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Surface Finish? Diamond Cup Wheel, Carbide Roller, Monoset

JohnnyJohnsoninWI

Hot Rolled
Joined
Dec 9, 2003
Location
North Freedom, WI, USA
This job comes through my shop a couple times a year; reconditioning carbide guide rolls on a Monoset. I use a Norton ASD 120, type 11V9, 3 3/4" cup wheel at 8000 rpm. Work head is running about 80 rpm. Grinding one side of the "V" at a time.

The surface finishes always look like the pictures unless I really slow down the cross-feed on my finish pass to .0001 doc & feed .001" per rev. I can get a very nice surface finish but the finish pass takes as long or longer than it does to rough .010 off a side.

The wheel spindle was rebuilt 1-200 hundred hours ago by Sopko. Does this look like bad workhead bearings? Maybe it would be faster to polish with diamond lapping compound?
 

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Are you using the 1/16 or 1/8 face of the flair cup wheel and flipping the part 180* and then just come to the same zero for finding center? Running wet or dry? What machine? How does the finish actually feel running a ball point pen across? ASD is a hard bond so may not release dull diamonds, SD may stay sharper, D wheel even sharper than the SD..

You might try a dressed trued 1v1 wheel so having the diamond on an angled OD. Might put a mill jack under your work head to assure no vibration transferred. Hone or shape the work head foot/feet to be sure no side rocking possible, Might try 4000 rpm just to see if such high RPM(8K) has more motor or spindle vibration. I would run that wet perhaps build a box to catch coolant, be very sire the work head and motor belt is smooth at contact, have a line up mark on wheel mount and spindle so brake dress or green wheel dress remains good when/if replacing wheel and mount. keep wheel on its own mount with checked balance., dress wheel often with a green stick. Might indicate the flair cup wheel OD to male it run smoother. check head stock to have a little preload, Might rough at 8k and finish at 4k if a smoother grind is found. would use a Norton or other known name brand wheel. Running wet a 220 might be the choice.

Yes be sure you can get in with the wheel or an 11a2 might work.
Ref: https://www.nortonabrasives.com/sga...tonindustrial-7362-lr-bookmarked.pdf#page=295

Ot: how close are you getting to TIR id? would running between centers make a more solid set up? Is your screw washer smaller than your backing shoulder? I like to spin round my inside screw hex so a round bumps my washer.
 
MichiganBuck,

Thanks for your reply. I needed to return to my shop this morning so I could better answer some of your questions.
The machine is a Cincinnati Monoset and am grinding dry. This machine doesn't lend itself to wet grinding. I'm using the face of the cup wheel, not the side. The wheel I have has about .o8 width of abrasive.

I grind one side of the "V", flip part, then grind the other side. The included angle of the "V" is 75-degrees and there is a .015 radius at the bottom. This geometry really limits the wheel options.

I replaced the workhead motor with a DC motor and drive in order to reduce the rpm for another part I grind. For this part the controller is running over 50% so I don't think cogging is the issue, although I haven't ruled it out.

As far a finish shown in the pictures goes, although it is visible, I can't feel the finish with my fingers but I didn't try a ball point pen. My washer is the same size as the backing shoulder.

How do you true a cup wheel? For straight wheels, I use a brake controlled truing device. However, I haven't figured out the best way to true any other wheel shape.

Thanks again for your help and have a great day.
 
qt:[ I don't think cogging is the issue,] clogging was not my point but dulling diamonds because of being held too long in the bond and not releasing so causing much more pressure.

ASDs are about the hardest cup wheels. D wheels are the most free cutting but made for no hitting steel. SDs are more free cutting than ASDs.

ASDs are actually for bumping a little steel and that is why they are so hard.

You can dress a cup with: grinding some mild steel, grinding the cup with another diamond wheel or a green hard green wheel, hand dress with a cracker jack held at about a 30* to 45* angle.and with a break dresser but spinning the break dresser at start so the cup does not have to start it.

