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Help me set this up. Sharpening carbide bits.

Kanman

Plastic
Joined
Nov 18, 2019
F3671925-DF04-42BC-846F-5935F5DB10E2.jpg

What Rpm to run drill press at?
Diamond wheel says 6700 max RPM.
Bench grinder is around 3400 RPM

This is a Stump grinder carbide tipped cutter I’m trying to sharpen. I’ve literally got 100’s of these to sharpen.
 
What part are you trying to sharpen? From the photo it looks like you're attempting to sharpen a concave on the bottom? Or are you reducing the diameter to remove chips from the edges?
That also looks like a diamond cutoff wheel, which I dont think will take much side force, mostly meant for plunge grinding / parting.
 
Is that wheel for a tile or ceramic cutter? If so then it will be REALLY slow to grind those parts. Highish speed will prob work better.

Ed.
 
Looks like it should work. Try it, you got hundreds to practice on. Carbide toolbits are usualy sharpened on a green wheel made specificaly for sharpening carbide. I would run the drill slow maybe 100 rpm?
 
Oh I had to read it a couple of times. Now I see what's going on. When sharpening Stump Grinder bits in this fashion, you will need to apply chain saw oil liberally.

Wear safety equipment and stand clear of the flying debris! :)

Really, this is not a good way to do this job. Please refrain from this endeavor and find a re-lapping service. Ask them if you can observe the operation.

Best Regards,
Bob
 
Well i fit works, people will say he is a genius, if it doesn't we'll say "I told you so"

I have no idea what OP is trying to do but it looks sketchy at best. I'd just send them out (or buy new depending on price and function).
 
For the OP:
Stump grinder "bits" are usually pretty chewed up by the time someone replaces them. Often there's at least .06-.10 of material that has to come off and that's a lot of carbide. Taking off that much material will generate a LOT of heat and will likely lead to thermal cracking that will fracture the edge the first time in use. I understand you wanting to do this but that set up, can't see the photo clearly, won't do what you want it to and/or may get you injured. Don't do this.


If the OP is another troll just yanking everybody's chain: Go F*ck yourself.
 
Soooo.....
Wheel around 3200, drill press around 5-10 RPM and about 5-10 gallons per minute of coolant (Think home garden hose full open)
Other end, slow speed grind with wheel around 50-100 RPM and drill around 50. Air blow and vacuum with a very long per part time (hour or more per piece) and a LOT of diamond wheels.
As AD Design said normal stock to be taken off is a lot on these things in rework and new bits are so often a better deal. 60 thou will usually leave some chips but make a workable bit.
People see the carbide sign on my door and walk in with a box full these or the other variants all the time. New is almost always cheaper.

That plated wheel on that grinder needs to be indicated true on the OD within 5 tenths to have any hope of living.
The drill spindle is not rigid and has no ultra fine feed. The part has to be offset from wheel centerline so that only one side is being worked on.

Did I mention dry grinding carbide, lung disease and cancer?
Novel approach but just is not going to work.
The first piece with a new wheel will grind reasonably but take some time, the second and third part will not.

Is the button concave? Nothing peels off carbide like a Blanchard but you would need a bunch of fixtures to load it and it only does flat.
To remove this sort of stock in reasonable time you would want 3 to 10 HP on the grinder spindle and lots of coolant.

It's great idea so kudos for that but the devil is in the details and this one will bite you. If only .002 wear or chips on the used or wanting to polish the face it's not a bad concept.
Bob
 
700 Series Stump Cutter Tooth & Nut (700GT) for Stump Grinders up to 40HP | eBay

Agree with Carbide Bob ..Only wet and perhaps 5 rpm for the spinning and better no spinning to rough them back and just push them into a wet proper diamond wheel to get the wear land off flat ended, and then just a little wet spinning to put back the dish to a sharp edge.
Wheel might be a 120 surface grinder diamond wheel knocked/locked in to .001 or so running true fot the spinning part..

steady 1/8"+ water hose would be ok. perhaps building a shield to keep coolant off the machine...
*Have an extra ground wire from any metal parts in the set-up

RPM at 3400 is Ok. Proper wheel would last a good long time on solid carbide.

A carbide grinder style grinder(home made OK. plate mounted wheel, simple v block to run them flat into the wheel for good eyeball flat. then set them in your spinning set-up to just grind the dish.
carbide grinder https://www.mscdirect.com/product/details/32739245

Yes a surface , tool and cutter, OD grinder would be better, then you could grind at the dish and do fine.
 
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Chain a bunch of them (more than 20) to the back bumper of your truck, and let the road grind them....while you go on your daily route, your making money !
 
Believe it or not,he COULD BE ON TO SOMETHING.fIRST, arange the grinder so that the swarrf is thrown AWAY FROM OPERATER. SECOND,the center of the grinding wheel should be on the center of the drill press spindle,BUT,BUT ofset toward the perifery of the carbide in such a manner that the wheel is forcing the perifery of the carbide toward the center of the carbide rotation.THIS WIL MINIMIZE PERIFERY CHIPPING.If the diamond wheel is course and only around 1/8 or less wide ,and the carbide is rotatine you WILL have a vbery efisient and free cutting situation. There will be very little recuting of chips. Yes,grinding makes chips,they are just smaller.Raising and lowering the quill whilst grinding might also help material removal.The picture is not very clear and most dont know what the bit looks like AND THE DRILL PRESS looks cheezy,so most think this is not worht considering.One reply mentioned grinding carbide with a green wheel,I dont know if this was ment to be a joke,but IN 2019 NOBODY SHOULD EVER BE USEING A GREEN SILICON CARBIDE WHEEL. Rather than attack this guy ,take a close look at what he is trying to do. Edwin Dirnbeck
 
Believe it or not,he COULD BE ON TO SOMETHING.fIRST, arange the grinder so that the swarrf is thrown AWAY FROM OPERATER. SECOND,the center of the grinding wheel should be on the center of the drill press spindle,BUT,BUT ofset toward the perifery of the carbide in such a manner that the wheel is forcing the perifery of the carbide toward the center of the carbide rotation.THIS WIL MINIMIZE PERIFERY CHIPPING.If the diamond wheel is course and only around 1/8 or less wide ,and the carbide is rotatine you WILL have a vbery efisient and free cutting situation. There will be very little recuting of chips. Yes,grinding makes chips,they are just smaller.Raising and lowering the quill whilst grinding might also help material removal.The picture is not very clear and most dont know what the bit looks like AND THE DRILL PRESS looks cheezy,so most think this is not worht considering.One reply mentioned grinding carbide with a green wheel,I dont know if this was ment to be a joke,but IN 2019 NOBODY SHOULD EVER BE USEING A GREEN SILICON CARBIDE WHEEL. Rather than attack this guy ,take a close look at what he is trying to do. Edwin Dirnbeck

Dude, you gotta lay off the meth.
 








 
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