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  1. #21
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    I used to use a lot of Garr carbide end mills in a former shop. Garr will regrind their end mills at a substantial savings, and the tools cut as good as new ones . . .I had never experienced this before using this service. Usually only resharped the 1/2" and 3/4" as I did not think the smaller sizes worth the effort.

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    Blunt 2 fluter's are dead easy to free hand the bottom of on a bench grinder to make into a counter bore. I have a 9/16" cutter that's is way way past side milling, but just done another £300 of counter boring Monday & Tuesday with it. Finish is great customer is happy and its cost to me was sub 5 minutes of grinding :-) What's worse is i nearly gave that cutter and its brothers (they were all in one batch i acquired) away to someone else :-(

    If anything the edges of the flutes being well blunt seams to help it counter bore, sorta makes it self guiding - supporting like the lands on a drill bit.

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    Agree to that adama :

    Needing a job done and with no time to make a surface grinder set up it was not uncommon to just flat top off the end wear of an end mill with standing it up in a v-block or lay down in a v-block and side bump to the wheel, split the end flutes to center with one flute exact and the others short, back-off all other flutes to clearance angle to just tickle off the flat grind to sharp and they would work just like new.

    Just like hand sharpened drill a hand end-sharpened end mill works very well. The OD does the cutting as one is traversed across, and the end with a having little dish cuts flat only because the traverse generates the circle made by the outer tips of the corners. They might not last as long with not having exact clearance but they seemed to last almost as long.

    I do not recommended hand sharpening ODs but we had one fellow who could spiral a tool’s OD heal to the side of a bench grinder wheel to make a very nice looking OD (near perfect) back-off to a tool that was spun to size. He came from a shop that was noted for making specials where it was not uncommon to hand back-off new cutting tools (to an OD land) that were spun to size and step. I practiced hand back-off OD on scrap tools and finally got good at doing that myself.

    Buck

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  5. #24
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    I have been a tool & cutter grinder for 20 years now, and was a machinist building injection molds for 6 years previously, so maybe I have a reasonable perspective on this topic. First of all, there is a huge difference between salvaging a cutter for yourself in a pinch and doing it for a job. I have a Norton T&C, OK Tool T&C, Weldon air bearing, PW R-6 setup for roughers, a comparator, and tooling. Doing T&C grinding with surface grinders or Cuttermasters would be very limiting and slow. Also, as a professional, you need to do much more than end mills. I do a fair amount of modified cutters and specials as well as a variety of cutters.
    As to the value of regrinds. That depends on so many factors. Quality of the grinding. I have ground so many end mills previously done by someone else that were so bad, I can't imagine how they cut before. Usage. Some larger production shops hate to have regrinds because they have operator problems doing offsets on CNC machines. They feel safer with new end mills. On the other end, I used to grind a pair of matched OD slab mills for a motor manufacturer for $16.50. One day I was there when an operator was taking a pair off the machine. I asked how they worked. He said he had just run 14,000 shafts and was NOT done with that pair yet! That is obviously very cost effective. I regrind quite a few carbide specials that are expensive tools for a fraction of the price. Some of those are reground several times, making a huge savings.
    There are different ways to look at reground end mills as well. When milling mold cavities, I would often write a program for a ½" end mill, then run it with a reground end mill to rough it. Then put in the full ½" and finish cut. But making molds is doing one or two parts and then on to the next part. Very different from production.
    At any rate, I can't see messing around with grinding your own tools. Without good equipment and tooling you will waste so much time. Find a good grind shop and pay attention to what tools you are sending out. Are they worth regrinding or are they too wasted. 15% max. off the OD is a good reference point, beyond that they will not perform well. Hope this helps someone.

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  7. #25
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    keep the good carbide and hss, resharpen the carbide over 3/8 and sell the rest. For $2000 you will not be pleased with the sharpening equipment you will get.

