sumu 24th October 2007, 05:44 PM Hello, kinda sharpening topic.
Industrial diamond dresser has been common tool when opening/sharpening/dressing a bench grinder wheel.
Norton offers those Norbide CBN-sticks for the same purpose. It's advantage over diamond is better heat resistance.
But does it make difference any other than just allowing me to push the stick against the stone longer time at a time?
What's the difference in practice, any experiences?
kippis,
sumu
Alastair 24th October 2007, 05:54 PM Hi Sumu
To my mind, the disadvantage would be that they would tend to blunt the wheel more, by wearing down the grits. The diamond, (particularly single point which I use) tends to knock out grits, leaving the wheel sharper.
In either case, the intention is to round the wheel, making it evenly circular. To 'sharpen' one should rather use one of the dressers with multiple toothed wheels, as these spin and knock out the worn grit, revealing fresh sharp edges. They are not as good at trueing up a wheel, however.
regards
martrix 24th October 2007, 08:45 PM no contest for me. I have used both. Get a diamond dresser, preferably a t-shaped one like this.
http://www.woodworkforums.ubeaut.com.au/attachment.php?attachmentid=58639&stc=1&d=1193219133
jmk89 24th October 2007, 09:57 PM Hi Sumu
To my mind, the disadvantage would be that they would tend to blunt the wheel more, by wearing down the grits. The diamond, (particularly single point which I use) tends to knock out grits, leaving the wheel sharper.
In either case, the intention is to round the wheel, making it evenly circular. To 'sharpen' one should rather use one of the dressers with multiple toothed wheels, as these spin and knock out the worn grit, revealing fresh sharp edges. They are not as good at trueing up a wheel, however.
regards
I agree - one of these (from Dawn Tools (http://www.dawntools.com.au/products1.php?cat_id=23#p130)) gets the muck out of the wheel:
http://www.dawntools.com.au/images/products/medium_product_img1_23e_130.jpg
Then one of the Tee bar diamond dressers gets it nice and even and round.
martrix 24th October 2007, 10:31 PM I agree - one of these (from Dawn Tools (http://www.dawntools.com.au/products1.php?cat_id=23#p130)) gets the muck out of the wheel:
http://www.dawntools.com.au/images/products/medium_product_img1_23e_130.jpg
Then one of the Tee bar diamond dressers gets it nice and even and round.
ooh yeah, haven't used one of those. Need one of those at work, so many people just load up the wheel and no one (except me) gives the wheel any attention. The diamond dresser does an OK job, but that thing would clear out all of the embedded gunk, no?
What are they worth?
China 24th October 2007, 10:46 PM The CBN sticks if they are the small square ones you are talking about, are more for shaping the stone rather than truing it
scooter 24th October 2007, 11:08 PM I think the better process, if you have both the T bar & the star wheel dressers, would be to true the wheel with the T bar unit first, & then sharpen it with the star wheel jobbie.
JDarvall 24th October 2007, 11:43 PM I use a dimond dressor. Never used a T-bar one. Just the ones that look like pencils..
But I've made a jig to hold mine so I can dress the wheel dead straight and square, which I value for grinding. I've got a picture here somewhere if interested.
Cliff Rogers 25th October 2007, 01:48 PM I use an old course grit grey wheel to dress the wheel true & flat & then sharpen it with a star wheel.
J.E. Mike Tobey 25th October 2007, 09:35 PM Just avoid cross-dressing.nIt confuses the steel.mt
sumu 25th October 2007, 11:55 PM Thanks fellas. It seems to be that I am the only person at our place to take care about those wheels, too.
I have had those narrow steel sticks with one piece of diamond. It's about time to get new one, so that's why I asked.
I have here that kind of carbide roll like jmk89 presented, too. It is a very good tool, indeed.
But I've made a jig to hold mine so I can dress the wheel dead straight and square, which I value for grinding. I've got a picture here somewhere if interested.
Bring it on, Jake :2tsup:. At least I can then make one and show to others how it works.
kippis,
sumu
derekcohen 26th October 2007, 01:03 AM I use two different dressers.
I use the diamond single point when I true up a wheel. This is inserted into a block of wood, which is my jig.
