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Newb getting started with grinding

ygolohcysp

Plastic
Joined
Mar 12, 2017
Hello,

A while back, I posted a few questions about grinding. The company I work for is bringing work in house, and we will be starting to do grinding on cutters that will get stacked onto shafts. Based on that thread, I came to the conclusion that a blanchard grinder would be best. The company purchased two used surface grinders. LOL Then they purchased 2 old blanchard grinders.

Anyway, we just received the first of the two surface grinders. A Chevalier FSG 1224 AD.

I did get the electrical and operation/maintenance manuals with the machine.

I've been put in charge of this grinding project due to my experience running manual mills and lathes, but I'm the closest we have to a machinist.

I understand that grinders are a whole other animal, and I know I'll get there. I can read the manual and get familiar with the controls that way. I'm really good at learning by reading and observational while doing, but I still have newb grinding questions.

1. For a hardened tool steel around 45 Rockwell, what is a typical amount for depth of cut? (my initial guess is .0005")
2. What about stepover?
3. What is sparkout? (The old Chevalier manual looks like it was translated to English, possibly from Canadian French).
4. Is there a best method for balancing new wheels?
5. Ring test, does any wooden hammer work?
6. This machine is setup for coolant with the cooler/filter portion next to the machine. Any suggestions on coolant type?
7. Adjustable force electric magnet chuck. How do I judge how strong to make that? Is the only down side to a stronger setting the deflection of the material I'm wanting to grind being pulled flat by magnetic force, and then being warped when I release the magnet?
8. Other than a grinding wheel being defective and breaking/exploding, and running the wheel into a part that's too tall in a direction that would force the part under the wheel causing it to break, flinging parts off the chuck, and eye hazards, are there any huge safety considerations that aren't obvious?

I realize these questions prove my inexperience, but I'm trying to learn as quickly as I can at this point.

Thank you for any info or tips!
 
Hello,

A while back, I posted a few questions about grinding. The company I work for is bringing work in house, and we will be starting to do grinding on cutters that will get stacked onto shafts. Based on that thread, I came to the conclusion that a blanchard grinder would be best. The company purchased two used surface grinders. LOL Then they purchased 2 old blanchard grinders.

Anyway, we just received the first of the two surface grinders. A Chevalier FSG 1224 AD.

I did get the electrical and operation/maintenance manuals with the machine.

I've been put in charge of this grinding project due to my experience running manual mills and lathes, but I'm the closest we have to a machinist.

I understand that grinders are a whole other animal, and I know I'll get there. I can read the manual and get familiar with the controls that way. I'm really good at learning by reading and observational while doing, but I still have newb grinding questions.

1. For a hardened tool steel around 45 Rockwell, what is a typical amount for depth of cut? (my initial guess is .0005")
I would rough grind with coolant on about .001-.002" doc. Set the stepover to about 1/8-1/4" and see how it sounds. Alot will depend on the wheel hardness (start with 46 for general purpose) and the type of bond. You should be able to hear if it is not grinding good and make adjustments from there. Finishing (after a fresh wheel dress) would be around .0002-.0005 doc, depending what your surface finish requirements are.

2. What about stepover? ^

3. What is sparkout? (The old Chevalier manual looks like it was translated to English, possibly from Canadian French).
It means letting the wheel go over your part until no more, or very very faint sparks are left.

4. Is there a best method for balancing new wheels?
Honestly, I've never needed to balance one, but you basically buy a balancing fixture and adjust lead weights on the wheel hub. It will look something like this https://www.mscdirect.com/product/details/02220960

5. Ring test, does any wooden hammer work?
Should (but not sure)?

6. This machine is setup for coolant with the cooler/filter portion next to the machine. Any suggestions on coolant type?
Any brand you would like to try, but it needs to be grinding coolant (not 'regular' coolant).

7. Adjustable force electric magnet chuck. How do I judge how strong to make that? Is the only down side to a stronger setting the deflection of the material I'm wanting to grind being pulled flat by magnetic force, and then being warped when I release the magnet?
Usually it will be set to max, with the exception when you are trying to get thin pieces flat. In that case, I usually slowly dial it up until I can move the part by hand, but not too easy, will take some practice to get a feel for it.

8. Other than a grinding wheel being defective and breaking/exploding, and running the wheel into a part that's too tall in a direction that would force the part under the wheel causing it to break, flinging parts off the chuck, and eye hazards, are there any huge safety considerations that aren't obvious?
You pretty much have it covered ^. Be warned though, if you blow up a 12 or 18" wheel it can be very very serious, so err to the side of caution!

I realize these questions prove my inexperience, but I'm trying to learn as quickly as I can at this point.

