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Thread: New wheels for the tool grinder- suggestions please?

  1. #1
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    Default New wheels for the tool grinder- suggestions please?

    So I've got one of those tool grinders with the two heavy cup wheels. One wheel is a white aluminium oxide and the other a green silicon carbide.

    You know the drill, white for HSS and green for carbide. But the white wheel is a really poor one. Very hard and seems to glaze quickly then it's mostly heat with very little effective grinding. And the green wheel is all but worn out.

    So what I'm wondering is if I can get a diamond and or CBN combo that will do both HSS and carbide. What I'd like is instead of one side for HSS and the other for carbide is a coarse side for rougher shaping and a fine side for final "honing" and touching up when the edge just needs to be refreshed.

    Is a coarse and fine combo that works as well for both possible?

  2. #2
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    most of the time I have a 46 grit cup wheel installed, irrc aluminum oxide. Like 99.9% Frankly I can't imagine changing wheels for a rough cut then a finish cut. Just use the 46. For, I'll call it static grinding, where the work doesn't rotate like say a lathe tool, you can get an very high finish with the 46 - just spark out (rock back and for a dozen times, takes less than a minute. You can get it to almost a mirror, certain it doesn't need stoning afterward.

    The problem to productivity isn't the wheel, its the small work piece that quickly overheats. I made a mister that solves that problem, you can just attack something if you have to really remove material. Mist coolant keeps the wheel clean as well. I did a lot looking around and reading accounts of others who've made them and concluded the mister has to have pressurized air and coolant with separate controls for each - you have to be able dial in the flows so you're getting droplets dropped at the right speed right where the wheel meets the tool with no misting.

    That imo is the trick, not different wheels, just one good one with coolant


    EDIT.....ahh, you're talking about what looks like a bench grinder with the side tables....I thought you were talking a T&CG
    Last edited by Mcgyver; 02-11-2019 at 11:52 AM.
    .

  3. #3
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    Can't help with your green wheel, but if I were you I'd use a star-wheel dresser to deglaze and open the white wheel, then dress it true with a diamond.

    metalmagpie

  4. #4
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    I have one side is CBN, the other is Diamond. I've never looked back. Both work fine for "roughing" and fine finish. IRRC... both are around 120. I don't use drip or spray coolant - just dips into the water when it's getting to hot to touch.

    Remember... grinding carbide has health risks... Take care.
    Last edited by lakeside53; 02-10-2019 at 11:40 AM.

  5. #5
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    Quote Originally Posted by metalmagpie View Post
    Can't help with your green wheel, but if I were you I'd use a star-wheel dresser to deglaze and open the white wheel, then dress it true with a diamond.

    metalmagpie
    It currently has the "donut wheels" which are a donut of abrasive bonded to an aluminium plate. The green one is down to less than 1/2" thick. And it never really did a great job on carbide. It removed material but I had to use a diamond hand slip to hone the edge to get it truly good to use and longer lasting.

    The white stone is simply not a good "bond". Namely it does not break down the way it should and stay "open" and expose new sharp edges. I don't use a star wheel on it because I was worried about doing so on a face style stone. But I do have a diamond "T" shaped dresser that I use frequently. And a single point diamond on a traveling holder to true the face now and then The issue is that the dressed face only cuts decent for about 30 seconds worth of grinding then it fades in effectiveness rapidly over another 30 second until it's right back where it started. Basically I've used better stones and this isn't one of them. Typical poorly graded stone just tossed onto a clone grinder.

    I had a regular flat Al-O wheel on a regular bench grinder that did have a proper "bond" spec for doing tools steel. Was truly a treat to use and lasted well too. But that is long gone. Plus I want to use the tool grinder I've got now which is a decent running clone of this Baldor grinder.

    Lakeside, thanks for the info. DO you use one for HSS and the other for carbide? Or just use whichever allows rotation to suit the angle being ground at the moment?


  6. #6
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    I use one for HSS and the other for Carbide. Sometime I cheat... Heck, It's my wheels I have that exact machine complete with the cast iron water container, but no water trays (one day). One thing I want to add is a foot pedal BRAKE! It takes forever to slow down enough to reverse direction.
    Last edited by lakeside53; 02-10-2019 at 10:34 PM.

  7. #7
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    I would love to see some more details on your mister. You say that the individual controls allow getting droplets right where the wheel meets the tool. And there is no misting. Sounds contradictory; a mister that produces no mist.

    I have always shied away from mist cooling as I would not want to breath in the coolant. I would like to see exactly how this works. Photos? What kind of nozzle? Pressures? etc. And how effective is it in keeping the coolant out of your lungs? Perhaps this with a good discussion of the theory behind it would even be the subject of a good article for one of our host magazines.



    Quote Originally Posted by Mcgyver View Post
    most of the time I have a 46 grit cup wheel installed, irrc aluminum oxide. Like 99.9% Frankly I can't imagine changing wheels for a rough cut then a finish cut. Just use the 46. For, I'll call it static grinding, where the work doesn't rotate like say a lathe tool, you can get an very high finish with the 46 - just spark out (rock back and for a dozen times, takes less than a minute. You can get it to almost a mirror, certain it doesn't need stoning afterward.

    The problem to productivity isn't the wheel, its the small work piece that quickly overheats. I made a mister that solves that problem, you can just attack something if you have to really remove material. Mist coolant keeps the wheel clean as well. I did a lot looking around and reading accounts of others who've made them and concluded the mister has to have pressurized air and coolant with separate controls for each - you have to be able dial in the flows so you're getting droplets dropped at the right speed right where the wheel meets the tool with no misting.

    That imo is the trick, not different wheels, just one one good one with coolant


    EDIT.....ahh, you're talking about what looks like a bench grinder with the side tables....I thought you were talking a T&CG
    Paul A.

    Make it fit.
    You can't win and there is a penalty for trying!

  8. #8
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    I was keen on a mister at one point but as I learned more about it I shied away for the same potential health reasons. But perhaps if one could produce more of a spitter or sputterer that blows larger droplets instead of a fog like mist? No idea how such a thing would work mind you....

  9. #9
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    A small motor driven rotary valve (rod with hole drilled across it and two o-rings) could be uses to control the spitting. Sigh... another project.

  10. #10
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    You mean like an intermittent squirt? I was thinking more along the line of air blown droplets that could travel for more distance. Like a badly operated spray gun that shoots out oversize droplets. That way the modest air pressure aids with blowing the chips clear at the same time it provides coolant lube.

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