I watched the asc65 site for months , it’s never in stock.
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Sharpening carbide end mills?
- Thread starter Janger
- Start date
I tried out the aliexpress grinder - thanks to the owner. I think the key to these lower end asian grinders is knowing what they are good for. They are good for single lip cutters like engraving cutters, for modifying EM's by reducing the neck or shank, good for lathe tools and for forms tools, good for making shaper tools, and end mill ENDS or sharpening the bottom flutes.
For side flutes on end mills there is another attachment and another story. This attachment holds the EM and allows you to rotate the EM and slide it back and forth at the same time. The sliding surface between the cast block and the machined collet holder has to be extremely precisely made (within tenths I would think) or the EM wiggles back and forth in relation to the grinding wheel. That wiggle makes it really hard to get a good edge. Also there is a pin which follows the groove in the EM in order to rotate the EM correctly and keep the edge precisely aligned to the wheel. This is quite tricky to adjust correctly and this also needs to NOT flex at all. There are a couple of other complications I won't go into. In Stefan's you tube video overview of these tools he says the machines are not rigid enough to support flute milling and he sold his attachment for that and does not do that op on his machine. I think I'm back to sending out my EM's to sharpening.
For side flutes on end mills there is another attachment and another story. This attachment holds the EM and allows you to rotate the EM and slide it back and forth at the same time. The sliding surface between the cast block and the machined collet holder has to be extremely precisely made (within tenths I would think) or the EM wiggles back and forth in relation to the grinding wheel. That wiggle makes it really hard to get a good edge. Also there is a pin which follows the groove in the EM in order to rotate the EM correctly and keep the edge precisely aligned to the wheel. This is quite tricky to adjust correctly and this also needs to NOT flex at all. There are a couple of other complications I won't go into. In Stefan's you tube video overview of these tools he says the machines are not rigid enough to support flute milling and he sold his attachment for that and does not do that op on his machine. I think I'm back to sending out my EM's to sharpening.
I think your statements about rigidity for flute grinding are quite correct and these single lip cutter grinders (which is what they are actually a clone of: a Deckel SO) are not designed for that.
Now, a bigger T&CG like a Cincinnati, KO Lee or Clarkson, etc. were used for decades (long before carbide and CNC grinders were popular) to grind all the cutters used in a machine shop.
Unfortunately, I do not have my Clarkson set up properly to help you out right now. I do have the correct flute grinding attachment for the machine. So in theory anyway, I should be able to do the job. But I lack experience and the shop is in disarray as we are still in the final stages of construction - which is moving along only at a snail’s pace as I try to get other projects for people done.
Now, a bigger T&CG like a Cincinnati, KO Lee or Clarkson, etc. were used for decades (long before carbide and CNC grinders were popular) to grind all the cutters used in a machine shop.
Unfortunately, I do not have my Clarkson set up properly to help you out right now. I do have the correct flute grinding attachment for the machine. So in theory anyway, I should be able to do the job. But I lack experience and the shop is in disarray as we are still in the final stages of construction - which is moving along only at a snail’s pace as I try to get other projects for people done.
I was looking at other equipment and came across this machine. They have a good video on sharpening using one of their machines. The collet is supported in an air spindle so the EM moves very freely and follows the pin easily. Interesting equipment. $4K and up.
Tom Kitta
Ultra Member
Carbide when sharpened looses the coating and is just a bare carbide. Bare carbide is only really good for AL. So there is this little point. Hence why all end mills for steel these days have some coatings. Hence why it does not make sense to sharpen 3/4 EM for 69 CAD if for a bit more you can get brand new Chinese EM 20mm that will easily out last the sharpened EM (for steel).
For AL bare carbide brand new 20mm is 90CAD - why would you spend 69 to sharpen EM if price difference is only 20 bucks and you get consistent sizing - only thing I can think of is trying to get every last $ out and not using a CNC.
Same size for steel is $100. Here sharpening would be not economical - $100 EM would out last 2x sharpened EM at 69x2.
This is why there are so few sharpening shops - it just does not really make economical sense. Also this price is for large EM - for small stuff like 12mm it totally makes zero sense commercially.
I do have TCG also not operational yet but I was more thinking of using it for other stuff - like for sharpening cutters for horizontal mill. Or sharpening large taps. EM sharpening would be more just for fun & not really needed that much.
In HS carbide EM 12mm lasts probably at most 1/2 of what it does in a CNC shop. Still till the bloody thing is dull it produces around 1 bucket of steel chips (like pail from Home Depot that you can buy for $5). I expect at least double in CNC. For HS that is a lot of steel. About half of my EMs end up dull and half die in accidents. This is in 50% mild steel and 50% in 4140.