Thank you for any info or tips!

more letters here... ;)

edit: For #7, if you need to do any of that type work, 2 tips...

1) You cannot use the same stepover/doc as 'regular' grinding. Think more like finish grinding.
2) A piece of paper between the chuck and workpiece, along with a variable mag, will do wonders for getting something flat.
 
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Spark out is running a pass with no depth feed, like a spring pass on a mill. It proves the dimension. Because of imperfections of balance and roundness of the wheel you should get random tiny sparks all across the work. If you don't it means the work swelled with heat during your last grinding pass and has shrunk undersized as it cooled.

I build injection molds and normally grind the small bits dry so I am very sensitive to controlling heat in the work. I also use a very agressive wheel, a Norton SG5, 46 grit in the G hardness. With this I find I can take .003 to .005 per pass with a .025 step over for roughing but this wheel is too soft to hold a corner.

While I imagine you have an automatic feed, I would suggest grinding some parts manually for practice. You need to learn the feel, the sound, and what the sparks look like, both when things are going good, and not so good. Then you'll have a better idea how things are going when running auto.

A member here, Michiganbuck, has a useful suggestion; only feed on the "push" stroke, when the wheel is pushing into the work as in conventional cutting. That makes the return strokes, which would be climb cutting, a spark out stroke. This adds some cooling time but more importantly, gives a visual indication how hot the work is getting. This return stroke will throw more sparks than a sparkout, but less than a stroke where the cross feed was advanced. If it starts throwing sparks like it's grinding, it means the work is swelling from heat, which means time to slow down or decrease the cross feed. It's all too easy to be happily grinding back and forth, advancing the cross feed each time, and all of a sudden get big angry orange stripes of sparks, which mean you've just ground a big gouge in your work.

Additional safety tip... we all wipe the chuck with our hand to make sure it's clean when placing work. Use your hand not a rag. A rag can get wrapped on the wheel and pull your hand in. Likewise, don't try to wipe under the wheel if there is not enough clearance for your hand. The results will not be good.

Dennis
 
....
Additional safety tip... we all wipe the chuck with our hand to make sure it's clean when placing work. Use your hand not a rag. A rag can get wrapped on the wheel and pull your hand in. Likewise, don't try to wipe under the wheel if there is not enough clearance for your hand. The results will not be good.
Dennis
Results not good is an understatement.
If anywhere near close do not do this unless you'd like to see the inner workings of your knuckles and fingers.
Kind of interesting at first as there is a big wack but no pain at first. You can look at it and go "Well ,that's not right..Neato, look how that moves inside there as I bend my fingers".
Grinding wheels bite and then suck your fingers, stick, hand diamond in with no warning.
(okay, safety mode off, we all know be safe...wear glasses, no touchee the rotating mass,, blah, blah)

Blanchard grinders are totally different than surface grinders in wheels and use. It is all chuck speed and downfeed rate.
Blanchards always need a spark out where you stop at size and let in continue to run for a few minutes.
Some jobs this may be 1-2 minutes some stuff I run gets 15 minutes of sitting there going round and round and round and round to get flatness and surface finish.
Also when moved a Blanchard will very often (always?) need it's head aligned to make flat parts. Regular surface grinders don't care about this much.

Can you somehow find an old retired grinder hand on craigslist or such to come in and give some help and hints?
This will be hard to master on your own or U-stuff videos.
Making it work and being productive two very different things.

A FSG 12x24 will run a good sized wheel even if at only 1750, I'd consider balancing if finish a care.
We are all here to help but details, details, and the devil within. ........Welcome to the rabbit hole, many of us down here.
Bob
 
The very first thing:
Likely a new to grinding person should start with an instructor and a bench grinder. First note the wheel turns in a certain direction and so will tend to push the part that way. A little pressure pushes a little and a lot of pressure may push the part so hard you can’t hold it. With such excessive pressure the wheel will tend to push it down or flip it from the way you intend to hold it.

Notice that if the grinding wheel is running true to center with being nice and round and smooth the touching of the part starts grinding smoothly and so it is easy to start the grinding and you can control pressure. If the wheel is not round and true to center it will seem to bounce on the part trying to knock the part from your holding, give a poor finish, knock it downward, pull it from your hand or knock your hand to another position, perhaps grinding your hand or breaking the wheel..

Notice that any of these adverse conditions can grind your fingers or hand and also can cause the wheel to burst and explode. Most all grinders from bench to surface grinders, OD and ID to Blanchard’s are the same. The grinding pressure, direction of force on the part, trueness of the wheel, how well the part is held are basic factors.

