Cylindrical grinding

[mhh]

I'm sitting here drawing a cylindrical grinding accessory for my Astra AR5 grinder and before I can get much further I need to find out more about what speed range it need to run in? any guesses or pure knowledge? Come on guys I know that some of you are old machinists and know EVERYTHING! Hehe

 

[Maryak]

mhh,

The speed range will be determined by the diameter of the wheels you intend to use and also the type of grit and the type of bond these wheels will use.

Hope this helps

Best Regards
Bob

 

[mhh]

mhh,

The speed range will be determined by the diameter of the wheels you intend to use and also the type of grit and the type of bond these wheels will use.

Hope this helps

Best Regards
Bob

I had more or less figured that out, but thank you for making that totally clear for me, I suppose that diameter of the part to be ground and the hardness also have a lot to say?

 

[MachineTom]

My surface grinder is 3600 rpm at the wheel with a 7" wheels, thats 6300FPM, feed is 10-20 ft minute. In grinding its the DOC and Advance that make the finish. The work needs to move fast enough not to burn, slow enough to not overload/deflect the wheel. My experience is with a surface not a cylindrical grinder.

Having used a tool post grinder a couple times in my lathe, the greatest difference was the lack of power from the 1/17hp motor turning a 2" wheel. I recall an advance of .010 per rev, and a doc of .0002 lathe spindle rpm of 200. Just to give a good finish on a arbor shaft. You can't remove much metal with a TP grinder.

Here is what was used on the surface grinder on cast iron fro a very nice finish, not a mirror finish, 46A wheel, .025 advance. a DOC of .0003" and about 10 ft min travel

 

[mhh]

My surface grinder is 3600 rpm at the wheel with a 7" wheels, thats 6300FPM, feed is 10-20 ft minute. In grinding its the DOC and Advance that make the finish. The work needs to move fast enough not to burn, slow enough to not overload/deflect the wheel. My experience is with a surface not a cylindrical grinder.

Having used a tool post grinder a couple times in my lathe, the greatest difference was the lack of power from the 1/17hp motor turning a 2" wheel. I recall an advance of .010 per rev, and a doc of .0002 lathe spindle rpm of 200. Just to give a good finish on a arbor shaft. You can't remove much metal with a TP grinder.

Here is what was used on the surface grinder on cast iron fro a very nice finish, not a mirror finish, 46A wheel, .025 advance. a DOC of .0003" and about 10 ft min travel

That actually helped a lot. I have som charts with speeds and feeds for surface grinding and I think I can do the math and make it into something that can be used, at least for deciding what the speed range should be.

 

[Maryak]

I had more or less figured that out, but thank you for making that totally clear for me, I suppose that diameter of the part to be ground and the hardness also have a lot to say?

Some Guidelines for the above.

The work speed around 60-100sfm (surface feet per minute), e.g. 1" dia shaft 15 - 25 rpm.

The work traverse speed 1/8 - 1/2 the wheel width per work piece revolution, e.g. 1" wheel 2.5 ft - 10 ft per min.

The wheel infeed max 0.002" and much less when grinding to a shoulder or fillet/groove.

The above are for grinding with coolant.

If grinding dry, minimums are suggested for all parameters.

Also the work needs further support if the distance between centres is more than 4 - 6 x work diameter

Hope this helps

Best Regards
Bob