For AL bare carbide brand new 20mm is 90CAD - why would you spend 69 to sharpen EM if price difference is only 20 bucks and you get consistent sizing - only thing I can think of is trying to get every last $ out and not using a CNC.
Same size for steel is $100. Here sharpening would be not economical - $100 EM would out last 2x sharpened EM at 69x2.
This is why there are so few sharpening shops - it just does not really make economical sense. Also this price is for large EM - for small stuff like 12mm it totally makes zero sense commercially.
I do have TCG also not operational yet but I was more thinking of using it for other stuff - like for sharpening cutters for horizontal mill. Or sharpening large taps. EM sharpening would be more just for fun & not really needed that much.
In HS carbide EM 12mm lasts probably at most 1/2 of what it does in a CNC shop. Still till the bloody thing is dull it produces around 1 bucket of steel chips (like pail from Home Depot that you can buy for $5). I expect at least double in CNC. For HS that is a lot of steel. About half of my EMs end up dull and half die in accidents. This is in 50% mild steel and 50% in 4140.
Interesting ideas on coatings Tom and price vs life. Taylor recoats the EM - maybe part of why it’s pricey. I’m expect a nearly new and accurate sizing. At Alex’s shop they send hundreds of EMs at a time to get them sharpened - I imagine a much better price due to their volume. I do wish it was cheaper and the chinese EMs sure are competitive. I have quite a few and they are good.
Tom Kitta
Ultra Member
Coatings are explained in detail on the web - I read about them recently. There have been a lot of studying done to figure things out. This is why a good coating is definitely worth it - there are tables that show you how much faster you can run your EM and how much more it will cut.
Alex shop does indeed needs to get a better price deal to make it competitive or they simply may not know any better - would not surprise me.
Each time EM is re-sharpened it gets... smaller - thus your sizing is off a bit. I guess the shop can tell you the new size. This is also the reason why you cannot re-sharpen EM infinite # of times - the angle would change too much. I have some large EM from E-bay and they been re-sharpened so much that from 1" they went down to like .9. I think general rule for say 3/4 is 3 times or so I heard - so just a more then a guess.
The new TCG are CNC based so re-sharpening say 100 3/4in EM may be just a simple run of a program - thus much cheaper in such volume. Say 100 same brand 3/4in EM of same size, first re-sharpen. Once re-sharpened their size drop to say 0.725 - now you have 100 EM of 0.725 sizing. Can easily program that into a CNC as a new tool.
Alex shop does indeed needs to get a better price deal to make it competitive or they simply may not know any better - would not surprise me.
Each time EM is re-sharpened it gets... smaller - thus your sizing is off a bit. I guess the shop can tell you the new size. This is also the reason why you cannot re-sharpen EM infinite # of times - the angle would change too much. I have some large EM from E-bay and they been re-sharpened so much that from 1" they went down to like .9. I think general rule for say 3/4 is 3 times or so I heard - so just a more then a guess.
The new TCG are CNC based so re-sharpening say 100 3/4in EM may be just a simple run of a program - thus much cheaper in such volume. Say 100 same brand 3/4in EM of same size, first re-sharpen. Once re-sharpened their size drop to say 0.725 - now you have 100 EM of 0.725 sizing. Can easily program that into a CNC as a new tool.
[mention]Tom Kitta [/mention] I would be interested in knowing/seeing more on the air bearing setup
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Brent H
Ultra Member
@Tom Kitta : do you have the Weldon air bearing End mill sharpening attachment?
I have the Weldon (non air bearing) sharpening attachment and 2 collets. I will either be making collets or trying to buy them.
I have the original manual for the holder if you want a copy.
I have 2 spindles for the holder, one for the wee end mills and one for the larger ones up to 1”.
I have the Weldon (non air bearing) sharpening attachment and 2 collets. I will either be making collets or trying to buy them.
I have the original manual for the holder if you want a copy.
I have 2 spindles for the holder, one for the wee end mills and one for the larger ones up to 1”.
Dimensions Tom ? How long is the spindle? How long is the cast iron block? Looks pretty beefy. What kind of collets does it use?
So If I'm following this, the air supply does not 'rotate' the spindle, simply enables the smooth manual turning (rotational) and lateral (left/right) movement?
Correct.
Tom Kitta
Ultra Member
I have almost identical air spindle as Tom O - same design but I think mine is smaller - also not in such great condition. Mine takes strange collets and size seems to top out at 1/2in but can load 3/4 straight in.
I also luck the end mill guide. Or a "stop" to guide in the EM helix.
I also luck the end mill guide. Or a "stop" to guide in the EM helix.