Additional factors are the wheel RPM being correct, the wheel being examined before use, being installed correctly, the kind of wheel being for that piacular part material and having the proper grit size and hardness.

Being competent on the bench grinder includes, knowing safety rule of wear safety glasses, no rings , gloves, long hair. Know to look at the label to see the wheel RPM and wheel RPM are suited. Know to inspect wheel mount flanges. Know to ring test the wheel. How to properly tighten. How to assure it will run smooth and round by dressing. Know how the wheel direction will push the part when the part touches the wheel. That a bench grinder the common rule is to have the rest table so close to the wheel that it can not catch your finger between. this space is usually 1/16 or less. To not grind on the wheel side and be sure all guards are properly in place.

OH! I almost forgot heat..on the bech grinder heat can burn your hand and so lose the part, on many grinders heat can swell/grow larger the part and so cause all kinds of problems.

One should fully understand these things on the bench grinder before attempting to run another type of grinding machine.

Know on the surface grinder if you can topple the part with three fingers it may come loose from the magnetc holding. Good to block-in and/or clamp a chancy set-up, Know how to wheel feel the part so you don't wreck into a high place.

Good to watch Bob Bailey on you tube...but know he is a seasoned grinder hand so it will take you a time to be that comfortsable around the grinder.
 
A couple things... Yes, like Bob said (I think) be very careful with your fingers when wiping off a mag chuck. Worked with a guy who did that carelessly and now has 3& 1/2 fingers. :ack2: I've also done this, but much more fortunate, just 3 stitches on my pinky finger... and let me tell you, it happens in the blink of an eye! :eek:

Blanchard grinding is definitely a different animal as stated. You would be wise to pay someone to teach you some things. The blanchard I ran had a 30hp (maybe 50hp?) motor on it. It did not stop for anything or anyone... don't want to be on the wrong side of that.
 
Safety should be first considered before operating any machine. For grinding, certain basic rules are listed in OSHA and other publications, it is good to read this material and seek advice if any rule is not clearly understood. The most basic safety rules are to wear safety glasses, ring test every wheel, compare on -the-wheel-blotter listed wheel speed to spindle speed, always use blotters to mount wheels on smooth and burr free wheel mounts. See that the spindle rotation is in the direction that tightens the wheel nut, I would add to dress any newly mounted wheel before leaving it so you or the next operator will not start with a rough running wheel. Be sure the wheel will clear the work with not crashing into a high place or fixture, be sure the part is secure. Know all the machine operating controls and that no travel is engaged at the starting. I like to also add: park the machine with much clearance away from the part if any measuring is needed or hands in the set-up is needed and try to never have the part so set that a pinch point that the wheel might catch a hand or finger, don’t finger touch the wheel but know and think about the direction the wheel would slide off your finger or catch and flip it. a pencil, a small Allen wrench or most any small object might be touched to the wheel in the roll-off direction to feel that the wheel is smooth, yes with being sure that object is well clear of pinching or touching anything. I currently I wear a dust mask when grinding even thought I have served many years not wearing a mask. Note that some grinding requires wearing ear plugs. Oh, and the/any machine needs to be properly grounded. The ground prong needs to be on every motor or machine wire and it doesent hurt to have an extra ground wire on a machine. OSHA requires that the wheel spindle RPM be listed where the operator can see it. Be sure your work space/area is clear of anything you might trip over while working or exiting. I feel that it is not good for the work part or your safety to talk to someone while grinding, most often surface grinding needs full attention. In the event of noticing any power failure feed the wheel away from the part.
Best/good to leave electrical work to the trained electrician, but every person running machines should know Black on Gold(brass) and White on Silver is the rule for wall outlet plugs and switches/don't touch it when in any doubt.
*Watch and listen for any changes in sparks or sound while grinding as that may indicate a problem, Stop grinding and find the reason.
*know for sure that your wheel will not crash/bump a high place on the work part.
 
