Choosing a grinding wheel

[peks]

We are looking at replacing a recip surface grinder. It is used to grind heat treated 1566 (~50 rc) and m2 (~60 rc) steels. currently we use an al oxide wheel that does very well on the 1566 but has a little trouble maintaining flatness on the m2.

Main decision: wheel type. CBN has been suggested by the wheel manufaturers but the machine manufacturers seem worried about it for the 1566 in recip. we use cbn to creep grind these same parts with no problem. other suggestions?

also, what would be the benefits of changing to creep feed? flatness of the thin section (0.050-0.150") is the most important, surface finish, not so much.

 

[saberblue]

While you are looking at the wheel make sure that you do not neglect the grinding fluid and how it is applied. While I would like to tell you that it is all fluid selection related and that my product was the only one that would work probably even more important in creep feed grinding tool steels is the fluid applicaion.
This link -

http://www.masterchemical.com/na_en/technical_information/tech_bulletins.php

will get you to a series of technical bulletins that may provide some help

 

[peks]

Thanks saberblue,
these look like a very useful primer on cooling and I will read as much as i can.

I think i will be limited to a water-based cooling system so i don't have to add a parts washer to the cell. (space constraints and cycle time)

should this narrow my available choices?

 

[saberblue]

There are a lot of variables in selecting a fluid -- in creep feed grinding of tool steels using cBN wheels the defalt would normally be a low foaming sulfurized soluble oil that you would run rather rich 7.5 to 15% volume volume % but depending on how you set the operation up and what trade offs you choose to make there are a variety of different options

glad to be of help

 

[peks]

any other suggestions on the grinding wheel or process selection? The ground surface is just a simple flat knife edge.

Current: vertical spindle, aluminum oxide ring wheel, recip,
water based coolant

benefits of changing to:

horizontal spindle? other than surface finish.

CBN? the cost is hard to justify, are there any other options out there?

creep feed? is speed the only reason to change?

 

[saberblue]

I don't think we have any where near enought time or information to try and discuss these issues in a productive manner.

The nuts and bolts of this kind of change require a lot of study and discussion. It is about selecting the best alternative for you in your specific situation - in the manufacturing world there is no one right answer but rathar a whole lot of answers that will all get you to the same place and it is your/our job as maufacturing engineers to select among them.

Attached is a web address

http://www.abrasivesmall.com/sal.htm

for one of the brightest grinding guys I know he may be able to help you objectivly look at the alternatives avalible to you