Endmill regrinding

Just dropped off about 30 lbs of end mills to be reground.
I have never done it before.
The regrinding shop has an awesome automated CNC end mill grinding
machine. I was told that you just insert the end mill in it and the machine figures out everything and costs $300,000. It is a technological wonder.
Their prices are $7 for a 1/2" end mill and $17 for a 1 inch end mill. I will see how it works out, I will probably sell the big 1 inchers and will keep the smaller ones.
i
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YOW! It wouldn't take long to pay for a Darex at those prices!
I happen to like (really like) pristine-sharp milling cutters, and being able to touch one up on-the-fly (as it were) would be a big benefit.
LLoyd
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On 2011-06-29, Lloyd E. Sponenburgh <lloydspinsidemindspring.com> wrote:

But would Darex really do that good of a job, compared to this CNC 8th wonder of the world?
And, additionally, how much time would I spend per end-mill with a Darex?
I am not trying to argue, I just want to try to consider this properly.

So, say, an angel comes from Heavens and brings me a Darex E-90.
How well will it really work for me, in real life?
i
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'Couldn't tell you, having not used one, but they come precious, even used, and high prices at re-sale usually mean they're well-accepted.
I have looked at the manuals and specs, and they spec-out as being able to do very precise re-grinding.
There's at least one on E-bay right now for under $2000, used.
LLoyd
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On 2011-06-30, Lloyd E. Sponenburgh <lloydspinsidemindspring.com> wrote:

Lloyd, I basically doubt that regrinding on my own is the right thing to do. This is what I want to clarify. I could justify an end mill grinder IF I can make money buying used end mills and sharpening. But I doubt that in the final analysis, it wil be proven to be worthwhile.
i
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That's where we differ, I guess. I figure I've used up all the "good" in a brand new HSS cutter in about an hour of optimum cutting (and with my old BOSS-9 machine, the spindle doesn't run fast enough to be at "optimum" very often). That, for me, ends up being about one part for most of the machines I build. Even a _slightly_ less-than-perfect sharpness results in much higher machining forces and worse surface finish. Using the wrong surface speeds and tooth loads worsens the wear, and I can't help those two problems right now. So I wear bits rapidly.
So it would be very nice to spend 3-5 minutes on a Darex and snap that "worn out" bit back up to correct sharpness for the next part. I can do the diameter compensations in my tool setups. I keep looking for a Darex E-90 I can both afford and is in good enough condition and well-enough equipped with collets to warrant spending the money.
LLoyd
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On 2011-06-30, Lloyd E. Sponenburgh <lloydspinsidemindspring.com> wrote:

Yep, tool diameter compensation is not a problem for me either.
I still would like to know how much time DIY regrinding takes, and whether it is as good as a $7 apiece CNC job.
i
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On 6/29/2011 8:25 PM, Ignoramus20088 wrote:

I looked one over once and was not exactly impressed with the rigidity of the unit. Oh, you can sharpen an end mill for sure. But will it be the equal of the CNC sharpened mill? I very much doubt it.
If you want to make money sharpening mills, you need that fancy CNC machine IMHO...
Jon
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I thought along those lines.

Which makes sense, economically. Just 2 weeks ago, I participated in liquidation of an end mill regrinding shop equipped with old style stuff (KO Lee, Cinci etc).
i
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On Thu, 30 Jun 2011 12:44:13 -0500, Ignoramus18155

What kind of prices did the tool and cutter grinders bring at auction?
Was the tooling with the machines or sold separately?
RWL
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On 2011-07-02, GeoLane at PTD dot NET <GeoLane> wrote:

They did not sell and were attractively priced.
I got a bunch of diamond grinding wheels.

