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  #1  
Old 11-22-2008, 10:33 AM
Phil O'Rourke phil_o is offline
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Default Sharpening carbide cutters

I googled "sharpening carbide cutters" and came up with this like http://www.askmehelpdesk.com/tools-p...lade-5743.html
Wondering if anyone has tried sharpening their own cutters. Im sure some cutters would be easier than others
  #2  
Old 11-22-2008, 11:08 AM
T.G. Marino tgm is offline
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Phil,
Sharpening your own cutters is not a 'do it yourself' project by any means. For the $10-$15 it costs to resharpen a $50-$80 cutter, why bother. And for the $12 ball mills etc, just throw them away. If someone is stupid enough to try sharpening a carbide cutter with a Dremel, just because you can buy a diamond wheel, let them do it. I can bet you the cutter won't be any good when they get done with it.
This is one job best left to the professionals.

Good Luck,

Tom in PA
  #3  
Old 11-22-2008, 01:29 PM
Don Kerschner don is offline
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Phil, One can sharpen their own tools.
But will take a fair amount of funds to purchase the right machine(s), even for the manual machines.
I've ground\manufactured tools for 10+ years.

Understanding the geometry of the tool and the purpose of said geometry then making sure its accurate to give you the best cut.

Just like cnc routing, grinding and resharpening tools has little things to watch for also.
Such as making sure the primary or secondary reliefs don't heel (higher than the cutting edge)
Using the right wheel
The correct RPMs to grind with.
Spark out passes.
Making sure the same amount taken off each flute so the tool stays round and concentric....
Here is a thread over on Vectrics forum with some basic tool geometry and info.
http://www.vectric.com/forum/viewtop...mp;hilit=sharp

Like Tom mentioned, its easier to take your tooling to be resharpened and cheaper in the long run.
Find a local grinder, Gather up your tools and go talk with him.
Make sure he knows that any V Bits need that a true point, and they can even mic your single fluted cutters.
And if you only want .002 off the diameter they can do that.
But it usually takes approx. .006-.012 to clean up most chips and wear.
They also can help you with putting a coating on your tools for longer life (usually for metal work), polish the flutes for plastic and aluminum work. (this keeps the material from sticking to the flutes).
Anyway.. visit your local tool grinder.
Or feel free to email any other questions if you feel you need direction in what you need and how to grind your own tools.
  #4  
Old 11-23-2008, 08:24 AM
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Michael Miller gundog is offline
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This is the cheapest tool grinder I have seen but I don't know anyone that has one. I have thought about buying one not so much for saving money on sharpening but more for the convience of not waiting for a sharp bit.

http://www.harborfreight.com/cpi/cta...emnumber=45707

Mike
  #5  
Old 11-23-2008, 11:47 AM
T.G. Marino tgm is offline
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This el cheapo grinder will not do what you want to do with it. Read the product manual carefully before you buy. A title of 'Universal Cutter and Tool Grinder' says all.
You will be spending mucho more than $629 to get decent equipment to grind carbide router tooling. I am sure Don above will verify that.

Be wary........

Good Luck,

Tom in PA
  #6  
Old 11-23-2008, 08:16 PM
Don Kerschner don is offline
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After looking at the link Mike posted.
The Universal Cutter Grinder might be good enough to sharpen the flat faces of some router bits,putting lands on Vbits, But will not be able to sharpen the diameter of any type of tool that has a spiral flute.
But this ad doesn't say anything about a Diamond cup wheel coming with the purchase.
And thats the only type of a wheel good for reshapening carbide. An estimate of a diamond cup wheel for this grinder would be approx. $120-$150 dollars.
I do not sharpen any of my own tooling at home.
I take it to work. No favors I'm a paying customers, this way I can complain and make sure that the grind is right and exactly how I want and on a timely manner.
If I was to purchase or make a grinder, It would be a cutter master as I feel its the most suitable for spiral work and with the right attachments one could sharpen ballnose tooling also.
A quick google search on a cutter master gave me this link.
http://www.penntoolco.com/catalog/pr...ategoryID=5833
  #7  
Old 11-24-2008, 10:38 AM
Mike Richards richards is offline
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Remember that the cutter is going to be spinning at 12K to 24K. If sharpened incorrectly, the cutter is going to be out of balance. Buying a new router or replacing the bearings in a spingle to save $8 is poor economics.
  #8  
Old 12-04-2008, 01:01 PM
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Michael Miller gundog is offline
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The bits I use are $60-$70 each. I have seen people sharpened mill bits on a carbide grinder with a spin indexer with good results. I am just touching up the flat faces but that is what seems to dull the fastest for me.

The machine I posted might be a POS or not I don't know. I have thought about buying one but I would like to put my hands on one first and the HF near me does not have one in stock.

Mike
  #9  
Old 12-04-2008, 04:56 PM
Don Kerschner don is offline
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These spin indexers are a neat fixture for several things.
But if you use this to sharpen the diameter.
You will need to indicate the tool with in at least .0005.
If you can find a way to pull the tool the full length of the flute, OR make the wheel travel the full length of the flute. This is called cylindrical grinding.
The trouble with this is that if that primary land(on the diameter)gets to wide, and when you go to use this tool, If your feed rate is to fast, this could cause this tool to heal, possible ruining your part.
Also you shouldn't grind the end flat, not allowing the proper clearance for chip evacuation.

Here is a link with lots of good information from The Weldon Tool company.
From their tools to tool geometry, guidelines what the primary, secondary relief angles, and how to sharpen tooling.
http://www.endmills.com/catalogs/weldon/Weldon1998.pdf
  #10  
Old 12-04-2008, 05:43 PM
Gabe Pari gabepari is offline
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Michael, I think Mike Richards was referring to the cost of having them professionally sharpened not the cost of the bit. I use bits that are $60-$70 each as well, some are over $100. When they need to be sharpened I take them to a professional and its $5-$10 per bit.

Why risk ruining a high dollar bit to save a few bucks? An end mill cutter is spinning maybe a couple of thousand rpm when cutting steel, faster for AL, but that is a big difference from spinning 20K+ rpm on a spindle/router.

Gabe
 

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