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information about grinding precedure 2
- Thread starter DsaG
- Start date
The subject is very complex. It is very difficult to give helpful information without knowing what you wish to do.
Try a Google search. For the work we do GE Superabrasives is very good. Abrasives magazine is good although I don’t understand much of it.
Tom
Try a Google search. For the work we do GE Superabrasives is very good. Abrasives magazine is good although I don’t understand much of it.
Tom
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- Thread starter
- #3
May be able to help on the cutters, but you need to be more specific. Do you have a particular problem?
Keith Durkee
Keith Durkee
Does your question bear any relationship to carbide & ceramic tipped saws?
We have some on our web site at
Try some of the tool catalogs. Right now I am working with good information from an NTK catalog.
However Durkee’s approach seem to be the most common and often the most productive.
tom
We have some on our web site at
Try some of the tool catalogs. Right now I am working with good information from an NTK catalog.
However Durkee’s approach seem to be the most common and often the most productive.
tom
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- #7
RamingtonStall
Mechanical
Regarding CENTERLESS GRINDING, You would still need to be more specific in your question. The best General Guide was a manual put out by Cincinnati Milacron 30+ years ago, called Principles of Centerless grinding. I believe that Krar and Oswald included most of the key points in their 1974 publication : "Grinding Technology".
What are you wanting to grind? Condition of part coming to the grinder? What do you want to achieve? How do you intend to inspect it? Roundness? Straightness? Cylindricity? Surface Finish? Tolerances? Production Rates?
What Statistical Qualification criteria do you intend to apply? Six Sigma = 80% of tolerance? 75%? 67%? And then there are the discussions about roundness which is actually only a 3 sigma concern since it can't be too round.
Form Grinding? Bar Grinding? Thru-feed? Infeed? End-Feed? Camfeed-Grinding? Other? Shoe-Type Centerless? (Milacron referred to this as Micro-Centric.)
What are you going to do to the parts after Centerless Grinding? Lap Grind? Lapping? SuperFinisher such as Supfina?
Steel Industry: Long Bars?
Bearing Industry: Rollers? Races? Thrufeeding Tapered Rollers?
Automotive: Input & Output Shafts? Torsion bars? Steering shafts? Piston Pins? Valve Stems? U-Joint Crosses?
Bowling Balls? Billiard Balls?
Fuel Injector Needles? Guitar Strings? Fishing Rods?
Medical industry: Hypodermic Needles? Bone Screws?
Structural Ceramics?
Air Conditioner Compressor Shafts?
Shafts for Tape Players or cassettes? Copiers? Cameras?
Cutting Tools? Twist Drills? EndMills? Punches?
Hydraulic Parts? Etc., etc. etc.
Probably the most important thing is that Centerless Grinding Machines are high production beasts. They can produce a lot of parts very quickly. They are frequently best used as a GAGE. i.e. Grind at a slower rate but achieve 100% duplicate parts so as to eliminate the need for inspection or for such things as parts segregators or "Select fit" assembly.
Have a nice day!
RamS
SAT SuperAbrasive Techniques, Inc.
What are you wanting to grind? Condition of part coming to the grinder? What do you want to achieve? How do you intend to inspect it? Roundness? Straightness? Cylindricity? Surface Finish? Tolerances? Production Rates?
What Statistical Qualification criteria do you intend to apply? Six Sigma = 80% of tolerance? 75%? 67%? And then there are the discussions about roundness which is actually only a 3 sigma concern since it can't be too round.
Form Grinding? Bar Grinding? Thru-feed? Infeed? End-Feed? Camfeed-Grinding? Other? Shoe-Type Centerless? (Milacron referred to this as Micro-Centric.)
What are you going to do to the parts after Centerless Grinding? Lap Grind? Lapping? SuperFinisher such as Supfina?
Steel Industry: Long Bars?
Bearing Industry: Rollers? Races? Thrufeeding Tapered Rollers?
Automotive: Input & Output Shafts? Torsion bars? Steering shafts? Piston Pins? Valve Stems? U-Joint Crosses?
Bowling Balls? Billiard Balls?
Fuel Injector Needles? Guitar Strings? Fishing Rods?
Medical industry: Hypodermic Needles? Bone Screws?
Structural Ceramics?
Air Conditioner Compressor Shafts?
Shafts for Tape Players or cassettes? Copiers? Cameras?
Cutting Tools? Twist Drills? EndMills? Punches?
Hydraulic Parts? Etc., etc. etc.
Probably the most important thing is that Centerless Grinding Machines are high production beasts. They can produce a lot of parts very quickly. They are frequently best used as a GAGE. i.e. Grind at a slower rate but achieve 100% duplicate parts so as to eliminate the need for inspection or for such things as parts segregators or "Select fit" assembly.
Have a nice day!
RamS
SAT SuperAbrasive Techniques, Inc.