Some was, some was not, I got a couple dozen diamond wheels.
i
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On Fri, 01 Jul 2011 23:01:58 -0500, Ignoramus2853

What were they asking for them?
Here on the east coast I'm seeing them sporadically on Craigslist in a wide range of prices. The full sized ones are almost always KO Lee rather than Cincinnattis. An occasional other brand. Among recent prices, the low end was $650, another at $950 and a grinding shop that was closing asking $1500 for their KO Lee's. One from Quakertown PA started at $2000 and about 6 months later dropped it to $1500 - and you had to remove it from the guys cellar. Most of the ones I'm seeing come only with a single specific piece of tooling, and sometimes a set of centers.
Prior to this past year or so, I don't recall seeing any tool and cutter grinders on the nearby Craigs lists.
I have two of the KO Lees and am now looking for selected pieces of tooling - in particular, the universal grinding fixture, the motorized grinding fixture for cylindrical grinding, and the radius fixture for turning ball nose end mills.
RWL
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wrote:

I've watched ebay sporadically, but it seems that only dealers are populating the sales with ridiculous prices that are 2x to 4x higher than a home shop machinist would pay. In looking at completed sales, very little is selling.
RWL
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On Jul 3, 7:35pm, GeoLane at PTD dot NET <GeoLane at PTD dot NET> wrote:

Too expensive for me, but... http://www.tools4cheap.net/proddetail.php?prod=radattach
This was about my limit: http://www.tools4cheap.net/proddetail.php?prod=univise I bought it to grind the gear tooth cutter to fix the tractor. Adapting other tooling like a 5C spin index to it shouldn't be difficult.
jsw
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There's a better price for these on ebay.
http://cgi.ebay.com/UNIVERSAL-VISE-MILL-GRINDER-FIXTURE-BRAND-NEW-/140570519903?pt=BI_Tool_Work_Holding&hash=item20baa7e95f
RWL
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On Jul 4, 11:04pm, GeoLane at PTD dot NET <GeoLane at PTD dot NET> wrote:

Within reason I try to support the local dealers where I can examine the goods and return anything defective. That guy found some half- price toolholders that fit my Swiss Multifix and more importantly took the risk that they wouldn't fit well enough. They do, perfectly. https://picasaweb.google.com/KB1DAL/HomeMadeMachines#5107533382447691698
Lindsay now has the rebuilding book for these larger South Bend lathes. I didn't see it on their web site, but it's # 1649 in the paper catalog. http://cgi.ebay.com/NEW-Rebuild-Book-South-Bend-Lathe-10L-13-14-5-16-/160546638223
jsw
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On 2011-07-03, GeoLane at PTD dot NET <GeoLane> wrote:

I call them "dreamers".
i
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That stuff sits on the shelf until thier grand kids sell it for scrap.
Best Regards Tom.
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On Jun 29, 6:27pm, Ignoramus20088 <ignoramus20...@NOSPAM. 20088.invalid> wrote:

...
...
FWIW, I have a Darex spindle that I can mount to my tool and cutter grinder.
It's been a few years since I've sharpened any endmills with this set up. "Unfortunately", I keep scoring new ones at ridiculous low prices so I don't need to sharpen very often. :-)
<Tool gloat could go here but I don't wish to make anyone feel bad.>
A few comments from what I remember...
My initial setup is a bit more troublesome than using the full grinder. Needs air, and I have to "clock" in everything.
That lever does a nice job at positioning the spindle for the secondary. It's just hit the lever and you're there.
Getting the primary can be a bit more troublesome. If you are not careful, you can take off an extra thou or more. And once you take too much off the first flute, you need to take the same off the others.
If all of your endmills are the same diameter, then once you've got the first one "on". then the rest are no problem.
It's just when you need to change something that you must spend extra time.
The ends are no more difficult than the sides and the machine automatically "fish tails" them. The only problem I ever had with the ends was when there are only two flutes and you need to sharpen one side that extends across the center. There's an easy "oops" moment here. And then you need to do them both again.
I just looked up the price and had that sticker shock reaction.
Altogether a nice machine and easy to use. Fine to sharpen a few dozen, but after you've done the first several, it tends to get tedious. I wouldn't want to do this for hours on end.
DOC
Turners just keep going round and round!
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Ignoramus20088 wrote:

There are some really nice toys out there. I presume the machine laser marks the new dimension on the end mill so you have the correct info for your cutter comp.

Sounds a tad expensive, I expect if you did regular commercial business with them the prices would be lower.
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