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  1. #1
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    Default Lookin for some advice

    I've been trying my hand at learning how to grind. I've been reading a lot and have learned a lot.. I'm kind of going in blinr with no real help.

    Our shops grinder is pretty not so great and we run dry. I have an assortment of wheels, mostly 46ar jv40 carbo medalist. Lots of half inch wheels, bnut theyre all like 4 inches now or fucked. In 60grit and up it's largely 32ar carbo gold wheels, and they are again mostly down to 4-5 inches, and there is maybe one that is 1/2 wide still. theyre largely in jv40 but I think there are a few I's. 80 grit and up the pickings are very slim and they're all 1/4 or less in width. I found 3 brand new 8x1/2 inch 46ar medalists yesterday though so that was nice


    Anyway my question is, I've got some pretty critical clamping dies to grind down today that just came back from heat treat. Material is D2, 60-62hrc. I should have 5 thou on all the faces. It's going 5o require multiple jig set ups and qualifying every cut. The top of rhe part has a radius machined into it and all the dimensions center around this radius. Next to the radius are two 30 deg angles which must be ground within 2-4 thou off a 30 deg drawn from the center of the rad.. The bottom end of it has a lip on each side that forms a t slot to retain.

    My plan of action is to first luck the bottom locating surface and establish a height so I can calculate the intersection of the 30 deg angles and the side locating edges, which I will qualify on a shadow graph first and then use a surface gage set up to measure comparatively. I will mount the dies radius side down on a piece of O2 drill rod so that I can ensure an even height and parallelism.

    Next I'll flip the fresh ground face up against an angle plate and clamp with the drill rod again. Because of the angles I should have access to the top of the drill rod which I can use as a datum point for the sides I have to grind. Do one side, flip the part, do the other. I should also mention there is a shoulder so I'll have to grind the side of the wheel.

    At some point I'll also have to put the part back on its base to lick the lips to height. At the end I'll have to take them to length as well, So 6-7 set ups per partm

    I plan to do all 3 and leave the angles til lady and then I have to throw this big ugly compound vice on the table to grind the angles.


    My real question is, I have a brand new carbo medalist 1/2" 46ar j40 wheel I'm going to rough with, and I was thinking of one of the 1/4 32ar jv40 for finishing..

    But how should I go about switching wheels? Im going to have to spend a good bit of time locating and setting my dials, so I figure its best to switch the wheels. As I mentioned there is also shoulder so I'll have 5o relieve the face of my wheel - I was thinking about using a 3rd wheel, 32ar jv40 with the relief ground for the side so I can save the other two wheels..

    Any advice for infeed and doc? I had a hell of a time grinding 10 tho off rhe angles faces of our ither set of dies. Was usin 32ar60jv40. it took forever. I didnt know much about wheel grades and stuff then so I passed over tjhe 4 inch 46 grit medalists thinking that it would take me even longer with them.. im probably wrong tho


    Appreciate any advice. Thanks guys

  2. #2
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    Quote Originally Posted by GTM- View Post
    I've been trying my hand at learning how to grind. I've been reading a lot and have learned a lot.. I'm kind of going in blinr with no real help.

    Our shops grinder is pretty not so great and we run dry. I have an assortment of wheels, mostly 46ar jv40 carbo medalist. Lots of half inch wheels, bnut theyre all like 4 inches now or fucked. In 60grit and up it's largely 32ar carbo gold wheels, and they are again mostly down to 4-5 inches, and there is maybe one that is 1/2 wide still. theyre largely in jv40 but I think there are a few I's. 80 grit and up the pickings are very slim and they're all 1/4 or less in width. I found 3 brand new 8x1/2 inch 46ar medalists yesterday though so that was nice


    Anyway my question is, I've got some pretty critical clamping dies to grind down today that just came back from heat treat. Material is D2, 60-62hrc. I should have 5 thou on all the faces. It's going 5o require multiple jig set ups and qualifying every cut. The top of rhe part has a radius machined into it and all the dimensions center around this radius. Next to the radius are two 30 deg angles which must be ground within 2-4 thou off a 30 deg drawn from the center of the rad.. The bottom end of it has a lip on each side that forms a t slot to retain.

    My plan of action is to first luck the bottom locating surface and establish a height so I can calculate the intersection of the 30 deg angles and the side locating edges, which I will qualify on a shadow graph first and then use a surface gage set up to measure comparatively. I will mount the dies radius side down on a piece of O2 drill rod so that I can ensure an even height and parallelism.