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Safety should be first considered before operating any machine. For grinding, certain basic rules are listed in OSHA and other publications, it is good to read this material and seek advice if any rule is not clearly understood. The most basic safety rules are to wear safety glasses, ring test every wheel, compare on -the-wheel-blotter listed wheel speed to spindle speed, always use blotters to mount wheels on smooth and burr free wheel mounts. See that the spindle rotation is in the direction that tightens the wheel nut, I would add to dress any newly mounted wheel before leaving it so you or the next operator will not start with a rough running wheel. Be sure the wheel will clear the work with not crashing into a high place or fixture, be sure the part is secure. Know all the machine operating controls and that no travel is engaged at the starting. I like to also add: park the machine with much clearance away from the part if any measuring is needed or hands in the set-up is needed and try to never have the part so set that a pinch point that the wheel might catch a hand or finger, don’t finger touch the wheel but know and think about the direction the wheel would slide off your finger or catch and flip it. a pencil, a small Allen wrench or most any small object might be touched to the wheel in the roll-off direction to feel that the wheel is smooth, yes with being sure that object is well clear of pinching or touching anything. I currently I wear a dust mask when grinding even thought I have served many years not wearing a mask. Note that some grinding requires wearing ear plugs. Oh, and the/any machine needs to be properly grounded. The ground prong needs to be on every motor or machine wire and it dissent hurt to have an extra ground wire on a machine. OSHA requires that the wheel spindle RPM be listed where the operator can see it. Be sure your work space/area is clear of anything you might trip over while working or exiting. I feel that it is not good for the work part or your safety to talk to someone while grinding, most often surface grinding needs full attention. In the event of noticing any power failure feed the wheel away from the part.
Best/good to leave electrical work to the trained electrician, but every person running machines should know Black on Gold(brass) and White on Silver is the rule for wall outlet plugs and switches/don't touch it when in any doubt.
*Watch and listen for any changes in sparks or sound while grinding as that may indicate a problem, Stop grinding and find the reason.
*know for sure that your wheel will not crash/bump a high place on the work part.
 
Good advice from the usual suspects in the above posts. Answers/advice to some of the OP's questions are solidly dependent upon the application and intended outcome.

DOC- Rough stock removal on hardened steel when heat warping wasn't a factor? I've used .007-.010 to rip through. When warping (thinner cross section) was a factor I only used .001-.003 for rough pass. Finish pass DOC? From .0001-.0005. Big difference that's largely conditional per the expected result.

For someone new to grinding I'd really suggest keeping a small notebook with recorded entries of ALL info for each session to compile a knowledge base. When no experience is available this may be all you have to help guide.

Coolant- Too many new products for me to suggest one. Been out of grinding duties for 15 years, only grind dry and at home shop.

Safety hazards that may not be obvious for the SG? One not mentioned is how little force is needed to move the table (longest travel, no graduations). While wiping down the chuck, checking dimensions, loading workpiece, etc. the table can move so easily you can be near the wheel before you realize it. Chances for the wheel contacting flesh or something else are very high. For safety I always move the table as far from work (to the right of the wheel for CW spindle rotation) as possible and LOCK the travel (if there is a lock) whenever I have to put a hand/finger/instrument in the grinding zone. When in a hurry or focused on taking a measurement I've been surprised several times how quickly the table drifted back too close to the wheel.

Blanchard? I haven't run one since 1985 and don't recall enough to offer advice.

General safety advice? If I'm grinding on residual mag I'll often use a magic marker (Sharpie) on the chuck to make a few arrows next to the work piece to tell me if it's moved even slightly. I watch the sparks and listen to the grind for changes but sometimes the change in sound or spark stream means it's already too late. The marker arrows can show slight movement before trouble happens. Plan/rehearse getting the wheel UP/OFF the workpiece and know where the E-Stop is before you start the machine, emergencies tend to cloud the mind. Good luck.
 
grinding parts that get stacked on a shaft generally requires paralism

much easier to get on eaven on a beat to death heald rotary sg or similar

some tool steel dosnt mag well

doable on a reciprocating chevilair with a flat chuck but likely a steep

learning curve
 
+1 to just about everything that's been said on here.
Grinding is an art, not science, it would be good if you had someone to watch and learn from, but even then, you'll have to feel your way through a lot of it yourself. I agree than a 6x18 manual would be better to learn the feel on. Your Chevalier is not fun to use manually, springy handwheels.
I had about a month of learning from an old hand, then was kicked out on my own to be dang near the only grinder in our shop. I run a FSG 818 like your 1224 alot. I like a 46 grit radiac (can't remember the hardness) for general purpose. You can do so much with it. But, I do not have much luck pushing the crossfeed more than .025. I tend to leave it around .015 because the pot' that controls it is finicky. I frequently take up to .010 depth of cut (on parts with lots of base) on this machine for rough passes, then redress, take .001 with the front edge of the wheel, then .0002 back the other way and get very satisfactory finish and flatness.

EVERYTHING matters in grinding. In no specific order: material, hardness, wheel diameter, wheel structure, wheel hardness, dressing speed, dressing diamond sharpness, depth of cut, longitudinal speed, crossfeed step. And here's the really fun part: no one answer is good for every situation. New, large diameter wheels cut better, but smaller diameter wheels will leave an inherently better finish. I use them down to the paper.