I use the diamond T-bar freehand when I just want to freshen up the wheel.
Regards from Perth
Derek
JDarvall 26th October 2007, 08:54 AM Bring it on, Jake :2tsup:. At least I can then make one and show to others how it works.
Gota a bit of time now.
First see if you like it. It may not be your thing. :wink:
picture 1 - my grinding setup. Its an old workhead driven by a washing machine motor.
I've got one of those tool rests below that I can spin away when I want to grind free hand........and above is the main tool rest(arrowed it).....Its just a bit of scrap steel that I lapped straight (enough:D) and bolted it on.
But for the jig to work this tool rest needs to have straight sides....
picture 2 - here's the jig.....diamond stick sitting in scrap wood. Just a hole with a kerf and a couple of wing nuts to lock the stick......and this scrap wood is screwed to a steel plate......:rolleyes:...and this steel plate is gripped by one of those cheapo sharpening guides you normally use of stones (but they've got a lot of uses. Handy things.)
That guides locked onto the plate pretty tight.
picture 3 - and when its time to dress the wheel, I place this jig up tight against that tool rest,,,,which locks it in the vertical (cause the tool rest has a flat side), and I just stroke it back and forth accross the wheel, which dresses the wheel parallel to the tool rest......ie. straight and square ready to grind.....grit goes everywhere :rolleyes:
picture 4 - And you just leave your jig like that. Prior to everytime you use it, you just tap it down with a hammer ever so slightly
When the wheels perfectly straight dressed like that, it'll impose a straight grind straight on your blades.....just a matter of pressing the blade in. Especially good for establishing profiles before you start grinding the bevel.
I've found a good dressing setup important, because the best tool grinding wheels are Aluminium oxide, and unfortunately they loose grit pretty quickly and deform, and you have to dress them often. But you'd know all that.
:wink:
sumu 27th October 2007, 06:03 AM Thanks, Jake. I got the idea :).
You know, one of my pals here uses very similar kind of home-made rail jig to sharpen his thicknesser blades. There is exactly similar kind of cheapo sharpening jig in use, but there it holds L-shaped piece of steel with one M20 threaded hole to hold Dremel drill, running diamond barrel grinding wheels. The angle of L-piece is not 90 deg, but adjusted to run the diamond bit along the bevel. He seems to be happy with it. There is a aluminium spacer block between the rail and the thicknesser blade, and the blade is attached there with powerful neodymium magnets glued in cavities made in aluminium.
(M20 is not actually quite correct thread, there is 3/4" x 10 TPI thread under the housing cap, but M20 fits well enough when started with 17 mm hole. It's just plastic :wink:, it obeys. )
I wonder why you did not build that over a bench grinder? For your style of grinding wheels, the wheel edges chip too easily? Diamond wears out too quickly?
One problem hereabouts is that we need green silicon carbide wheels for our carbide tools and HSS. Those stones are quite dense and tough, too, and they actually can't be used with ductile metals. (For such stuff, there is a big stationary belt sander with a plethora of different kinds of grit types).
Anyway, they will eat up the diamond quite easily especially with larger diameter wheels if held against the stone too long time. I been told that oxidation of diamond starts somewhere at 650 C, so care must be taken to maintain both.
kippis,
sumu
JDarvall 27th October 2007, 09:43 AM You know, one of my pals here uses very similar kind of home-made rail jig to sharpen his thicknesser blades. There is exactly similar kind of cheapo sharpening jig in use, but there it holds L-shaped piece of steel with one M20 threaded hole to hold Dremel drill, running diamond barrel grinding wheels. The angle of L-piece is not 90 deg, but adjusted to run the diamond bit along the bevel. He seems to be happy with it. There is a aluminium spacer block between the rail and the thicknesser blade, and the blade is attached there with powerful neodymium magnets glued in cavities made in aluminium.
Its sounds more advanced than my setup. Magnets and dremel. I think I know what your saying.
I have made up a jig for sharpening my jointer and thicknesser blades off that same tool rest. Been using for years....Take it straight from the grinder to the buffing wheels. Can show you that if you like. Something to laugh at. But it works !:D
Also use those same cheap jigs to re-grind plane blades bevels off that tool rest.