    Next I'll flip the fresh ground face up against an angle plate and clamp with the drill rod again. Because of the angles I should have access to the top of the drill rod which I can use as a datum point for the sides I have to grind. Do one side, flip the part, do the other. I should also mention there is a shoulder so I'll have to grind the side of the wheel.

    At some point I'll also have to put the part back on its base to lick the lips to height. At the end I'll have to take them to length as well, So 6-7 set ups per partm

    I plan to do all 3 and leave the angles til lady and then I have to throw this big ugly compound vice on the table to grind the angles.


    My real question is, I have a brand new carbo medalist 1/2" 46ar j40 wheel I'm going to rough with, and I was thinking of one of the 1/4 32ar jv40 for finishing..

    But how should I go about switching wheels? Im going to have to spend a good bit of time locating and setting my dials, so I figure its best to switch the wheels. As I mentioned there is also shoulder so I'll have 5o relieve the face of my wheel - I was thinking about using a 3rd wheel, 32ar jv40 with the relief ground for the side so I can save the other two wheels..

    Any advice for infeed and doc? I had a hell of a time grinding 10 tho off rhe angles faces of our ither set of dies. Was usin 32ar60jv40. it took forever. I didnt know much about wheel grades and stuff then so I passed over tjhe 4 inch 46 grit medalists thinking that it would take me even longer with them.. im probably wrong tho


    Appreciate any advice. Thanks guys
    Some (not all) advice:
    Topic titles need to inform what your topic is actually about

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    First thing I thought of when reading this meaningless title was: Dont smoke in bed. Quickly followed by Dont piss into the wind.

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    Quote Originally Posted by GTM- View Post
    I've been trying my hand at learning how to grind. I've been reading a lot and have learned a lot.. I'm kind of going in blinr with no real help.

    Our shops grinder is pretty not so great and we run dry. I have an assortment of wheels, mostly 46ar jv40 carbo medalist. Lots of half inch wheels, bnut theyre all like 4 inches now or fucked. In 60grit and up it's largely 32ar carbo gold wheels, and they are again mostly down to 4-5 inches, and there is maybe one that is 1/2 wide still. theyre largely in jv40 but I think there are a few I's. 80 grit and up the pickings are very slim and they're all 1/4 or less in width. I found 3 brand new 8x1/2 inch 46ar medalists yesterday though so that was nice


    Anyway my question is, I've got some pretty critical clamping dies to grind down today that just came back from heat treat. Material is D2, 60-62hrc. I should have 5 thou on all the faces. It's going 5o require multiple jig set ups and qualifying every cut. The top of rhe part has a radius machined into it and all the dimensions center around this radius. Next to the radius are two 30 deg angles which must be ground within 2-4 thou off a 30 deg drawn from the center of the rad.. The bottom end of it has a lip on each side that forms a t slot to retain.

    My plan of action is to first luck the bottom locating surface and establish a height so I can calculate the intersection of the 30 deg angles and the side locating edges, which I will qualify on a shadow graph first and then use a surface gage set up to measure comparatively. I will mount the dies radius side down on a piece of O2 drill rod so that I can ensure an even height and parallelism.

    Next I'll flip the fresh ground face up against an angle plate and clamp with the drill rod again. Because of the angles I should have access to the top of the drill rod which I can use as a datum point for the sides I have to grind. Do one side, flip the part, do the other. I should also mention there is a shoulder so I'll have to grind the side of the wheel.

    At some point I'll also have to put the part back on its base to lick the lips to height. At the end I'll have to take them to length as well, So 6-7 set ups per partm

    I plan to do all 3 and leave the angles til lady and then I have to throw this big ugly compound vice on the table to grind the angles.


    My real question is, I have a brand new carbo medalist 1/2" 46ar j40 wheel I'm going to rough with, and I was thinking of one of the 1/4 32ar jv40 for finishing..

    But how should I go about switching wheels? Im going to have to spend a good bit of time locating and setting my dials, so I figure its best to switch the wheels. As I mentioned there is also shoulder so I'll have 5o relieve the face of my wheel - I was thinking about using a 3rd wheel, 32ar jv40 with the relief ground for the side so I can save the other two wheels..

    Any advice for infeed and doc? I had a hell of a time grinding 10 tho off rhe angles faces of our ither set of dies. Was usin 32ar60jv40. it took forever. I didnt know much about wheel grades and stuff then so I passed over tjhe 4 inch 46 grit medalists thinking that it would take me even longer with them.. im probably wrong tho


    Appreciate any advice. Thanks guys
    Some advice from a perspective that might seem a bit self-serving, but may in fact help you out. You might consider using CBN tools in this app...precisely because you won't have nearly as much worry with tool wear and resultant issues with straightness. The material you are grinding is super hard and right in the wheelhouse of a superabrasive.