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    If you think you are gonna make some money selling them after you have sharpened them, stop reading right now or you will be dissapointed. Selling resharpened or used endmills especially HSS is pointless unless you get them for free or nearly free. Selling endmills over 3/4 of an inch is nearly impossible. I have sold thousands of endmills no bullshit truckloads of them and it was barely worth it unless they were free. I was able to get a couple bucks each for regrinds of american made HSS in sizes up to 1/2 in. I paid 1500 dollars for 7000 endmills, I sold them all for 1 dollar each over the course of 5 days. They were all reground. I wouldnt bother sharpening them they are too cheap just get new ones, or go carbide insert.

  9. #27
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    If you have dull mills that you are going to toss anyhow, you can often make them work for cutting rusty steel, welds, and other things that will ruin a good end mill. Just hand grind a 45, or a radius on the corner of the flutes... Usually you can get 2 or 3 grinds this way. Sure beat wasting a decent cutter.

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  11. #28
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    Is there no money in scrap carbide? Do most used cutters just go in the steel scrap bin? Seems a pity since Tungsten is a strategic material.

  12. #29
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    A few years back scrap carbide was bringing $20 per pound, not sure where it is at today.

    I was looking at T&C grinders last night wondering whether or not to get one, not that I've ever used one, but with current location it will take minimum of 2 days to get an ordered replacement endmill.

    So if I'm reading this right I can resharpen endmills on a surface grinder? What fixtures would I need to resharpen endmills on a surface grinder?

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    Quote Originally Posted by dalmatiangirl61 View Post
    What fixtures would I need to resharpen endmills on a surface grinder?
    A fixture like this one is very common for sharpening the ends of endmills. The various angles let you grind primary and secondary clearances, and the holder rotates to index each flute in turn. Does nothing to sharpen the side-cutting edges, for which you really need a tool-and-cutter grinder.
    Attached Thumbnails Attached Thumbnails 85-090-001.jpg  

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  15. #31
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    Last week our plant sold about 2500 lbs of scrap carbide punches for $18 a pound, and they picked up and were hauling to the east coast somewhere.

    Dave

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    Quote Originally Posted by winger View Post
    Last week our plant sold about 2500 lbs of scrap carbide punches for $18 a pound, and they picked up and were hauling to the east coast somewhere.

    Dave
    $18/lb sounds like a very good price, if you could find out who the buyer was and post it I bet folks would appreciate it.

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    Quote Originally Posted by dalmatiangirl61 View Post
    A few years back scrap carbide was bringing $20 per pound, not sure where it is at today.

    I was looking at T&C grinders last night wondering whether or not to get one, not that I've ever used one, but with current location it will take minimum of 2 days to get an ordered replacement endmill.
    It can take a lot longer than 2 days to figure out how to even tool and utilize a proper T&C grinder that can do the flutes as well as the ends.

    And then one goes off on other work for a month and practically needs to re-train, next go. And/or doesn't have the right goods for a very different end-mill. Progressive helices, anyone?

    Hard enough for a full-time sharpening shop to keep up with all they need to be able to cover, skill and equipment-wise.

  18. #34
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    Quote Originally Posted by Monarchist View Post
    It can take a lot longer than 2 days to figure out how to even tool and utilize a proper T&C grinder that can do the flutes as well as the ends.

    And then one goes off on other work for a month and practically needs to re-train, next go. And/or doesn't have the right goods for a very different end-mill. Progressive helices, anyone?

    Hard enough for a full-time sharpening shop to keep up with all they need to be able to cover, skill and equipment-wise.
    I can accept that as an honest answer, but it does not take into account the complete lack of goods and services most of you enjoy. Case in point, lets say I need some decent name brand socks, from where I am currently, my only option is to order them and wait days for arrival, you really think getting machine tooling will be easier? Keep this between you and me, I'm the town eccentric, which means I might start a project Friday night, if I burn up an endmill that night I really don't want to wait till wednesday or thursday to complete the job. My needs are for myself only, it is clear as mud that there is no profit potential for doing it for others, to me it is simple self reliance. Sharpening ends of endmills is a plus, being able to sharpen sides would be a bonus. I've got plenty of HSS endmills to play with, what little carbide I use is mainly inserts.