As mentioned, unless the part is thin and flatness is paramount, crank that mag power to 10. Be wary of very tall parts without a lot of surface area on the mag, I've knocked over or scooted or rung and ruined more tall parts, than I have thrown off the chuck I think. I also step the crossfeed both ways, so you're cutting conventional and climbing. As long as you've got plenty of part touching the magnet.

I double second the motion to wipe the mag with your hand, and never ever have a rag near a spinning grinding wheel.

Take all the advice you can, but put it to the test. PM me anytime, I run a nearly identical machine, and would be happy to help anyway I can. Get out there and make some sparks!
 
A Blanchard will run a whole bunch of cutters that will get stacked on a shaft very flat, but possible the head will need tramed to make dead flat and maybe the table be ground . Surface grinders can grind flat as well but need a flat chuck, decent machine, proper wheel, grinding ability.
Shop might do well to hire a retired grinder hand..

Need a retired ginder hand to come show us the basics.. Some blanchard and surface grinder helpful..20 to 40 hours a week.
$20.00 +- an hour depending on how helpful.

Likely would have been better to have done that before buying any machines.

*You might do a better job of telling exactly what are the parts and what you wish to do.
RE: [do grinding on cutters that will get stacked onto shafts.] doesent tell very much.
Grinding the teeth of cutters is another subject...likely not Blanchard or surface grinder work.
 
Just one more safety tip. It is possible to explode a wheel when you are approaching first touchoff, if you screw up and jam the wheel into the workpiece. I know, because I did it in a machining class once. Fortunately for me none of the wheel fragments hit me. Scared the beejezus out of me though.
 
Just wanted to say thanks for all the responses. We ended up with the Chevalier, and an Okamoto 1224 AD. The Okamoto was easiest to get working. Oddest thing was the motor for the coolant conveyor to advance the filter material was wired backwards compared to every other motor on the system, including the pump for the coolant. Might be why there was no filter paper with it.

I have done the ring test and dressed the wheel, worked with some scrap from the same material as the cutters we're grinding. I've gotten some pretty decent results so far. One of the responses here was correct, aside from final dimension that's + or - .0005, parallelism is the next most important thing for this.

The Chevalier, well, I really don't like it as much, though I have gotten a better surface finish with it. I think it has more to do with the wheel itself.

So far, we've stuck to a max of about .0012 for auto advancing on the depth (Z for my mind having worked on bridgeports, and I think Okamoto as well, but the Chevalier calls that Y I believe).

At some point after we get these done and this system out the door, I'll be figuring out the 2 Blanchard grinders. Definitely going to work on the small one first. I think we're going to have to upgrade the building electrical service to 480 from 240 first. The Chevalier is currently running on step up transformer putting out 578 volts because it's still setup for 575. I think we're gonna get rid of that one and maybe get a larger surface grinder to go with the Okamoto.
 
Okamoto makes a nice grinder. As a former toolmaker for the American machine tool industry it hurts a little to say that but they do. Mitsui also makes nice grinders, I preferred them in the shop over some other makes and purchased one for my home shop. Glad to hear you're getting started with some results that meet your expectations. Be safe.
 
Agree, Okamoto makes a nice grinder, Mitsui also good machine..still it is a good idea to pull the table on ball and roller machines every few years for a cleaning...nothing wrong with a Chevalier Its all/much about condition and care..
 
Just one more safety tip. It is possible to explode a wheel when you are approaching first touchoff, if you screw up and jam the wheel into the workpiece. I know, because I did it in a machining class once. Fortunately for me none of the wheel fragments hit me. Scared the beejezus out of me though.

I did that on our bigger Okamoto, 2x12 wheel I think. I was being reealll careful because I had a shaky setup (I should have stopped and done it right, but was just a 'quick job').... Touched off and part pulled out of the grinding vise and

BOOM!

Holy hell I about pissed myself! Luckily I didn't catch any of the wheel shards either.
 
Exploding a wheel is a scary thing even on a small 6 x 12 or a snag grinder. One of my first jobs as a machinist was as an OD/ID grinder. I was running an old Landis, a large one, with manual lever direction controls and carriage return stops. Works ok when new but this one had a lot of slop in it and it didn't flip the lever enough so it paused and returned to go for the headstock. I panicked and vainly tried to change direction....all the way until the wheel crashed into the headstock and choked out the motor. Everybody else in the room headed for the hills when they saw the sparks. It should have exploded, it didn't but boy was I shook up. The rest of the crew drifted back in, told me to run like hell next time, then they all shook my hand and told me I was officially an OD grinder. Grinders can be explosively violent in the blink of an eye. I've never exploded a wheel, hope I never do either. I got real lucky that one time.
 








 
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