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cutter grinder idea

garageguy

Super User
Premium Member
Guys, I have always wanted a grinder so I could resurect some of my end mills but grinders are usually too costly to be viable for a hobby guy like me. I have been pondering this dilemma for a while and the other day a bulb briefly flickered on in my brain. (dangerous , I know). A while ago I acquired an old Black and Decker Super Valve Service valve grinding machine. It runs, but it is missing a few pieces like the valve holder for grinding the end of the valve stem. Both stones are there as well as everything for refacing the valve. Before asking the big question, realize that I have not put a great deal of thought into this yet as I have alot going on right now, but,has anyone tried to adapt a valve grinder to grind end mill cutters? I am thinking only the end and not the side. What do you think? : doable ? stupid idea ? not worth the effort ? By the way I'm recently retired so would have some time for this in the future.
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
Guys, I have always wanted a grinder so I could resurect some of my end mills but grinders are usually too costly to be viable for a hobby guy like me. I have been pondering this dilemma for a while and the other day a bulb briefly flickered on in my brain. (dangerous , I know). A while ago I acquired an old Black and Decker Super Valve Service valve grinding machine. It runs, but it is missing a few pieces like the valve holder for grinding the end of the valve stem. Both stones are there as well as everything for refacing the valve. Before asking the big question, realize that I have not put a great deal of thought into this yet as I have alot going on right now, but,has anyone tried to adapt a valve grinder to grind end mill cutters? I am thinking only the end and not the side. What do you think? : doable ? stupid idea ? not worth the effort ? By the way I'm recently retired so would have some time for this in the future.

My own attitude on this prolly sucks, but at the basement cost of end mills these days, I'd rather buy new ones and spend my time doing other things. The only thing I grind anymore is lathe bits and fly cutter bits and boring bar bits.
 

Everett

Super User
I'm curious to see what you come up with for modifications as I've often wondered the same thing. Considering how the machines needed to be precision setups to start with, it would make sense that modifying one should be further ahead than starting from scratch.

And I totally hear you @Susquatch, as cheaper end mills are easy to come by, but it does sound like a fun challenge. That and I'd love to be able to resurrect my box full of 3/4" Us-made cobalt end mills as it would be a shame to toss them, lol
 

garageguy

Super User
Premium Member
Thanks for all the replies. One other factor I have to deal with is simply availability. As far as I know there are no local suppliers for cutters and ordering them takes 7 to 10 days. Thats frustrating when in the middle of a job. Anyhow, I am going to look into this some more and will post updates later. Cheers.
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
Thanks for all the replies. One other factor I have to deal with is simply availability. As far as I know there are no local suppliers for cutters and ordering them takes 7 to 10 days. Thats frustrating when in the middle of a job. Anyhow, I am going to look into this some more and will post updates later. Cheers.

Availability is an issue I think we all struggle with. It's one thing to get decent cutters but quite another to get one today.

I know it's not a good answer, but I tend to make volume orders for things I use a lot. I like to believe that this saves on shipping, unit cost, and timing.

I confess that a good tool grinder would be a great asset! I'm just not prepared to pay what they are going for. If I can ever find one at the right price I'll put a leash on it so it follows me home.
 

Mcgyver

Ultra Member
I am thinking only the end and not the side. What do you think?

I sharpen all my own cutters, and for endmills I most don't even bother sharpening the ends. Unless you are plunging, you are cutting on the side of the end mill. As I doubt plunging cuts are even 2% of what I do, its not worth it for most sharpening. ITs also a bit of a pita to properly sharpen the ends compared to the sides.

If you are sharpening the end, be aware the ends are not flat. They have a degree or two of taper up to middle, leaving the middle with some slight clearance so it is not rubbing - the end angle in the diagram below


Geometrical-parameters-of-an-endmill.png
 
I sharpen all my own cutters, and for endmills I most don't even bother sharpening the ends. Unless you are plunging, you are cutting on the side of the end mill. As I doubt plunging cuts are even 2% of what I do, its not worth it for most sharpening. ITs also a bit of a pita to properly sharpen the ends compared to the sides.

If you are sharpening the end, be aware the ends are not flat. They have a degree or two of taper up to middle, leaving the middle with some slight clearance so it is not rubbing - the end angle in the diagram below


Geometrical-parameters-of-an-endmill.png
I'm going to add that the newer cutters are no-longer equally spaced, to greatly reduce chatter, however if you are sharpening manually, does add an no complexity to it.
 

garageguy

Super User
Premium Member
So an option would be to just grind the end off until you get to sharp flutes again and not worry about the end. When the cutter gets too short toss it. which you would have to do anyhow.
 

garageguy

Super User
Premium Member
Good info. Nice to have a different perspective on what to do with these cutters and how to view prolonging their life. Thanks guys
 

thestelster

Ultra Member
Premium Member
@mc
So how do you cut off the ends of endmills? I have a whole whack of carbide endmills: 1/2", 3/8", and 1/4" which the tips are damaged, and I have to spend time searching for the one with the least damage.
 

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SparWeb

Active Member
If it's more than one or two, I would choose to have them sharpened, not do it myself.
If in Alberta, ask Allblades how much it costs to sharpen "X" number of "Y"-fluted endmills.
If you're elsewhere in Canada, you may find a local sharpening service.
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
If it's more than one or two, I would choose to have them sharpened, not do it myself.
If in Alberta, ask Allblades how much it costs to sharpen "X" number of "Y"-fluted endmills.
If you're elsewhere in Canada, you may find a local sharpening service.

This seems like a very practical and potentially cost effective solution.

If there is such an outfit out west, it only makes sense that there would by one or two in the east too.

Have you ever used them yourself or this something you ran across and are thinking about? Can you vouch for them?
 

SparWeb

Active Member
I have used their service myself from time to time. A friend of mine did more regularly, running a HAAS CNC, and I remember him sticking with them for a while. Back then he had "batch" projects that would use up tooling, then he'd fix or replace things that broke, or sharpen what was dull, to be ready for the next lot.
 
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