The pattern may just be cosmetic and not any problem.
is the Monoset the only grinder you have for this job? I might use a cici #2 or a B&S 13 grinder or the like..
 
What I meant by "cogging" is when a DC drive motor turns so slow that it starts to "cog", i.e. not turn smoothly.

The carbide rollers that I'm grinding are actually guide rolls for a canning factory. As the steel coils are unrolled and sheared into shorter lengths, theese rollers align the steel for the next operation. Miles and miles of steel run over these rollers and sometimes notches are worn into the bottom of the "V" groove and steel gets imbedded into the notch, which I have to grind out. I didn't know about the differences between D, SD, and ASD wheels but, from your description, it sounds like I'm using the correct wheel in this application.

What is a cracker jack? Sorry if that is a dumb question.

I do have a Victor T&C grinder which is a knock-off of a Cincinnati #2, and have thought about trying this job on that grinder. It is usually set up on a different job, so I gravitate toward the Monoset. Maybe, the next time these parts come in, I'll give it a try.

Thanks again for taking the time to help answer all my questions, I really appreciate it.
 
I would likely run that job on the Victor between centers on a shoulder and nut arbor, with a type 1v1 SD 180 to 220 wheel, wet.

The type 1v1 is like a straight (type 1) but has an angle on the OD. they can be dressed with a break dresser but like all diamond wheels it is best to give the dresser a bit of a aping getting it started , then come almost off but not all the way off.

Or part held on a knock into the work head stub and nut arbor.(not on a collet held arbor)with having a line up mark on the arbor and on the work head, and the holder hub ground in the work head..

Crackerjack mini. (no question is dumb)
Desmond - Grinding Wheel Dressers - Crackerjack Dressers

The Victor looks like a very nice machine.
On the Victor I would put on a strip of masking tape to cover the opening gap between the moving table and the base, as a dust shield a bit of oil or grease on the base so the tape does not stick there.
Likely pull the table and clean balls and ways then put on the tape strip.
 
Thanks for the link. I've seen them but never knew what they were called before.
Thanks, also, for the wheel and setup recommendation. I will try them.
I purchased the Victor new in 2003 and have sharpened tens of thousands of slitter blades on it over the last 16 years. I was just starting out back then and it paid for all the other machinery in my shop.
 
QT: [sharpened tens of thousands of slitter blades on it over the last 16 years.]
'I'm mostly retired but still sharpen 344s with my old Cinci #2. (also called 5009 or Dusenberys ) double bevel 3"
They run about $11 new (from NFG $4.80)and I sharpen then for $ 2,50 running abut a minuet each so run at right around $60 an hour for the job. Mostly just run them to keep my company name and as a favor because customer has have a finniky machine that needs a smaller radius new they run about .008 to ,010R , and I run about .004 to .007

I used to sharpen pinking blade for $12.00 each, forget now but running 3 or 4 an hour. Likely 4 at that price. ran them under a magnifying glass just so I would make a miss and have to go around again. Yes I had to OD circle grind them first.

One news paper knife was a split circular knife, so in two parts 16 or 18" in diameter razor sharp with no burr. it was tough to handle with cutting ones self. They manufacture the knife then grind a thin place and break it in two so the edge matches with not a gap, I made the arbor out of a car flywheel on a knock in taper.

Back in the day I had most of the Detroit area newspapers. my sharpening would out perform new slitters,that were 5" with a double bevel only on one side. some/many had .030 wear land and some over a i/8 inch. I forget tha scrap diameter perhaps take 3/16' of so. New two story presses came from Germany and the Germans ordered no sharpening. So making the same knife a throw-away. I would get a call from the Detroit News and they would say we need xx blades tomorrow or we shut down the presses. The Detroit Free Press would never get that close to running short.

I was also doing flat knives to 32" and some cutter and surface grinder work.

Oh, the 1v1 grinding wheel likely would cost 600 to $900 but would run the job faster, have better finish and last a good long time.
I would pull the victor table every two years for cleaning..
 








 
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