of dressing the green silica(?) grinding wheels used for Carbide lathe tools?
Roger in Vegas Pets have owners. Cats have staff.
of dressing the green silica(?) grinding wheels used for Carbide lathe tools?
Roger in Vegas Pets have owners. Cats have staff.
My personal choice has always been with a dressing stick. As much as some rave on about star dressers, they are very wasteful of grinding wheels, and difficult to use in getting a grinding wheel to run true, something that is very important when grinding toolbits. Dressing sticks (the sintered type, not the solid boron carbide variety) will leave a sharp surface, almost as good as the star dresser type, and will do it without wasting any of the wheel. You're likely to not see any difference between one dressed with a star dresser and the other with a dressing stick in how they cut but you will see the difference in how well the wheel turns out.
Dressing green silicon wheels (and black ones as well) is very bad for your health (silicosis). Breathing the dust should be avoided at all costs. Dressing with a star dresser really compounds the problem because so much more of the wheel is wasted.
I'll give it a try. They have a diamond point dresser that are cheap , maybe $14. You'll need some kind of cross slide to hold it. IIRC they should be set up into the wheel and take light passes until you get a steady cut. I can't remember if it strobes or you listen or both. I'm sure it could be done by hand if your really careful. Maybe drill a hole in the end of a steel bar for it to go into and a set screw and a sturdy straight edge in front and or side of the wheel. Best to make something up so you don't have to worry about it grabbing. I need to get around to doing this myself also.
Diamond wheel dresser. Pretty cheap.
All the supply companies sell them. $20 or so in the US.
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Glendo makes a diamond wheel dresser that is essentially a heavy, flat section of blue spring steel that carries a diamond dresser. The diamond stick is adjustable longitudinally (in and out ??) and you just flex the spring steel carrier and let it return with the diamond against the wheel.
I'm not familiar with those. How to they compare to a diamond dresser?
For dressing wheels on a pedestal grinder, they are far superior. Diamonds leave a wheel very smooth, necessitating greater pressure be applied to get good grinding action. Wheels so dressed are very poor for grinding tool steels. You might say that the wheel starts behaving like a bearing instead of a grinding wheel. A dressing stick, being softer than diamond, will remove bits by breaking the bond instead of cutting them like a diamond does. That yields a far better (slightly rougher) surface for off hand grinding, yet it is easy to get the wheel running true and flat.
Diamond dressed wheels cut very hot as compared to those dressed by a star dresser. On machine tools with rigid setups and flood coolant, that's not an issue. The problems of a star dresser have already been discussed, so what you get is a compromise of the two when you use a dressing stick. Dressing sticks are generally made of silicon carbide (or they may be boron carbide) and resemble a hand stone, usually about an inch square, six inches long, very coarse, perhaps 24 grit, and not expensive. The only negative effect of using one is that they have a slight tendency to dull abrasive grains that do not get knocked off the wheel. The surface they yield is a good offset, though, so they are a good dressing device, especially for grinding HSS. I highly recommend one for any shop.
For dressing the wheels on bench grinders I have always liked the clustered diamond ones. The rectangular ones about 3/8 x 1" with a handle, looks like a T with a real narrow top.
How's the snow, Harold?
Aside from the way-too-smooth surface created, they do an outstanding job. I still prefer a dressing stick over them. Or both, one to get the wheel running smooth and flat, the other to produce a better surface for grinding manually. If you haven't done it, it's hard to understand. I have. I do. Lots of converts to "doing it right". :-)
Yeow! 15" on the ground and it's snowing as we speak, with below freezing temps over the past couple days. Weatherman said we can expect the most severe snow storm we've had in years. It's going to be a long night! Supposed to turn to rain after a foot or so drops in the next 24 hours. Worst weather I've seen since moving here in '96. Figures!
Harold & Susan Vordos scribed in :
yes, I've noticed that. but, having only a diamond dresser (all I could get would you believe) I'll not give it up. out of true grinding wheels give me the absolute heebies
swarf, steam and wind
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And there's no need to. Using the diamond to get a wheel running true is the best of all worlds. The trick to getting the wheel to cut freely is then to touch it with the dressing stick, which roughens the surface every so slightly, making it cut much better. For a few bucks you can see for yourself. I promise you you won't be disappointed.
Hmmm.. my rememberer is too slow, but my forgeterer makes up for it by being too quick!! So I can't recall what it was you did to protect the house project for the winter. Is it something that you have to keep brushing the snow off to stop accumulation? Hate to think you and the missus have to do a "navy watch" system every night you get some frozen precip.
Take care. D>
I kinda missed where this thread was going. Are you advocating use of a stick for touch-up after truing with the diamond on my surface grinder and on my Black Diamond drill sharpener?
You know, I've got some dressing sticks I picked up with wheel stones at auctions. At least one white and a few black, but never used any of them. Sounds like I should learn. Does the stick "colour" mean anything we should know about, say relative to colour of the wheels?
Hey Brian, No, never for machine type grinding, that defeats the purpose of the diamond. Conditions on a precision machine are far different from offhand grinding, though. I'm not certain when diamonds became the dressing tool of choice, but there was a time when precision grinders were dressed with star dressers. In today's demanding world of precision and fine finishes, that wouldn't fly.