I wonder why you did not build that over a bench grinder? For your style of grinding wheels, the wheel edges chip too easily? Diamond wears out too quickly?
Well, at the time that was my idea I guess :wink:. And ...no, not that much wear to the diamond stick with these wheels. Their pretty soft.
I think I went through about 2 or 3 eight inch wheels before I had to replace the stick. That took a few years. And the diamond sticks are just cheapys. Under $20 each if I remember correctly.
I just wanted to be able to accomidate a few ideas with the design.
One problem hereabouts is that we need green silicon carbide wheels for our carbide tools and HSS. Those stones are quite dense and tough, too, and they actually can't be used with ductile metals. (For such stuff, there is a big stationary belt sander with a plethora of different kinds of grit types).
Anyway, they will eat up the diamond quite easily especially with larger diameter wheels if held against the stone too long time. I been told that oxidation of diamond starts somewhere at 650 C, so care must be taken to maintain both.
:- sounds like you know more about it than me......I stick with the really soft Aluminium wheels that heat up slowly because they throw grit fast. Works fine on carbon and HSS steels. But not on Carbide. I tried sharpening an old router bit with my wheels once and just too hard....all I did was wear the wheel away.
All carbide stuff get professionally sharpened or not at all.
Grahame Collins 28th October 2007, 09:27 AM Hi guys
If I can offer a me too?
Its a co incidence that I should see this post .On Friday I finished dressing all the wheels in the classroom workshops at school cos the safety inspector from WH&S was coming.
I had been previously been around and dressed them with the single diamond point that fitter had lent me. I found that the diamond tool bounces a lot on the wheels and they were not terribly concentric.
Having one of those Norton dressing sticks made of the similar material as the wheel but a tad coarser,I took it to school and went over the wheels as done by the diamond.
The stick leaves a much finer surface finish and the they are concentric and don't vibrate to the extent which they did before.
The bloody inspector turned up and said bugger all about my beautifully dressed wheels but plenty about the useless plastic guards ( the kids press them into the rotating wheels) and crash stops which are required at knee height on every machine.
I am impressed at the excellent surface of the wheel left by the stone.I have no trouble sharpening our biggest taper shank drills (25mm) on the large (350 diameter wheel) normally employed in grinding mild steel.
Grahame
Christopha 28th October 2007, 10:28 AM Diamond cutting wheels for the 4" angle grinder are great wheel dressers... Buy 'em from the $2 shop. They make great, cheap dressers. They usually cost about $12 for a pack of two.
rsser 28th October 2007, 10:50 AM I find the carborundum sticks do a good job of cleaning the Al. Ox. wheels but leave them too smooth. To roughen them (for betting grinding) I use the diamond point dresser, and use it roughly. Even then, when you feel the wheel surface its clearly smoother than the untouched wheel side. Seems a star wheel is necessary.
scooter 28th October 2007, 11:28 AM Great tip, Chris. :2tsup: Wish I'd heard of it a couple of years ago before I bought the single point & the T bar dresser... :D
I think I read somewhere that the single point dresser leaves the wheel "sharper" than the T bar type, but to achieve this the s.p. dresser must be moved across the wheel at a steady, not too slow, rate so it's not rubbing on the just sharpened abrasive. Hence the idea, taken to a conclusion, of the flash tormek dresser that has a "lead screw" type design.
I've found the t bar easiest to use, but intend making a copy of the Oneway jig like Stu from Tokyo made, that allows very small adjustment. Still need to hand feed across the wheel surface, though.
DJ’s Timber 28th October 2007, 01:18 PM Diamond cutting wheels for the 4" angle grinder are great wheel dressers... Buy 'em from the $2 shop. They make great, cheap dressers. They usually cost about $12 for a pack of two.
Not quite the same but along the same lines.
I used to do contract work brazing the diamond tips on concrete cutting blades and I asked the boss man if I could have a bit for dressing, so he gave me a bit of diamond impregnated carbide about 10mm x 10mm x 25mm to which I silver soldered a bit of rod onto it for a handle and this is the bees knees, it rips into grinding wheels beautifully.
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