OD grinding books/lesson plans?

Always know where your diamond is in relation to the work centerline.

I'm not convinced there are any books that are "how to" regards precision grinding. I was fortunate to have been tutored by a person with many years of experience. From what I learned, I gather that it is one of the crafts that is more handed from one person to another, and is not a skill that everyone takes too. Some folks are just plain too ham handed to ever achieve the ability to be a decent precision grinder, nor do they become one with the machine. That's very important to achieve good results. In truth, technique is almost everything.

One of the things you must learn is to NOT tighten anything excessively, nor to *ever* lean on the table of the machine while it's working. Dressing the wheel dead on center is almost mandatory, especially if you're running the wheel head anything but at right angles. Knowing how to make wheel selections goes a long ways towards success, too. I trust you already know and understand about taking out taper, regardless of the nature of the grinding operation. You may already know how to make proper passes with the wheel, that one does not usually make passes left to right because it destroys the corner of the wheel and leaves a tapered section towards shoulders. Successful grinding of objects with a shoulder is usually accomplished by plunging the wheel, then traversing the table towards the tailstock. NEVER grind dry, especially on stainless, which is rather difficult to grind, anyway. There's simply way too much to try to absorb in a few sentences where grinding is concerned. With some luck, maybe one of your customers will take you under his/her wing and pass along some useful tips. The rest is up to you. Just like playing a musical instrument, practice makes perfect, but only perfect practice does. If you exercise poor habits, you'll get real good at applying them, and achieve a yield in keeping with the poor practice.

If I can answer any specific questions, I'd be pleased to try. I also may have forgotten more than you already know. It's been years since I last ran a precision grinder. Can't wait to fire up my Overbeck, though! Same size as your Covel, but with a drop down internal attachment. Do you have that accessory?

Harold

"Toolroom Grinding"--Norton Company--18th edition Copyright 1991.......170 pgs paperback.....

And NO you cant have mine--you will have to find your own!!!

Gunner, I'll let you in on one of the big grinding secrets of the ages; the taper correction formula which will make your grinding life easier.

To grind straight or to grind tapers on a universal table, take a test grind, measure both ends of the grind. Subtract the small diameter from the large diameter and divide that answer by the distance between measurements. Move the decimal place of that answer one place to the right (or multiply by

Ready for the example? You are grinding a straight shaft section 4 inches long, big dia after test grind is .756, small dia is .752, distance between measuring points is 3.5" (don't mic up to a shoulder for this test).

Move that universal table .0114 (out or in, depending on which end of the shaft you're trying to correct) on your indicator dial that is positioned

To grind tapers, you just compare your test measurements to the print measurements and correct for the difference.

There are no books, manuals or lesson plans that I am aware of that teach manual grinding techniques. All us grindermen round here were taught by an old grinderman 20+ years ago who was willing to hire us and show us what he knew. And now we're old, too - and a dying breed. If I can be of further service, email me off-list and I'll tell you more secrets . Darrell @ ICT

######################################## Gunner wrote: I know just enough about OD grinding to fill a thimble and have room for a small elephant. Ive managed to do some simple work to the proper tolerences, but Im still largely fumbling around. Ive a decent Covel

Anyone have any links/suggestions?

if the table pivot is worn, put two indicators 20 inches apart and take the difference... or the error in the shifting movement of the pivot will give you an erronious reading

the difference... or the error in the shifting movement of the pivot will give you an erronious reading

Very true. Most of the older machines are worn wherever there are contacting surfaces - its a harsh environment around grinders. A lot of grinders however may not have tables extending 20 inches both sides of the pivot (Do two 10's count?). Many I have used have 21 inches on the right but run only 15-16 inches to the left (YMMV). Anyway, that previously secret formula is meant to be used until you get the taper correct. On a production run of reamers with 2 tenths tolerance and back-taper, its worth the time.

Other handy hints: Warm up the machine well in the morning, bearings will grow. Leave it run during lunch. Never turn off the wheel head before spinning out all the coolant from the wheel. A wheel can store a lot of coolant in its pores which will settle to the bottom of a stopped wheel. When you start the wheel up again - whoa- major balance problem. Speaking of balance - static balance new wheels on the hub before mounting on the spindle. Don't forget the "ring" test. Never stand in front of a wheel when starting a grinder. That's the most dangerous moment in a wheel's life. (0 to 6000 in .01 sec) And remember what my old gaffer taught me: Safety glasses are for sissies; it takes a real man to face blindness.

HTH, Darrell

just figure the taper per inch and then get half of it on the difference of the two dial indicators..if the indicator are ten inches apart look for ten times the taper in an inch divided by two since you are going to take that off of both sides.... or you could run a dial up the piece for ten inches and set it to taper the amount your out in ten inches. Just make sure the indicator shaft perpendicular to it and in line with the wheel.