    Anyone have suggestions on the easiest T&C grinder to use? I see lots of names and styles, not much info on any of them, or how to use them.

    There is currently a Pierce Model GA T&C grinder FS not too far away, approx 8 hour drive lol. Price looks cheap enough, seller is clueless to its application and is open to offers, is this a good, indiffeent, or crappy machine?

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    Quote Originally Posted by dalmatiangirl61 View Post
    say I need some decent name brand socks, from where I am currently, my only option is to order them and wait days for arrival
    So what? Ordered three bales of a dozen at a go, ("Diabetic" socks, here) they are cheaper, I never again have to MATCH the silly things, just bin the worn or damaged ones, pop open the next bale, order again when I open the last one. I could wait several MONTHS and not run-out.

    Endmills, Pilgrim, are much the same as socks. Consumable commodities.

    Lay-in a better minimum stock level - no fewer than three, each common type, two even on the odds - re-order in plenty of time, adjust your working to Just Not burn up the second one on any tasking you misjudged, FIRST go.

    Playing with a T&C grinder costs more.

    Learning to not "burn up" (or break..) endmills costs less.

    Address the disease. Not its symptoms.

    "only option" my aching ass. Texas ain't Antarctica. Ask a Kiwi or a West African about getting "stuff".

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  21. #36
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    Quote Originally Posted by dalmatiangirl61 View Post
    There is currently a Pierce Model GA T&C grinder FS not too far away, approx 8 hour drive lol. Price looks cheap enough, seller is clueless to its application and is open to offers, is this a good, indiffeent, or crappy machine?
    That machine will work for what you seem to want to do.
    Learning it will be a challenge without a mentor and it's not a fast stock remover but you don't need super fast grinding.
    Better than a surface grinder for the task but complicated until you "get it".
    Bob

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    Quote Originally Posted by CarbideBob View Post
    complicated until you "get it".
    Bob
    Oliver of Adrian, Royal Oak, Cincinnati, Knute Oscar Lee, Pratt & Whitney, B&S, LeBlond...... y'know what?

    None of them would HAVE to be so complicated if only we'd not kept inventing ever-more "complicated" milling-cutters 'stead of stopping with fly-cutters and "D" cutters..

    Yah wants yer performance? Yah pays the price..


  24. #38
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    I will see if the company will release the carbide buyers name monday. Ours were punches and ring of known composition. Not sure if coating will make a difference.

    On a side note, how do they recycle it? Chemically break it down, heat? I know with certain biocides and ph balance issues, the cobalt binder will leach out and cause pits in the punches.

    We make steel cans and any pits will show up as black streaks and eventually build up and cause tearoffs in the ironing process.

    Dave

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  26. #39
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    My understanding is that it's a chemical breakdown process: Tikomet Oy :: Recycling of hardmetal

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    Quote Originally Posted by Monarchist View Post

    "only option" my aching ass. Texas ain't Antarctica. Ask a Kiwi or a West African about getting "stuff".
    The Texas shop is not the problem, there is an MSC 45 minutes away. The new NV shop is a bit more remote, but I did look up MSC this morning and found they have a warehouse not too far away, only about 250 miles, or a 4 hour drive.

    It is rare for me to chowder an endmill in seconds, but it has happened, usually they just get dull. Most of my endmills are basic 2 and 4 flute, nothing fancy.

    Seller is asking $500 for Pierce T&C grinder, I suspect they would take less, tried to copy the pic to post here but it is not working, machine looks complete, but not sure if it should have attachments, I see none in pics. Having someone teach me how to use it would be best, I'm a quick learner that way, but sometimes you have to muddle through written instructions and just figure it out.


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