. But mostly had the tip on center of the wheel the best I could.

 

[Milling man]

As far as I know, tilting and/or offsetting the diamond from the center of the grinding wheel (offset in the direction of rotation of the wheel) is done for two purposes:
- uniform wear of the diamond pencil and the ability to turn it
- the impossibility of increasing the depth of cut due to the softness of the pencil

 

[eKretz]

I've only seen it recommended to put the diamond either on center or behind center. This prevents any deepening of the dress/cut due to varied pressure. Heavier pressure then pushes it out of the cut.

 

[john.k]

A lathe will never be suitable unless you can reliably infeed .00001" per traverse...........absolutely none of the principles of grinding are being applied here ......first being the wheel should spark out in three traverses when infeed is cut..........the grit must cut freely and not be jammed in to the work.

 

[EmGo]

As far as I know, tilting and/or offsetting the diamond from the center of the grinding wheel (offset in the direction of rotation of the wheel) is done for two purposes:
- uniform wear of the diamond pencil and the ability to turn it
- the impossibility of increasing the depth of cut due to the softness of the pencil

I'm not a physicist who has studied the diamond-grinding wheel interface, so I have no strongly-held position

But, on machines I have used, these companies have all placed the diamond exactly radial :

Heald
Landis
Norton
Cincinnati
Arter
Brown & Sharpe (#13, not surface grinders)
Hoagland
Reishauer
Hofler
Gleason (rebadged Okamoto and also their own)
Maag
National Broach
David Brown

so, since it's never been real important to me, I just follow-the-leadered. The only place I've seen the diamond off-center and angled has been on surface grinders. Maybe it serves a specific purpose there ?

 

[john.k]

Ive always angled the diamond for the reason given ,and always just a little below centre ,so if anything gives ,the point doesnt dig in.......I never use the tailstock holder,but a small portable on that bolts to the slot in the table.

 

[triumph406]

full strength Sunnen MB-30 honing oil actually worked the best but was a mess to deal with.

That MB-30 is fun stuff, old clothes, long length smock and gloves required for that stuff, can get a rank if old and well used.

 

[michiganbuck]

EG's post 225 is true, the B&S 13 and other grinders diamond holder is/was holding the diamond straight horizontally and is/was recommended to be set at the center of the wheel.
Also back in the day before my time diamonds were commonly removed and reset/rebrased to a fresh sharp facet. Placing the diamond at the center allows one to know exactly how much stock/height is taken from the wheel (Not exact when offset from the wheel center).
It would be interesting to know when the angled diamond to create a facet came into play/use. Likely this is not as good as resetting the diamond. I have used in-house brazed diamonds and had them go flying.
I like a diamond to be angled 15/20* in the go direction and be set exactly on the wheel center*
And to be set on the chuck at various places so as to not overuse someplace on the chuck..and I like a 3/8" or better diamond shank.... and be turned in the holder every couple of whiles.

 

[eKretz]

That MB-30 is fun stuff, old clothes, long length smock and gloves required for that stuff, can get a rank if old and well used.

Yeah, that stuff seems to leave an impervious stink. I have washed my hands multiple times with hardcore hand cleaner after honing and they STILL have a whiff of that oil.

 

[Terry Keeley]

Yeah, that stuff seems to leave an impervious stink. I have washed my hands multiple times with hardcore hand cleaner after honing and they STILL have a whiff of that oil.

Heavily sulfurized I think, like Moly Dee tapping fluid.

 

[triumph406]

Yeah, that stuff seems to leave an impervious stink. I have washed my hands multiple times with hardcore hand cleaner after honing and they STILL have a whiff of that oil.

The shop will smell of MB-30 for a day or two after I've honed some parts.

 

[triumph406]

Heavily sulfurized I think, like Moly Dee tapping fluid.

Whatever's in MB-30 it prevents it being sold in California.

I lucked out when I bought a second hone, the prevoius owner drained out about 8 gallons of MB-30 which I still use.

 

[CarbideBob]

If you are dressing a wheel on any angle and the diamond or stone is not on centerline you will not get a true angle, you will get a conic section and distorted angle.
Flat dressing and you can off by 2 inches on a 6 inch wheel and it still comes out flat.

 

[Milling man]

you will get a conic section

Hyperboloid But with a small shift, the error will be very small.