    Now for the self-serving part...we manufacture CBN and Diamond shank-mounted tools. If you'd like a bit more insight, drop an email to [email protected], or check out our website Quality, Precision, Experience… - Diagrind Inc | Superabrasive Internal Grinding Wheels. The site lists basically all of our standard tools, but custom tools made for individual jobs make up about 75% of our business.

    -Mike

  5. #5
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    We grind a lot of hard D-2. A sketch or drawing would help you to get some real advice, but this will probably get locked before that happens. Need a better topic title. No idea how big your parts are, but CBN wheels are the thing to use. We use it almost exclusively for D-2 (unless you have to form grind).

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    Rough crowd eh, not like the guy is a hobbiest looking for advice on his 9" southbend.

    I'd offer some advice but I've never done what you are looking for help with.

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    First, I can't make heads nor tails of your wheel designations. Regardless of what they are called in the shop, use the entire code so we can see what you have. Since they are Carborundum brand and Carborundum and Norton are at the exact same address I would bet they are rebranded Norton products. If all you can find are stubs of wheels then either there is no serious grinding going on or the guys that do it are keeping the good wheels in their box. Tell us what the entire code on these wheels is so we don't guess. Have you any training on a surface grinder? Grinding can be a very dangerous job without some basic safety training and good work habits.

    And yes, that title won't fly.

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  11. #8
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    Like RJT says, get a cbn wheel, and some sort of coolant, even it it is a spray mist unit. Hardened D-2 is really tough to grind with aluminum oxide wheels, especially if you need to hold close tolerances.

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    Well, so far I've learned that the 15 dollar half carat diamonds are absolute garbage. Also 5hat an 8 inch wheel is too big for this machine.

    I didn't get the work done, I spent so long qualifying everything and getting my set up right. I hsd to lick my mag table 4 times.. - I cut it down with the mag on figuring that would be best to simulate pressure on it, but I still havd variation on my dial of up to a thou. Ground my angle plate to within a tenth and it looks beautiful. Really had to rip st it to avoid chatter. Used a 32ar 60 iv40 for that..



    this is what Im doin.. I was havin fun in mastercam.. went a little overboard it just started as a rough drawing.. lol

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    The designations I listed are all that are on the labels of the wheels.. The medalist wheels are the worst the majority of them have practically nothing written on them. Some literaply just have 46 written on them and nothing but a logo that says medalist and a bunch of long digit product codes, not the proper nomenclature. And that's the wheels with labels.. Or ones that are still legible. The carbo gold wheels make sense to me though, 32ar 60 Jv40, k40, IV40 etc.. Seems pretty on point with the wheel

    There is no serious grinding going on, the grinder in the shop was almost exclusively used by the cold heading guys in their dept to grind a few thou off dies or punches and cutters and those guys were total hacks. I've got a decade of multi spindle Swiss lathes, turning centres and milling experience, and I operate as sort of a do all where I am, programming quoting, maintanence work, lot of stuff youd have to call a tech for. I do my best 5o solve problems. I've recently gotten involved or thrown into wire bending and cold heading side of the company and in my investigations I discoveree just how bad things were over there. As such I've been remaching and regrinding their horrifically out of spec tooling.

    The machine really is in pretty rough shape. Im told there was a dro in it at one point jut I have to clamp indicators to the head and body and attempt to strategically place on them so I can get an actual reference without having to remove the parts.


    I have a box of wheels all used and stubs with various radii ground into them - but no radius dresser. The diamond dressrrs I had available to me were basically rounded over balls that didn't cut shit.

    Anyway man I don't see what the big deal is. Tueth be told I have so many questions about so many things in relation to grinding that I couldn't really be specific at all.

    Anyway it's becoming readily apparent to me that the wheels aren't cutting it. They make due because we aren't a grinding shop.. But we send out wo much shit that could be done in house.. Even though it's just absolutely mind numbing how long it takes to set up, dial in and then qualify my cuts.. I'm working with very little, but I am constantly learning and hopefully on the right track..