The point of my post is that dressing wheels with a star dresser is wasteful, and achieving respectable results can be difficult. A diamond works very well for truing the wheel, but the superior finish it leaves on the wheel creates a couple problems that are not in the best interest of offhand grinding, especially tool bits. Because of the slick nature of a diamond finished wheel, it takes considerable more pressure to get the wheel to cut. It also cuts one hell of a lot hotter. Anyone that knows enough to run a cutter grinder knows that wheels are hand dressed when sharpening end mills. That prevents over heating of the cut, and the wheel demands dressing often to maintain the cool cutting condition. The same principle applies to offhand grinding. By using a dressing stick, the wheel is slightly roughened, which lowers cutting pressure tremendously, and heating as well. That is not to say that diamonds don't have a place on cutter grinders, or on pedestal grinders, but you have to know when to use one, and when not to. There's nothing wrong with using a diamond to get a wheel running true, but it should be slightly roughed up with a dressing stick before using it to grind offhand. If that's not right, then the shop where I was trained did it wrong for years.
Fine grained dressing sticks that are white are primarily intended for dressing diamond wheels. Yeah, I know, that sounds nuts, but diamond wheels get loaded with particles and get glazed such that they start not cutting well. By running a fine stone on the diamond, the crud is removed and the wheel surface restored. You're not really doing anything to the diamond, and if you do, you're doing it wrong. The dressing operation should do no more than clean the wheel, and the diamond tends to remove material from the dressing stick, as it should be. You don't want to remove the matrix bonding the diamond for obvious reasons. Dressing diamond wheels should not be a prolonged operation, one should stop the moment the wheel is cleaned.
The dressing stick I used for years for that purpose was black in color, but a friend recently gave me a new one, which is white. The black one is no doubt silicon carbide, the white one aluminum oxide. Both will clean a diamond wheel, and I have no idea why they are made from both abrasives. In the scheme of things, the aluminum oxide one would certainly be softer, kinder to diamonds, but the hardness difference between diamonds and silicon carbide is so great I'm not convinced it makes a significant difference.
If you have in your collection of dressing sticks one that is very coarse, made of shiny black bits of abrasive, it is most likely a silicon carbide stick made for dressing aluminum oxide grinding wheels. There would be no harm in trying it on a grinding wheel on your pedestal grinder, which is where I highly recommend these items be used. If it is a dressing stick, the wheel is readily abraded. I suggest you not use a white one on an aluminum oxide wheel, use only a black one.
It was common practice for us to use dressing sticks to relieve the sides of wheels when we had face work to do. Even on precision grinders, face work is generally done with hand dressed wheels, and for the same reasons, keeping heat down. It was not uncommon to get heat checking on faces of heat treated tool steels otherwise, so how the wheel was dressed was rather critical. Face grinding keeps a lot more of the wheel in contact, so more heat is generated. The rapid heating and subsequent quenching by coolant was the source of heat checking. Hand dressing is almost mandatory for that operation. That would be true if the side of the wheel was used to kiss the face. If the wheel head is turned, a right angle is dressed on the wheel and grinds both the cylinder and the face with the periphery of the wheel. By grinding that way, the problem of heating is reduced to manageable levels.
Hope this helps~
I ended up draping a string reinforced visqueen tarp over the interior, which is supported in the center by the floor trusses of the second story of the house. The sub-floor is not installed. The tarp drains from the center, and there are temporary crickets directing the water towards the drain, which is 3" diameter drain pipe. It's worked pretty well so far, but anything that hits the roof ends up going down the drain, nothing comes off the sides because the tarp is, for lack of better description, a very flat funnel, only about 20" taller on the edges than the center. In order to prevent snow from tearing it down, I've had to get up on a ladder each day (that it snowed) and reach in as far as I can with a broom and drag the snow off the outside edges. It's complicated by the rebar that's on 15" centers sticking up. the rebar, however, is the anchor point of the tarp, so it serves a useful purpose in spite of being a PIA. Of all years to get record snow, naturally it had to be this one. We have about 19" on the ground now, it's put down 4" since late last night. If we make it past today, we're supposed to warm up. It's been interesting, Brian! What really irritates me is last year we had no snow.
I appreciate your concern.
And where in WA state are you? Vancouver, Yelm, Seattle, Bellingham, Spokane?
I agree with Harold in all respects save one. If you have a badly worn bench grinder wheel and you want to get it flat again, a star dresser will do the job much faster than anything else. That's why I keep one in my shop.
Harold & Susan Vordos wrote:
I agree that the star dresser could be faster under that circumstance. I'm not convinced it would beat a diamond, though. Another very good use for the star type dresser is on larger wheels used in welding shops. Star dressers, just like diamonds or dressing sticks, have a place. It's a wise person that knows when to use the right one.
Just outside a little town called Onalaska. It's south and east of Chehalis (I-5 corridor). We're roughly half way between Portland and Seattle. We live on a ridge at about 1,300 feet so we regularly get snow when the valley doesn't. Since my last post it has put down two more inches, so we're now at 21". Makes me think I'm back in Utah. :-)
Yes I know where that is. I live in Arlington, 50 miles north of Seattle. We've got about 5" of the white stuff. Weather man says the snow should all be gone by tomorrow afternoon.
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