DsaG,
Best place to start in my opinion, Norton 3 part video on centerless grinder. It gives all the fundamentals on c'less grinding. you can then take it from there. They also have a nice book but its not as easy as the video. I found it hard to get Cinn's book as pointed by RamS but could be good. Also, try writing to St. Gobain's R&D unit - Higgins Research Center.
kgt74.
Best place to start in my opinion, Norton 3 part video on centerless grinder. It gives all the fundamentals on c'less grinding. you can then take it from there. They also have a nice book but its not as easy as the video. I found it hard to get Cinn's book as pointed by RamS but could be good. Also, try writing to St. Gobain's R&D unit - Higgins Research Center.
kgt74.
statorwinder
Automotive
Machinery's Handbook features some good points on most any kind of grinding.This book has been around since the early 1900's & is probably in its 30th edition.Most all machine shops will have a copy of this book.Local library may have a copy. mine is the 16th addition printed in 1962.
- Thread starter
- #10
prabharamani
Mechanical
We are facing burn mark problem in centerless grinding machine.We are using roller type dresser.The coolant flow is 80 lpm.Grinding wheel drive power is 22kw.The speed,feed is at recommended levels.Do we need to increase coolant flow?Pls do give any info on this subject
RamingtonStall
Mechanical
Regarding your question: <<"We are facing burn mark problem in centerless grinding machine.We are using roller type dresser.The coolant flow is 80 lpm.Grinding wheel drive power is 22kw.The speed,feed is at recommended levels.Do we need to increase coolant flow?Pls do give any info on this subject">>
Tell me more about the "Roller Type Dresser" Size, Type, Size and number of diamonds, etc. How is it driven? Depth of cut? Traverse rate?
What kind of finish are you trying to achieve? Workpiece material? Stock removal, etc.
============================================
Now, having noted that I would need more info, I will venture an answer anyway: Check the width of your diamond roll. Too wide and not enough pressure to actually cut or "True" the wheel and you will be riding on the wheel generating flat polished crystals, especially if your wheel is CBN. Check the Diamonds in the Roller to make sure that they are not too large and that they do not have large FLATS which will polish the crystal of the wheel rather than cutting.
Then, are you using a Dead Pass of a "Spark Out" Pass with the truing operation? Stop doing it. No spark out pass. How'd that work?
Then, if you are still getting burning check the infeed and the traverse rate.
Regarding Coolant, what type of coolant is it that you are using? Is it COOL, CLEAN COOLANT? IF it is not COOL, try adding a larger coolant tank or a Chiller. IF it is getting warm, then you do not have a large enough tank or you will need to add a chiller.
Let me know how it turns out.
RamS RamS@Free-Market.net
SAT SuperAbrasive Techniques, Inc.
Tell me more about the "Roller Type Dresser" Size, Type, Size and number of diamonds, etc. How is it driven? Depth of cut? Traverse rate?
What kind of finish are you trying to achieve? Workpiece material? Stock removal, etc.
============================================
Now, having noted that I would need more info, I will venture an answer anyway: Check the width of your diamond roll. Too wide and not enough pressure to actually cut or "True" the wheel and you will be riding on the wheel generating flat polished crystals, especially if your wheel is CBN. Check the Diamonds in the Roller to make sure that they are not too large and that they do not have large FLATS which will polish the crystal of the wheel rather than cutting.
Then, are you using a Dead Pass of a "Spark Out" Pass with the truing operation? Stop doing it. No spark out pass. How'd that work?
Then, if you are still getting burning check the infeed and the traverse rate.
Regarding Coolant, what type of coolant is it that you are using? Is it COOL, CLEAN COOLANT? IF it is not COOL, try adding a larger coolant tank or a Chiller. IF it is getting warm, then you do not have a large enough tank or you will need to add a chiller.
Let me know how it turns out.
RamS RamS@Free-Market.net
SAT SuperAbrasive Techniques, Inc.
prabharamani,
I think that you can increase the work speed to reduce the burn marks and also check the type and grit size of your grinding wheel. Usualy roll dressing in centerless grinding trends to close the wheels structure and make the grits to flat. As a result, too hot is generated and burn marks appear. The collant flow its enought, I'm working with 50lpm with no problem.
biffi
I think that you can increase the work speed to reduce the burn marks and also check the type and grit size of your grinding wheel. Usualy roll dressing in centerless grinding trends to close the wheels structure and make the grits to flat. As a result, too hot is generated and burn marks appear. The collant flow its enought, I'm working with 50lpm with no problem.
biffi
SF10Polisher
Materials
I Grind and Polish many different materials, for example,
SF10 Glass
I first start with a flat, clean non-grooved cast iron lap 8inches or so. I first grind the crystal with 20T micron Alumina grit, then 9T Alumina. W14 grit just before polishing which is about 2 or less micron size.
SF10 Glass
I first start with a flat, clean non-grooved cast iron lap 8inches or so. I first grind the crystal with 20T micron Alumina grit, then 9T Alumina. W14 grit just before polishing which is about 2 or less micron size.
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