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    This doesn't look like a difficult part but that's IF you have proper equipment for it. I've ground a lot of D-2 components for stamping dies and while it's a great material for certain applications it isn't a lot of fun to grind. For openers you'll have to control the heat generated that will cause thermal expansion as the wheel dulls/loads up. The other suggestions for a CBN wheel is sound advice but if you don't even have decent AO wheels I wouldn't hold my breath asking the company to purchase one. Most die shops I've worked at had few CBN wheels, mostly they would use ceramic wheels (at 1/2-1/3 the price of CBN) to get by. The better shops usually had a control that could reduce the wheel speed. Wheel speed reduction would increase the grinding pressure/force and more easily fracture the grains, thereby exposing sharp new edges. Without the control the wheel would just seem to glaze, rather than fracture and that started the excessive heat.

    The only solution was to plan when you would re-dress the wheel. If you've only got about .005 per side you can probably, with caution, grind this part with either an AO wheel or (preferably) a ceramic if the company won't spring for CBN. I wouldn't grind this dry, you want to control heat here so use flood coolant, a spray bottle, or even a wet rag between passes to keep the heat down. Be EXTREMELY cautious about using a rag near a grinding wheel, it can grab the rag in an instant and might cause the wheel to explode or suck your hand in (not kidding here). Move the table way out and lock the table travel when you do this. You'll need a strategy of rough grind, cool down to check critical dimensions, and finish grind to size. You'll know when it's time to dress the wheel because the sound will change slightly and the spark at wheel contact to workpiece will look slightly different. Even the ground surface will look a bit different when the wheel is getting dull. If you're getting burn marks on the surface it's way past due to dress the wheel. Use as coarse a wheel grit as possible that allows an acceptable surface finish. Dress with a sharp diamond, those ball bearing diamonds are too worn to produce good results and you'll be dressing far too often.

    I also have to ask if you have a decent grinding vise? The image you supplied shows the use of an angle plate used with 1-2-3 blocks. It's possible to get good results from this but every extra component used is a chance to get grinding crud in there and throw the work off perpendicular. Besides that you're using the sides to register the bottom. You start by grinding the largest surface, if there's enough material, so you reference all other surfaces from the largest plane. Using a grinding vise will allow easier indicating, with less chance for getting things cockeyed by using toe clamps as your image shows. If you don't have a radius dresser then how do you intend to create that radius? Do you have a comparator/shadow graph or some means for checking the radius? More info please.
    Last edited by AD Design; 02-07-2020 at 02:06 PM. Reason: Can't create cohesive thought

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    Man I've had a whirlwind of issues since my last post. I have to do some emergency milling but then I'll finally take a break and fill you all in, it's 730 now been here since 9, oof. It's been interesting. I never truly appreciated how much skill it actually takes to properly grind something, there's just so much to consider. I've learned so much

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    Default To The OP

    That's ok, everybody here understand what putting out multiple fires at work is like. You DID at least check in. Too many others post questions and then just disappear when asked for details, leaving everybody to wonder whether the post was a genuine call for assistance or just some slacker too lazy to do the research. Take your time to reply, the board will be here when you're ready.

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    OBTW- I wanted to point out your clamping method of using toe clamps. Too bulky, too many moving pieces to control, too wide and can cock the piece if not set properly. You'll need to obtain some parallel (Toolmaker) clamps like the attached photo. They aren't very expensive, can provide enough clamping force for grinding (more on this so do read about it) and can even be made yourself in an emergency. When using the angle plate, often required, a "C" clamp is too bulky and may not clamp on a narrow surface like your piece. Parallel clamps are what you want, use in pairs.
    parallel-clamp.jpg

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    Just gonna throw this in here but, I would clean up the bottom face on the grinder to pucker flat then Wire EDM the profile.

    D2 is Not impossible to grind with just general purpose wheels, just take it really easy, with coolant. but WEDM will piss through that job by the time you set up your sine table to hit that angle.

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    Luke- WEDM is one of the few machines I've not run so I have no experience to estimate with. Out of curiosity how much time would this take and what would be the expected profile tolerance for square and parallel to bottom if the piece were 4" (100.16 mm) long? Yes I know tolerance is inversely proportionate to cutting time. Nobody is holding you to a quote here.

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    Going by my experience on the sodick I use, one cut technology will make this part to within 2 thou no problem, time wise, I reckon 2-6 hours, but you could also just run it over night, you can’t set your sine table up when your at home in bed!

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    Quote Originally Posted by Luke.kerbey View Post
    one cut technology will make this part to within 2 thou no problem, time wise, I reckon 2-6 hours
    -"2 thou"? Is that .002(inches) or .002(mm)?


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