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
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